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1.  Dissection by Ultrasonic Energy Versus Monopolar Electrosurgical Energy in Laparoscopic Cholecystectomy 
Ultrasonic dissection was found to be superior to monopolar electrosurgical dissection; however, the Harmonic dissecting unit was found to be more difficult to maneuver and cost more.
Laparoscopic cholecystectomy is the gold standard for management of symptomatic gallstones. Electrocautery remains the main energy form used during laparoscopic dissection. However, due to its risks, search is continuous for safer and more efficient forms of energy. This review assesses the effects of dissection using ultrasonic energy compared with monopolar electrocautery during laparoscopic cholecystectomy.
A literature search of the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE, and EMBASE was performed. Studies included were trials that prospectively randomized adult patients with symptomatic gallstone disease to either ultrasonic or monopolar electrocautery dissection during laparoscopic cholecystectomy. Data were collected regarding the characteristics and methodological quality of each trial. Outcome measures included operating time, gallbladder perforation rate, bleeding, bile leak, conversion rate, length of hospital stay and sick leave, postoperative pain and nausea scores, and influence on systemic immune and inflammatory responses. For metaanalysis, the statistical package RevMan version 4.2 was used. For continuous data, Weighted Mean Difference (WMD) was calculated with 95% confidence interval (CI) using the fixed effects model. For Categorical data, the Odds Ratio (OR) was calculated with 95% confidence interval using fixed effects model.
Seven trials were included in this review, with a total number of 695 patients randomized to 2 dissection methods: 340 in the electrocautery group and 355 in the ultrasonic group. No mortality was recorded in any of the trials. With ultrasonic dissection, operating time is significantly shorter in elective surgery (WMD −8.19, 95% CI −10.36 to −6.02, P>0.0001), acute cholecystitis (WMD −17, 95% CI −28.68 to −5.32, P=0.004), complicated cases (WMD −15, 95% CI −28.15 to −1.85, P=0.03), or if surgery was performed by trainee surgeons who had performed >10 procedures (P=0.043). Gallbladder perforation risk with bile leak or stone loss is lower (OR 0.27, 95% CI 0.17 to 0.42, P>0.0001 and OR 0.13, 95% CI 0.04 to 0.47, P=0.002 respectively), particularly in the subgroup of complicated cases (OR 0.24 95% CI 0.09 to 0.61, P=0.003). Mean durations of hospital stay and sick leave were shorter with ultrasonic dissection (WMD −0.3, 95% CI −0.51 to −0.09, P=0.005 and WMD −3.8, 95% CI −6.21 to −1.39, P=0.002 respectively), with a smaller mean number of patients who stayed overnight in the hospital (OR 0.18, 95% CI 0.03 to 0.89, P=0.04). Postoperative abdominal pain scores at 1, 4, and 24 hours were significantly lower with ultrasonic dissection as were postoperative nausea scores at 2, 4, and 24 hours.
Based on a few trials with relatively small patient samples, this review does not attempt to advocate the use of a single-dissection technology but rather to elucidate results that could be used in future trials and analyses. It demonstrates, with statistical significance, a shorter operating time, hospital stay and sick leave, lower gallbladder perforation risk especially in complicated cases, and lower pain and nausea scores at different postoperative time points. However, many of these potential benefits are subjective, and prone to selection, and expectation bias because most included trials are unblinded. Also the clinical significance of these statistical results has yet to be proved. The main disadvantages are the difficulty in Harmonic scalpel handling, and cost. Appropriate training programs may be implemented to overcome the first disadvantage. Cost remains the main universal issue with current ultrasonic devices, which outweighs the potential clinical benefits (if any), indicating the need for further cost-benefit analysis.
PMCID: PMC3021294  PMID: 20412640
Ultrasonic dissection; Electrocautery; Electrosurgical energy
2.  Comparing Scalpel, Electrocautery and Ultrasonic Dissector Effects: The Impact on Wound Complications and Pro-Inflammatory Cytokine Levels in Wound Fluid from Mastectomy Patients 
Journal of Breast Cancer  2011;14(1):58-63.
Introducing the relationship between the surgical instruments used in modified radical mastectomy and wound complications is important for preventing and decreasing complications. This prospective randomized trial was designed to assess the impact of scalpel, electrocautery, and ultrasonic dissector usage on wound complications and tissue damage.
Eighty-two consecutive patients operated with mastectomy were studied. The postoperative time period needed for hemovac drainage, the amount and duration of seroma, infection, flap ecchymosis and necrosis rates were compared. Tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) levels in drainage fluids were determined to confirm the inflammatory response and tissue damage.
The numbers of patients included in the scalpel, electrocautery and ultrasonic dissector groups were 27, 26, and 29, respectively. The groups were homogenous with respect to age, body mass index, stage, cormorbidities, breast volume and flap area. Operation time and the amount of bleeding were statistically higher in the scalpel group. The incidence of seroma was higher in the electrocautery group and arm mobilization had to be delayed in this group. There were no differences between groups with respect to hematoma, infection, ecchymosis, necrosis, hemovac drainage and the total and first 3 days of seroma volume. TNF-α and IL-6 levels were significantly higher in samples obtained from the drains of patients operated with electrocautery.
Ultrasonic dissector decreases operation time by decreasing the amount of bleeding without increasing the seroma incidence. High cytokine levels in drainage fluids from patients operated with elecrocautery indicates that electrocautery induces more tissue damage and acute inflammatory response. Therefore, seroma, due to acute inflammatory response, was seen more frequently in the electrocautery group. Ultrasonic dissector coagulates protein by breaking hydrogen bonds which may close vascular and lymphatic channels more precisely. But, its actual preventive effect on seroma formation might be related to diminished inflammatory response.
PMCID: PMC3148508  PMID: 21847396
Breast; Carcinoma; Interleukin-6; Seroma; Tumor necrosis factor alpha
3.  Radiofrequency-Assisted Laparoscopic Partial Nephrectomy: Clinical and Histologic Results 
To evaluate a surface conductive radiofrequency (RF) coagulation instrument (Tissuelink FB3.0) in laparoscopic and open partial nephrectomy (PN) in hereditary kidney cancer. The lesion depth and viability in the pathologic specimens from a surgical series and an acute porcine model were characterized under conditions of vascular perfusion and occlusion.
Materials and Methods:
A total of 19 patients underwent 20 laparoscopic and open procedures with the device. Data were acquired on tumor number, size, operative time, blood loss, length of stay, renal function, complications, pathologic diagnosis, and surgical-margin status. Renal lesions were created in pigs with the device, ultrasonic shears, and a standard electrocautery for specified time intervals and operative energy settings. These lesions were analyzed for depth, diameter, and tissue viability.
In 20 separate (14 laparoscopic; 6 open) procedures in 19 patients, a total of 112 tumors were removed (range 1–31 tumors per procedure). The median operative time, blood loss, and length of stay were 310 minutes, 250 mL, and 4 days, respectively. There were no positive surgical margins. Median preoperative and postoperative creatinine concentrations were similar (1.0 v 1.0 mg/dL). The average treatment margin depth was 3 mm. In the porcine experiments, the treatment depth in the unclamped vascular model was significantly less in than the clamped model (4.0 ± 1.7 mm v 7.0 ± 1.6 mm; P < 0.05). Lesion depth and diameter increased with treatment time. Viability depth correlated well with the depth of the visible thermal lesions (Pearson correlation 0.989).
This RF energy device can provided adequate and uniform hemostatic control without hilar clamping during laparoscopic and open PN for hereditary renal tumors. Gross measures of renal function after surgery appeared clinically unchanged. Coagulation depth is dependent on both tissue perfusion and time in the porcine model.
PMCID: PMC2621257  PMID: 17638553
4.  Collateral Tissue Damage by Several Types of Coagulation (Monopolar, Bipolar, Cold Plasma and Ultrasonic) in a Minimally Invasive, Perfused Liver Model 
ISRN Surgery  2011;2011:518924.
Hemostasis in minimally invasive surgery causes tissue damage. Regardless of the method of production of thermal energy, a quick and safe coagulation is essential for its clinical use. In this study we examined the tissue damage in the isolated perfused pig liver using monopolar, bipolar, cold plasma, and ultrasonic coagulation. In a minimally invasive in vitro setup, a 2-3 cm slice of the edge of the perfused pig liver was resected. After hemostasis was achieved, liver tissue of the coagulated area was given to histopathological examination. The depth of tissue necrosis, the height of tissue loss, and the time until sufficient hemostasis was reached were analyzed. The lowest risk for extensive tissue damage could be shown for the bipolar technique, combined with the highest efficiency in hemostasis. Using cold plasma, coagulation time was longer with a deeper tissue damage. Monopolar technique showed the worst results with the highest tissue damage and a long coagulation time. Ultrasonic coagulation was not useful for coagulation of large bleeding areas. In summary, bipolar technique led to less tissue damage and best coagulation results in our minimally invasive model. These results could be important to recommend bipolar coagulation for clinical use in minimally invasive surgery.
PMCID: PMC3200089  PMID: 22084761
5.  Comparison of local tissue damage: monopolar cutter versus Nd:YAG laser for lung parenchyma resection. An experimental study 
Lung metastases are non-anatomically resected while sparing as much parenchyma as possible. For this purpose, a few surgeons use the Nd:YAG Laser LIMAX® 120, whereas the majority of surgeons use a monopolar cutter like the MAXIUM®. The aim of this experimental study was to investigate which instrument causes less lung-tissue damage at the same power output.
These experiments were conducted on left lungs (n = 6) taken from freshly slaughtered pigs. The laser and the monopolar cutter were fixed in a hydraulic mover. The laser was focused at a distance of 3 cm to the lung tissue and the monopolar cutter was fixed in pressure-free contact with the lung surface. Both instruments were manoeuvred at a speed of 5, 10 and 20 mm/s in a straight line at an output of 100 watts over the lung surface. The lung lesions that ensued were then examined macro- and microscopically. The same procedures were repeated at a distance of 1 cm creating parallel lesions in order to analyse the lung tissue in between the lesions for thermal damage. In addition, two implanted capsules in the lung tissue simulating a lung nodule were resected with either the laser or the monopolar cutter. The resection surfaces were then examined by magnetic resonance imaging and histology for tissue damage. Finally, we created a 2-cm wide mark on the lung surface to test the resection capacity of both instruments within 1 min.
The laser created sharply delineated lesions with a vaporization and coagulation zone without thermal damage of the surrounding lung tissue. With lowering the working speed, each zone was extended. At a working speed of 10 mm/s, the mean vaporization depth using the laser was 1.74 ± 0.1 mm and the mean coagulation depth was 1.55 ± 0.09 mm. At the same working speed, the monopolar cutter demonstrated a greater cutting effect (mean vaporization depth 2.7 ± 0.11 mm; P < 0.001) without leaving much coagulation on the resection surface (mean coagulation depth 1.25 ± 0.1 mm; P = 0.002). In contrast to the laser, the monopolar cutter caused thermal damage of the adjacent lung tissue. The adjacent tissue injury was detected in histological examination as well as in the MRI findings. Adjacent lung tissue after lung metastasectomy using the monopolar cutter was hyper-intensive in T2-weighted MR imaging, indicating a severe tissue damage. No significant changes in signal intensity were observed in T2-weighted imaging of the adjacent lung tissue after using the laser for lung resection. One minute of laser applied at a 100-watt output penetrated a lung surface area of 3.8 ± 0.4 cm2 compared with 4.8 ± 0.6 cm2 of surface after application of the monopolar cutter (P = 0.001).
The monopolar cutter possesses indeed a greater cutting capacity than the laser, but it also causes more adjacent tissue injury. Thus, laser resection might be preferred for lung metastasectomy.
PMCID: PMC3867036  PMID: 24130089
Electrosurgical scalpel; Laser; Lung metastases; Lung resection; Tissue damage
6.  Comparison of lateral thermal damage of the human peritoneum using monopolar diathermy, Harmonic scalpel and LigaSure 
Canadian Journal of Surgery  2012;55(5):317-321.
New hemostatic technologies are often employed in open and laparoscopic surgery to reduce duration of surgery and complications. Monopolar diathermy, Harmonic scalpel and LigaSure are routinely used in open and laparoscopic surgery for tissue cutting and hemostasis. We compared lateral thermal damage following in vivo application of 3 commonly used instruments.
We used monopolar diathermy, Harmonic scalpel and LigaSure to coagulate and divide the peritoneum of patients who underwent median laparotomy. After anesthesia, median supraumbilical laparotomy was performed, and the peritoneum of each patient was coagulated using different devices. Using light microscopy and morphometric imaging analysis, the width of tissue lateral thermal damage was measured from the point of the peritoneal incision.
We included 100 patients in our study. After a peritoneal incision, the mean lateral thermal damage of monopolar diathermy, Harmonic scalpel (output power 3), Harmonic scalpel (output power 5) and LigaSure were 215.79 μm, 90.42 μm, 127.48 μm and 144.18 μm, respectively.
The degree of lateral thermal spread varied by instrument type, power setting and application time. LigaSure and Harmonic scalpel were the safest and most efficient methods of tissue coagulation. Monopolar diathermy resulted in the greatest degree of thermal damage in tissues.
PMCID: PMC3468644  PMID: 22854112
7.  Use of an ultrasonic osteotome device in spine surgery: experience from the first 128 patients 
European Spine Journal  2013;22(12):2845-2849.
The ultrasonic BoneScalpel is a tissue-specific device that allows the surgeon to make precise osteotomies while protecting collateral or adjacent soft tissue structures. The device is comprised of a blunt ultrasonic blade that oscillates at over 22,500 cycles/s with an imperceptible microscopic amplitude. The recurring impacts pulverize the noncompliant crystalline structure resulting in a precise cut. The more compliant adjacent soft tissue is not affected by the ultrasonic oscillation. The purpose of this study is to report the experience and safety of using this ultrasonic osteotome device in a variety of spine surgeries.
Data were retrospectively collected from medical charts and surgical reports for each surgery in which the ultrasonic scalpel was used to perform any type of osteotomy (facetectomy, laminotomy, laminectomy, en bloc resection, Smith Petersen osteotomy, pedicle subtraction osteotomy, etc.). The majority of patients had spinal stenosis, degenerative or adolescent scoliosis, pseudoarthrosis, adjacent segment degeneration, and spondylolisthesis et al. Intra-operative complications were also recorded.
A total of 128 consecutive patients (73 female, 55 male) beginning with our first case experience were included in this study. The mean age of the patients was 58 years (range 12–85 years). Eighty patients (62.5 %) had previous spine surgery and/or spinal deformity. The ultrasonic scalpel was used at all levels of the spine and the average levels operated on each patient were 5. The mean operation time (skin to skin) was 4.3 h and the mean blood loss was 425.4 ml. In all cases, the ultrasonic scalpel was used to create the needed osteotomies to facilitate the surgical procedure without any percussion on the spinal column or injury to the underlying nerves. There was a noticeable absence of bleeding from the cut end of the bone consistent with the ultrasonic application. There were 11 instances of dural injuries (8.6 %) and two of which were directly associated with the use of ultrasonic device. In no procedure was the use of the ultrasonic scalpel abandoned for use of another instrument due to difficulty in using the device or failure to achieve the desired osteotomy.
Overall, the ultrasonic scalpel was safe and performed as desired when used as a bone cutting device to facilitate osteotomies in a variety of spine surgeries. However, caution should be taken to avoid potential thermal injury and dural tear. If used properly, this device may decrease the risk of soft tissue injury associated with the use of high speed burrs and oscillating saws during spine surgery.
PMCID: PMC3843782  PMID: 23584231
Ultrasonic scalpel; Spine surgery; Osteotomy; Safety; Dural injury
8.  Dissection Technique for Abdominoplasty: A Prospective Study on Scalpel versus Diathermocoagulation (Coagulation Mode) 
The purpose of this study was to evaluate the effect of the dissection technique on outcomes and complications after a full abdominoplasty, comparing 2 different techniques used to raise the abdominal flap: the steel scalpel and the diathermocoagulation device on coagulation mode.
A prospective study was performed at a single center from January 2009 to December 2011 of patients submitted to abdominoplasty with umbilical transposition. Two groups were identified: group A, abdominoplasty performed with steel scalpel/knife; and group B, abdominoplasty performed with diathermocoagulation on coagulation mode. Several variables were determined: general characteristics, time until drain removal, daily and total volume of drain output, length of hospital stay, operative time, readmission, reoperation, emergency department visits, and local and systemic complications.
A total of 119 full abdominoplasties were performed in women (group A, 39 patients; group B, 80 patients). There were no statistically significant differences between groups with respect to general characteristics, except for body mass index, comorbidities, and weight of the surgical specimen; there were no differences for operative time, systemic complications, hematoma, and necrosis incidence. The scalpel group had a highly significant reduction of 54.56% on total drain output, and a 2.65 day reduction on time to drain removal and no reported cases of seroma or healing problems (difference of 81.25% and 90.00%, respectively, between the 2 groups).
Performing abdominal dissection with scalpel had a beneficial effect on patient recovery, as it reduced time requested for drain removal, total drain output, and incidence of seroma and wound healing problems.
PMCID: PMC4323403
9.  Monopolar electrocautery versus ultrasonic dissection of the gallbladder from the gallbladder bed in laparoscopic cholecystectomy: a randomized controlled trial 
Canadian Journal of Surgery  2012;55(5):307-311.
Ultrasonic dissection has been suggested as an alternative to monopolar electrocautery in laparoscopic cholecystectomy because it generates less tissue damage and may have a lower incidence of gallbladder perforation. We compared the 2 methods to determine the incidence of gallbladder perforation and its intraoperative consequences.
We conducted a prospective randomized controlled trial between July 2008 and December 2009 involving adult patients with symptomatic gall stone disease who were eligible for laparoscopic cholecystectomy. Patients were randomly assigned before administration of anesthesia to electrocautery or ultrasonic dissection. Both groups were compared for incidence of gallbladder perforation during dissection, bile leak, stones spillage, lens cleaning, duration of surgery and estimation of risk of gall-bladder in the presence of complicating factors.
We included 60 adult patients in our study. The groups were comparable with respect to demographic characteristics, symptomatology, comorbidities, previous abdominal surgeries, preoperative ultrasonography findings and intraoperative complications. The overall incidence of gallbladder perforation was 28.3% (40.0% in the electrocautery v. 16.7% in the ultrasonic dissection group, p = 0.045). Bile leak occurred in 40.0% of patients in the electrocautery group and 16.7% of patients in ultrasonic group (p = 0.045). Lens cleaning time (p = 0.015) and duration of surgery (p = 0.001) were longer in the electrocautery than the ultrasonic dissection group. There was no statistical difference in stone spillage between the groups (p = 0.62).
Ultrasonic dissection is safe and effective, and it improves the operative course of laparoscopic cholecystectomy by reducing the incidence of gallbladder perforation.
PMCID: PMC3468642  PMID: 22854110
10.  Saline-Enhanced Hepatic Radiofrequency Ablation Using a Perfused-Cooled Electrode: Comparison of Dual Probe Bipolar Mode with Monopolar and Single Probe Bipolar Modes 
Korean Journal of Radiology  2004;5(2):121-127.
To determine whether saline-enhanced dual probe bipolar radiofrequency ablation (RFA) using perfused-cooled electrodes shows better in-vitro efficiency than monopolar or single probe bipolar RFA in creating larger coagulation necrosis.
Materials and Methods
RF was applied to excised bovine livers in both bipolar and monopolar modes using a 200W generator (CC-3; Radionics) and the perfused-cooled electrodes for 10 mins. After placing single or double perfused-cooled electrodes in the explanted liver, 30 ablation zones were created at three different regimens: group A; saline-enhanced monopolar RFA, group B; saline-enhanced single probe bipolar RFA, and group C; saline-enhanced dual probe bipolar RFA. During RFA, we measured the tissue temperature at 15mm from the electrode. The dimensions of the ablation zones and changes in the impedance currents and liver temperature during RFA were then compared between the groups.
The mean current values were higher for monopolar mode (group A) than for the bipolar modes (groups B and C): 1550±25 mA in group A, 764±189 mA in group B and 819±98 mA in group C (p < 0.05). The volume of RF-induced coagulation necrosis was greater in group C than in the other groups: 27.6±2.9 cm3 in group A, 23.7±3.8 cm3 in group B, and 34.2±5.1 cm3 in group C (p < 0.05). However, there was no significant difference between the short-axis diameter of the coagulation necrosis in the three groups: 3.1±0.8 cm, 2.9±1.2 cm and 4.0±1.3 cm in groups A, B and C, respectively (p > 0.05). The temperature at 15 mm from the electrode was higher in group C than in the other groups: 70±18℃ in group A, 59±23℃ in group B and 96±16℃ in group C (p < 0.05).
Saline-enhanced bipolar RFA using dual perfused-cooled electrodes increases the dimension of the ablation zone more efficiently than monopolar RFA or single probe bipolar RFA.
PMCID: PMC2698140  PMID: 15235237
Liver, interventional procedures; Radiofrequency ablation; Experimental study
11.  Surgical smoke and ultrafine particles 
Electrocautery, laser tissue ablation, and ultrasonic scalpel tissue dissection all generate a 'surgical smoke' containing ultrafine (<100 nm) and accumulation mode particles (< 1 μm). Epidemiological and toxicological studies have shown that exposure to particulate air pollution is associated with adverse cardiovascular and respiratory health effects.
To measure the amount of generated particulates in 'surgical smoke' during different surgical procedures and to quantify the particle number concentration for operation room personnel a condensation particle counter (CPC, model 3007, TSI Inc.) was applied.
Electro-cauterization and argon plasma tissue coagulation induced the production of very high number concentration (> 100000 cm-3) of particles in the diameter range of 10 nm to 1 μm. The peak concentration was confined to the immediate local surrounding of the production side. In the presence of a very efficient air conditioning system the increment and decrement of ultrafine particle occurrence was a matter of seconds, with accumulation of lower particle number concentrations in the operation room for only a few minutes.
Our investigation showed a short term very high exposure to ultrafine particles for surgeons and close assisting operating personnel – alternating with longer periods of low exposure.
PMCID: PMC2621226  PMID: 19055750
12.  Optimization of Wet Radiofrequency Ablation Using a Perfused-Cooled Electrode: A Comparative Study in Ex Vivo Bovine Livers 
Korean Journal of Radiology  2004;5(4):250-257.
To determine the optimized protocol for wet monopolar radiofrequency ablation (RFA) using a perfused-cooled electrode to induce coagulation necrosis in the ex vivo bovine liver.
Materials and Methods
Radiofrequency was applied to excised bovine livers in a monopolar mode using a 200W generator with an internally cooled electrode (groups A and B) or a perfused-cooled electrode (groups C, D, E, and F) at maximum power (150-200 W) for 10 minutes. A total of 60 ablation zones were created with six different regimens: group A - dry RFA using intra-electrode cooling; group B - dry RFA using intra-electrode cooling and a pulsing algorithm; group C - wet RFA using only interstitial hypertonic saline (HS) infusion; group D - wet RFA using interstitial HS infusion and a pulsing algorithm; group E - wet RFA using interstitial HS infusion and intra-electrode cooling; and group F - wet RFA using interstitial HS infusion, intra-electrode cooling and a pulsing algorithm. In groups C, D, E, and F, RFA was performed with the infusion of 6% HS through the perfused cooled electrode at a rate of 2 mL/minute. During RFA, we measured the tissue temperature at a distance of 15 mm from the electrode. The dimensions of the ablation zones and the changes in impedance, currents, and liver temperature during RFA were compared between these six groups.
During RFA, the mean tissue impedances in groups A (243 ± 88 Ω) and C (252.5 ± 108 Ω) were significantly higher than those in groups B (85 ± 18.7 Ω), D (108.2 ± 85 Ω), E (70.0 ± 16.3 Ω), and F (66.5 ± 7 Ω) (p < 0.05). The mean currents in groups E and F were significantly higher than those in groups B and D, which were significantly higher than those in groups A and C (p < 0.05): 520 ± 425 mA in group A, 1163 ± 34 mA in group B, 652.5 ± 418 mA in group C, 842.5 ± 773 mA in group D, 1665 ± 295 mA in group E, and 1830 ± 109 mA in group F. The mean volumes of the ablation regions in groups E and F were significantly larger than those in the other groups (p < 0.05): 17.7 ± 5.6 cm3 in group A, 34.5 ± 3.0 cm3 in group B, 20.2 ± 15.6 cm3 in group C, 36.1 ± 19.5 cm3 in group D, 68.1 ± 12.4 cm3 in group E, and 79.5 ± 31 cm3 in group F. The final tissue temperatures at a distance of 15 mm from the electrode were higher in groups E and F than those in groups A, C, and D (p < 0.05): 50 ± 7.5℃ in group A, 66 ± 13.6℃ in group B, 60 ± 13.4℃ in group C, 61 ±12.7℃ in group D, 78 ± 14.2℃ in group E, and 79 ± 12.0℃ in group F.
Wet monopolar RFA, using intra-electrode cooling and interstitial saline infusion, showed better performance in creating a large ablation zone than either dry RFA or wet RFA without intra-electrode cooling.
PMCID: PMC2698169  PMID: 15637475
Experimental study; Interventional procedures; Liver; Radiofrequency ablation
13.  Histological and morphometric analysis of the effects of argon laser epilation 
Aim: To analyse the location and extent of tissue damage induced after argon laser epilation.
Methods: Laser burns were applied to the lid margins of four patients before excision for entropion (“live tissue”) and the lid margin of one patient was lasered after an excision for ectropion (“dead tissue”). The laser burns were directed towards the lash follicle and between 10 and 50 burns were applied with an argon blue-green laser set at power 0.9–1.0 W, at 0.1–0.2 second duration and a 100 μm spot size. The tissues were processed for conventional histology. Serial sections were obtained and used for area measurements and three dimensional reconstructions of the burns to determine the volume and location of tissue destruction.
Results: The laser created a cone-shaped region of tissue ablation with surrounding coagulative necroses. Maximum burn depth was 1.2 mm in dead tissue and 0.8 mm in live tissue. Maximum necrosis depth was 1.4 mm in dead tissue and 0.9 mm in live tissue. Follicle depth ranged from 0.8 mm to 1.9 mm. Some of the burns had been misdirected in the dermis leaving target hair follicles intact, despite being of adequate depth.
Conclusions: The argon laser has some potential for ablation of lash follicles, but accurate placement of the burn is essential and energy levels greater than those currently recommended should be applied. The treatment is ineffective in patients unable to remain immobile.
PMCID: PMC1771803  PMID: 12881341
argon laser; epilation; tissue damage
14.  Electrocautery causes more ischemic peritoneal tissue damage than ultrasonic dissection 
Surgical Endoscopy  2010;25(6):1827-1834.
Minimizing peritoneal tissue injury during abdominal surgery has the benefit of reducing postoperative inflammatory response, pain, and adhesion formation. Ultrasonic dissection seems to reduce tissue damage. This study aimed to compare electrocautery and ultrasonic dissection in terms of peritoneal tissue ischemia measured by microdialysis.
In this study, 18 Wistar rats underwent a median laparotomy and had a peritoneal microdialysis catheter implanted in the left lateral sidewall. The animals were randomly assigned to receive two standard peritoneal incisions parallel to the catheter by either ultrasonic dissection or electrocautery. After the operation, samples of microdialysis dialysate were taken every 2 h until 72 h postoperatively for measurements of pyruvate, lactate, glucose, and glycerol, and ratios were calculated.
The mean lactate–pyruvate ratio (LPR), lactate–glucose ratio (LGR), and glycerol concentration were significantly higher in the electrocautery group than in the ultrasonic dissection group until respectively 34, 48, and 48 h after surgery. The mean areas under the curve (AUC) of LPR, LGR, and glycerol concentration also were higher in the electrocautery group than in the ultrasonic dissection group (4,387 vs. 1,639, P = 0.011; 59 vs. 21, P = 0.008; 7,438 vs. 4,169, P = 0.008, respectively).
Electrosurgery causes more ischemic peritoneal tissue damage than ultrasonic dissection.
PMCID: PMC3109994  PMID: 21140171
Adhesions; Electrocautery; Ischemia; Microdialysis; Ultrasonic dissection
15.  Design of a factorial experiment with randomization restrictions to assess medical device performance on vascular tissue 
Energy-based surgical scalpels are designed to efficiently transect and seal blood vessels using thermal energy to promote protein denaturation and coagulation. Assessment and design improvement of ultrasonic scalpel performance relies on both in vivo and ex vivo testing. The objective of this work was to design and implement a robust, experimental test matrix with randomization restrictions and predictive statistical power, which allowed for identification of those experimental variables that may affect the quality of the seal obtained ex vivo.
The design of the experiment included three factors: temperature (two levels); the type of solution used to perfuse the artery during transection (three types); and artery type (two types) resulting in a total of twelve possible treatment combinations. Burst pressures of porcine carotid and renal arteries sealed ex vivo were assigned as the response variable.
The experimental test matrix was designed and carried out as a split-plot experiment in order to assess the contributions of several variables and their interactions while accounting for randomization restrictions present in the experimental setup. The statistical software package SAS was utilized and PROC MIXED was used to account for the randomization restrictions in the split-plot design. The combination of temperature, solution, and vessel type had a statistically significant impact on seal quality.
The design and implementation of a split-plot experimental test-matrix provided a mechanism for addressing the existing technical randomization restrictions of ex vivo ultrasonic scalpel performance testing, while preserving the ability to examine the potential effects of independent factors or variables. This method for generating the experimental design and the statistical analyses of the resulting data are adaptable to a wide variety of experimental problems involving large-scale tissue-based studies of medical or experimental device efficacy and performance.
PMCID: PMC3120810  PMID: 21599963
Factorial design; split-plot design, randomization restrictions; vascular; biostatistics; burst pressure
16.  Use of Ultrasonic Shears in Patients with Breast Cancer Undergoing Axillary Dissection—A Pilot Study 
Patients with breast cancer and positive sentinel node biopsy usually require axillary dissection. Different instruments are used for axillary dissection like regular scalpel,monopolar cautery, bipolar cautery etc. All these instruments are having its advantages and disadvantages. Our dept did a pilot study to know the efficacy of ultrasonic shears over cautery for axillary dissection. Parameters considered were cumulative drain amount, number of days with the drain and number of lymphnodes harvested. Ultrasonic shear machine delivers precisely directed mechanical energy with an ultrasonic vibrating blade.A single device dissects, cuts, grasps, spot coagulates. This machine was used for doing axillary dissection in one group and regular cautery in the other group. Study period was from April 2011 to June 2011 at Dept of Surgical Oncology, St Johns Hospital, Bangalore. Nine people in the ultrasonic shear group and 11 people in the cautery group were included in the pilot study. No significant difference were noticed in the cumulative drain amount, number of days with the drain, and number of lymphnodes harvested in both the groups. Axillary dissection using ultrasonic shears do not show any significant difference in the cumulative drain amount, number of days with the drain, and number of lymphnodes harvested. These are the findings of the pilot study, further prospective randomized studies are required for substantiating the findings.
PMCID: PMC3272170  PMID: 22942604
Breast; Cancer; Cautery; Ultrasonic shears
17.  Traditional electrosurgery and a low thermal injury dissection device yield different outcomes following bilateral skin-sparing mastectomy: a case report 
Although a skin- and nipple-sparing mastectomy technique offers distinct cosmetic and reconstructive advantages over traditional methods, partial skin flap and nipple necrosis remain a significant source of post-operative morbidity. Prior work has suggested that collateral thermal damage resulting from electrocautery use during skin flap development is a potential source of this complication. This report describes the case of a smoker with recurrent ductal carcinoma in situ (DCIS) who experienced significant unilateral skin necrosis following bilateral skin-sparing mastectomy while participating in a clinical trial examining mastectomy outcomes with two different surgical devices. This unexpected complication has implications for the choice of dissection devices in procedures requiring skin flap preservation.
Case presentation
The patient was a 61-year-old Caucasian woman who was a smoker with recurrent DCIS of her right breast. As part of the clinical trial, each breast was randomized to either the standard of care treatment group (a scalpel and a traditional electrosurgical device) or treatment with a novel, low thermal injury dissection device, allowing for a direct, internally controlled comparison of surgical outcomes. Post-operative follow-up at six days was unremarkable for both operative sites. At 16 days post-surgery, the patient presented with a significant wound necrosis in the mastectomy site randomized to the control study group. Following debridement and closure, this site progressively healed over 10 weeks. The contralateral mastectomy, randomized to the alternative device, healed normally.
We hypothesize that thermal damage to the subcutaneous microvasculature during flap dissection may have contributed to this complication and that the use of a low thermal injury dissection device may be advantageous in select patients undergoing skin- and nipple-sparing mastectomy.
PMCID: PMC3118368  PMID: 21619665
18.  The Use of Harmonic Scalpel for Free Flap Dissection in Head and Neck Reconstructive Surgery 
Plastic Surgery International  2012;2012:302921.
Surgeons conventionally use electrocautery dissection and surgical clip appliers to harvest free flaps. The ultrasonic Harmonic Scalpel is a new surgical instrument that provides high-quality dissection and hemostasis and minimizes tissue injury. The aim of this study was to evaluate the effectiveness and advantages of the ultrasonic Harmonic Scalpel compared to conventional surgical instruments in free flap surgery. This prospective study included 20 patients who underwent head and neck reconstructive surgery between March 2009 and May 2010. A forearm free flap was used for reconstruction in 12 patients, and a fibular flap was used in 8 patients. In half of the patients, electrocautery and surgical clips were used for free flap harvesting (the EC group), and in the other half of the patients, ultrasonic dissection was performed using the Harmonic Scalpel (the HS group). The following parameters were significantly lower in the HS group compared to the EC group: the operative time of flap dissection (35% lower in the HS group), blood loss, number of surgical clips and cost of surgical materials. This study demonstrated the effectiveness of the Harmonic Scalpel in forearm and fibular free flap dissections that may be extended to other free flaps.
PMCID: PMC3363368  PMID: 22693666
19.  Ultrasonically activated scalpel versus monopolar electrocautery shovel in laparoscopic total mesorectal excision for rectal cancer 
AIM: To investigate the feasibility and safety of monopolar electrocautery shovel (ES) in laparoscopic total mesorectal excision (TME) with anal sphincter preservation for rectal cancer in order to reduce the cost of the laparoscopic operation, and to compare ES with the ultrasonically activated scalpel (US).
METHODS: Forty patients with rectal cancer, who underwent laparoscopic TME with anal sphincter preservation from June 2005 to June 2007, were randomly divided into ultrasonic scalpel group and monopolar ES group, prospectively. White blood cells (WBC) were measured before and after operation, operative time, blood loss, pelvic volume of drainage, time of anal exhaust, visual analogue scales (VAS) and surgery-related complications were recorded.
RESULTS: All the operations were successful; no one was converted to open procedure. No significant differences were observed in terms of preoperative and postoperative d 1 and d 3 WBC counts (P = 0.493, P = 0.375, P = 0.559), operation time (P = 0.235), blood loss (P = 0.296), anal exhaust time (P = 0.431), pelvic drainage volume and VAS in postoperative d 1 (P = 0.431, P = 0.426) and d 3 (P = 0.844, P = 0.617) between ES group and US group. The occurrence of surgery-related complications such as anastomotic leakage and wound infection was the same in the two groups.
CONCLUSION: ES is a safe and feasible tool as same as US used in laparoscopic TME with anal sphincter preservation for rectal cancer on the basis of the skillful laparoscopic technique and the complete understanding of laparoscopic pelvic anatomy. Application of ES can not only reduce the operation costs but also benefit the popularization of laparoscopic operation for rectal cancer patients.
PMCID: PMC2725347  PMID: 18609692
Laparoscopy; Ultrasonically activated scalpel; Monopolar electrocautery; Rectal cancer; Total mesorectal excision
20.  Ventricular fibrillation caused by electrocoagulation in monopolar mode during laparoscopic subphrenic mass resection 
Surgical Endoscopy  2010;25(1):309-311.
Monopolar is usually a safe and effective electrosurgical unit used in laparoscopic general surgery. However, it can cause adverse outcomes and even cardiac arrest. We present a video of laparoscopic subphrenic mass resection using monopolar coagulation during which ventricular fibrillation occurred and from which the patient was successfully resuscitated.
Our patient was a 39-year-old man who was admitted to our institution for treatment of a liver mass. The mass was located in the left subphrenic region and was 3.31 cm × 2.7 cm according to B ultrasound. He had had a spleen resection after a car accident 14 years before. He was otherwise healthy and a physical examination was negative. He was scheduled for “laparoscopic exploration, mass resection.” General anesthesia was induced and the operation began. While dissecting the mass from the diaphragm there was some bleeding; monopolar electrocoagulation with 68 W was performed upon which ventricular fibrillation occurred. The operation was stopped and closed-chest compression began immediately. Defibrillation (200-J shock) was performed in 1 min and rhythm returned to sinus.
The operation was resumed carefully and uneventfully. The patient was sent to the postoperative acute care unit and was extubated 10 min after operation. The patient recovered uneventfully without any signs of permanent cardiac injury and was discharged on postoperative day 3. The final pathology was accessory spleen.
We present a video of a patient who experienced ventricular fibrillation during laparoscopic surgery which was successfully defibrillated leaving no permanent cardiac injury. We assume the reason for the ventricular fibrillation was the low-frequency leakage current from electrocoagulation which may be conducted by Swan-Ganz catheter to the heart. It is important that we be familiar with the character of electrosurgical unit when performing laparoscopic surgery. We should be careful when using an electrosurgical unit near the cardiac region, especially when the patient has an indwelling catheter. We recommend performing hemostasis in bipolar mode or use an ultrasonic scalpel if bleeding is close to the heart. Also, an easily available defibrillator should be ready for use.
Electronic supplementary material
The online version of this article (doi:10.1007/s00464-010-1157-0) contains supplementary material, which is available to authorized users.
PMCID: PMC3003788  PMID: 20589512
Laparoscopic surgery; Ventricular fibrillation; Electrocautery; Monopolar mode
21.  Comparison of Wet Radiofrequency Ablation with Dry Radiofrequency Ablation and Radiofrequency Ablation Using Hypertonic Saline Preinjection: Ex Vivo Bovine Liver 
Korean Journal of Radiology  2004;5(4):258-265.
We wished to compare the in-vitro efficiency of wet radiofrequency (RF) ablation with the efficiency of dry RF ablation and RF ablation with preinjection of NaCl solutions using excised bovine liver.
Materials and Methods
Radiofrequency was applied to excised bovine livers in a monopolar mode for 10 minutes using a 200 W generator and a perfused-cooled electrode with or without injection or slow infusion of NaCl solutions. After placing the perfused-cooled electrode in the explanted liver, 50 ablation zones were created with five different regimens: group A; standard dry RF ablation, group B; RF ablation with 11 mL of 5% NaCl solution preinjection, group C; RF ablation with infusion of 11 mL of 5% NaCl solution at a rate of 1 mL/min, group D; RFA with 6 mL of 36% NaCl solution preinjection, group E; RF ablation with infusion of 6 mL of 36% NaCl solution at a rate of 0.5 mL/min. In groups C and E, infusion of the NaCl solutions was started 1 min before RF ablation and then maintained during RF ablation (wet RF ablation). During RF ablation, we measured the tissue temperature at 15 mm from the electrode. The dimensions of the ablation zones and changes in impedance, current and liver temperature during RF ablation were then compared between the groups.
With injection or infusion of NaCl solutions, the mean initial tissue impedance prior to RF ablation was significantly less in groups B, C, D, and E (43-75 Ω) than for group A (80 Ω) (p < 0.05). During RF ablation, the tissue impedance was well controlled in groups C and E, but it was often rapidly increased to more than 200 Ω in groups A and B. In group D, the impedance was well controlled in six of ten trials but it was increased in four trials (40%) 7 min after starting RF ablation. As consequences, the mean current was higher for groups C, D, and E than for the other groups: 401 ± 145 mA in group A, 287 ± 32 mA in group B, 1907 ± 96 mA in group C, 1649 ± 514 mA in group D, and 1968 ± 108 mA in group E (p < 0.05). In addition, the volumes of RF-induced coagulation necrosis were greater in groups C and E than in group D, which was greater than in groups A and B than in group E (p < 0.05); 14.3 ± 3.0 cm3 in group A; 12.4 ± 3.8 cm3 in group B; 80.9 ± 9.9 cm3 in group C; 45.3 ± 11.3 cm3 in group D and 81.6 ± 8.6 cm3 in group E. The tissue temperature measured at 15 mm from the electrode was higher in groups C, D and E than other groups (p < 0.05): 53 ± 12℃ in group A, 42 ± 2℃ in group B, 93 ± 8℃ in group C; 79 ± 12℃ in group D and 83 ± 8℃ in group E.
Wet RF ablation with 5% or 36% NaCl solutions shows better efficiency in creating a large ablation zone than does dry RF ablation or RF ablation with preinjection of NaCl solutions.
PMCID: PMC2698170  PMID: 15637476
Experimental study; Interventional procedures; Liver; Radiofrequency ablation
22.  Comparison of Ultrasonic Scalpel versus Conventional Techniques in Open Gastrectomy for Gastric Carcinoma Patients: A Systematic Review and Meta-Analysis 
PLoS ONE  2014;9(7):e103330.
To compare surgical efficacy and postoperative recovery of ultrasonic scalpel (USS) with conventional techniques for the resection of gastric carcinoma.
A systematic search of major medical databases (PubMed, Embase, CCRT and CNKI) was conducted. Both randomized and non-randomized controlled trials (RCTs and nRCTs) were considered eligible. Operation time (OT), intraoperative blood loss (BL) and postoperative complications (POC) rates as well as postoperative hospitalization days, number of dissected lymph nodes, abdominal drainage volume and time for recovery of gastrointestinal functions were synthesized and compared.
Nineteen studies were included (7 RCTs and 12 nRCTs), in which 1930 patients were enrolled totally (946 in the USS group and 984 in the conventional group). Monopolar electrocautery and ligation were used as the conventional methods. Comparative meta-analysis showed perioperative outcomes were significantly improved using USS compared with conventional surgical instrumentation. OT was reduced from a weighted mean of 185.3 min in the conventional group to 151.0 min in the USS group (MD = −33.30, 95% CI [−41.75, −24.86], p<0.001) and intraoperative BL was decreased from a weighted mean of 217.9 ml in the conventional group to 111.6 ml in the USS group (MD = −113.42, 95% CI [−142.05, −84.79], p<0.001). Results from RCTs subgroup were consistent with those from nRCTs subgroup. The weighted cumulative risk of POC accounted for 8.9% (0%–25%) and 12.9% (5.5%–45%) in the USS and conventional groups, respectively. Pooled estimated results from nRCTs (OR = 0.54, 95% CI [0.27, 1.06], p = 0.07) and RCTs (RR = 0.75, 95% CI [0.44, 1.26], p = 0.27) showed no significant difference between the USS and control groups. Analysis of secondary outcomes showed the improvements of the USS group over control group regarding the number of dissected lymph nodes, postoperative hospitalization days, abdominal drainage volume and time for recovery of gastrointestinal functions.
Compared with conventional electrosurgery, the USS is a safe and effective technique with more short-term advantages in open surgery for gastric cancer.
PMCID: PMC4117513  PMID: 25079780
23.  Laparoscopic “Dome-Down” Cholecystectomy With the LCS-5 Harmonic Scalpel 
Misidentification of ductal anatomy and electrocautery injuries are complications associated with laparoscopic cholecystectomy (LC). Dome-down LC creates a 360-degree view of the gallbladder-cystic duct junction, reducing the risk for anatomy misidentification. In addition, ultrasonic instrumentation eliminates the risk for electrocautery injuries. This study assessed the feasibility and safety of dome-down LC combined with ultrasound technology.
Patients with noncancerous gallbladder disease were enrolled consecutively. Gallbladders were classified by clarity (Class I to IV) of anatomy and pathology (acute, chronic, or acalculous). The gallbladder was dissected from the gallbladder bed using a dome-down technique, and the cystic artery was coagulated and transected with the LCS-5 Harmonic scalpel (Ethicon Endo-Surgery Inc., Cincinnati, Ohio). The cystic duct was ligated with 2-polydioxanone Endoloops size 2– 0 and sharply divided, leaving one Endoloop on the cystic duct stump.
LC was successfully completed in 105 patients (mean age, 44 years; range, 18 to 91 years) in whom the anatomy was classified as Class I in 30 (29%) patients, Class II in 42 (38%), Class III in 25 (24%), and Class IV in 8 (8%). Gallbladder dissection time ranged from 8 to 42 minutes (mean, 18 min). The operating room time ranged from 32 to 128 minutes (mean, 55 min). Two gallbladder perforations occurred, but no complications were associated with the extrahepatic biliary tree, viscera, or major blood vessels. Elective conversion occurred in 8 (7.6%) patients due to poor visualization of anatomy because of inflammation and adhesions. Patient blood loss was minimal in all cases. No postoperative complications were observed after a 6-month follow-up.
Dome-down laparoscopic cholecystectomy with the LCS-5 Harmonic scalpel decreases the potential for misidentification of ductal anatomy, has minimal complications, and eliminates electrocautery risks. Conversion is related to poor visualization of anatomy due to inflammation and adhesions.
PMCID: PMC3015565  PMID: 15791971
Laparoscopy; Dome-down; Cholecystectomy; Laparoscopic coagulating shears; Ultrasound
24.  An Electrode Array for Limiting Blood Loss During Liver Resection: Optimization via Mathematical Modeling 
Liver resection is the current standard treatment for patients with both primary and metastatic liver cancer. The principal causes of morbidity and mortality after liver resection are related to blood loss (typically between 0.5 and 1 L), especially in cases where transfusion is required. Blood transfusions have been correlated with decreased long-term survival, increased risk of perioperative mortality and complications. The goal of this study was to evaluate different designs of a radiofrequency (RF) electrode array for use during liver resection. The purpose of this electrode array is to coagulate a slice of tissue including large vessels before resecting along that plane, thereby significantly reducing blood loss. Finite Element Method models were created to evaluate monopolar and bipolar power application, needle and blade shaped electrodes, as well as different electrode distances. Electric current density, temperature distribution, and coagulation zone sizes were measured. The best performance was achieved with a design of blade shaped electrodes (5 × 0.1 mm cross section) spaced 1.5 cm apart. The electrodes have power applied in bipolar mode to two adjacent electrodes, then switched sequentially in short intervals between electrode pairs to rapidly heat the tissue slice. This device produces a ~1.5 cm wide coagulation zone, with temperatures over 97 ºC throughout the tissue slice within 3 min, and may facilitate coagulation of large vessels.
PMCID: PMC2840609  PMID: 20309395
25.  The tissue effect of argon-plasma coagulation with prior submucosal injection (Hybrid-APC) versus standard APC: A randomized ex-vivo study 
Thermal ablation for Barrett’s oesophagus has widely been established in gastrointestinal endoscopy during the last decade. The mainly used methods of radiofrequency ablation (RFA) and argon-plasma coagulation (APC) carry a relevant risk of stricture formation of up to 5–15%. Newer ablation techniques that are able to overcome this disadvantage would therefore be desirable. The aim of the present study was to compare the depth of tissue injury of the new method of Hybrid-APC versus standard APC within a randomized study in a porcine oesophagus model.
Using a total of eight explanted pig oesophagi, 48 oesophageal areas were ablated either by standard or Hybrid-APC (APC with prior submucosal fluid injection) using power settings of 50 and 70 W. The depth of tissue injury to the oesophageal wall was analysed macroscopically and histopathologically.
Using 50 W, mean coagulation depth was 937 ± 469 µm during standard APC, and 477 ± 271 µm during Hybrid-APC (p = 0.064). Using 70 W, coagulation depth was 1096 ± 320 µm (standard APC) and 468 ± 136 µm (Hybrid-APC; p = 0.003). During all settings, damage to the muscularis mucosae was observed. Using standard APC, damage to the submucosal layer was observed in 4/6 (50 W) and 6/6 cases (70 W). During Hybrid-APC, coagulation of the submucosal layer occurred in 2/6 (50 W) and 1/6 cases (70 W). The proper muscle layer was only damaged during conventional APC (50 W: 1/6; 70 W: 3/6).
Ex-vivo animal study with limited number of cases.
Hybrid-APC reduces coagulation depth by half in comparison with standard APC, with no thermal injury to the proper muscle layer. It may therefore lead to a lower rate of stricture formation during clinical application.
PMCID: PMC4212496  PMID: 25360316
Argon-plasma coagulation; Hybrid-APC; standard APC; submucosal injection

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