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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.  The effects of scalpel, harmonic scalpel and monopolar electrocautery on the healing of colonic anastomosis after colonic resection 
In our study, the effects of harmonic scalpel, scalpel, and monopolar electrocautery usage on the health and healing of colon anastomosis after resection was investigated.
In this study, 120 female albino Wistar rats were divided into 3 groups each containing 40 rats. Group A, resection with scalpel; group B, resection with monopolar electrocautery; group C, resection with harmonic scalpel. The groups were divided into 4 subgroups consisting of 10 rats and analysed in the postoperative 1st, 3rd, 5th, and 7th days. Anastomotic bursting pressures, hydroxyproline levels and histopathological parameters were surrogate parameters for evaluating wound healing.
The tissue hydroxyproline levels did not show any significant difference between the groups and subgroups. The mean bursting pressure of group A on the 5th day was significantly higher than groups B and C (P < 0.001). When the fibroblast and fibrosis scores were evaluated, scores of group C on the 5th day were significantly higher than the other groups, but the results of bursting pressures and biochemical parameters did not support the fibroblast and fibrosis scores. There were not any significant differences between the groups in other histopathologic parameters.
The use of monopolar electrocautery needs more attention since the device causes tissue destruction. The obliterating effect of harmonic scalpel on luminal organs is an important problem, especially if an anastomosis is planned. Despite the disadvantages of scalpel, its efficacy on early wound healing is better than the other devices.
PMCID: PMC4891522  PMID: 27274507
Electrosurgery; Surgical anastomosis; Colon; Anastomosis healing
6.  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
7.  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
8.  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
9.  The comparison of thermal tissue injuries caused by ultrasonic scalpel and electrocautery use in rabbit tongue tissue 
The aim of this study compares to the increase in tissue temperature and the thermal histological effects of ultrasonic scalpel, bipolar and unipolar electrosurgery incisions in the tongue tissue of rabbits. This study evaluates the histopathological changes related to thermal change and the maximum temperature values in the peripheral tissue brought about by the incisions carried out by the three methods in a comparative way. To assess thermal tissue damage induced by the three instruments, maximum tissue temperatures were measured during the surgical procedure and tongue tissue samples were examined histopathologically following the surgery. The mean maximum temperature values of the groups were 93.93±2.76 C° for the unipolar electrocautery group, whereas 85.07±5.95 C° for the bipolar electrocautery group, and 108.23±7.64 C° for the ultrasonic scalpel group.
There was a statistically significant relationship between the increase in maximum temperature values and the separation among tissue layers, edema, congestion, necrosis, hemorrhage, destruction in blood vessel walls and fibrin accumulation, and between the existence of fibrin thrombus and tissue damage depth (p<0.05).
It was concluded that the bipolar electrocautery use gives way to less temperature increase in the tissues and less thermal tissue damage in comparison to the other methods.
PMCID: PMC4362423  PMID: 22938541
Rabbit; tongue; electrocautery; scalpel; temperature; thermal injury
10.  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  PMID: 25674380
11.  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
12.  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
13.  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
14.  Diode Laser Excision of Oral Benign Lesions 
Introduction: Lasers have made tremendous progress in the field of dentistry and have turned out to be crucial in oral surgery as collateral approach for soft tissue surgery. This rapid progress can be attributed to the fact that lasers allow efficient execution of soft tissue procedures with excellent hemostasis and field visibility. When matched to scalpel, electrocautery or high frequency devices, lasers offer maximum postoperative patient comfort.
Methods: Four patients agreed to undergo surgical removal of benign lesions of the oral cavity. 810 nm diode lasers were used in continuous wave mode for excisional biopsy. The specimens were sent for histopathological examination and patients were assessed on intraoperative and postoperative complications.
Results: Diode laser surgery was rapid, bloodless and well accepted by patients and led to complete resolution of the lesions. The excised specimen proved adequate for histopathological examination. Hemostasis was achieved immediately after the procedure with minimal postoperative problems, discomfort and scarring.
Conclusion: We conclude that diode lasers are rapidly becoming the standard of care in contemporary dental practice and can be employed in procedures requiring excisional biopsy of oral soft tissue lesions with minimal problems in histopathological diagnosis.
PMCID: PMC4599200  PMID: 26464781
Diode laser; Biopsy; Soft tissue
15.  Comparison of a Hemorrhoidectomy With Ultrasonic Scalpel Versus a Conventional Hemorrhoidectomy 
Annals of Coloproctology  2016;32(3):111-116.
A variety of instruments, including circular staplers, ultrasonic scalpels, lasers, and bipolar electrothermal devices, are currently used when performing a hemorrhoidectomy. This study compared outcomes between hemorrhoidectomies performed with an ultrasonic scalpel and conventional methods.
The study was a randomized prospective review of data available between May 2013 and December 2013, involving 50 patients who had undergone a hemorrhoidectomy for grade III or IV internal hemorrhoids. The hemorrhoidal pedicle was coagulated with an ultrasonic device in the ultrasonic scalpel group (n = 25) and sutured with 3-0 vicryl material after excision in the conventional method group (n = 25).
The patients' demographics, clinical characteristics, and lengths of hospital stay were similar in both groups. The mean ages of the conventional and the ultrasonic scalpel groups were, respectively, 20.8 ± 1.6 and 22.4 ± 5.0 years (P = 0.240). In comparison with the conventional method group, the ultrasonic scalpel group had a shorter operation time (P < 0.005), less postoperative pain on the visual analogue scale score (for example, P = 0.211 on postoperative day 1), and less postoperative bleeding (P = 0.034). No significant differences in postoperative complications were observed between the 2 groups.
A hemorrhoidectomy using an ultrasonic scalpel is an effective and safe procedure. The ultrasonic scalpel reduces the operation time, the postoperative blood loss, and the postoperative pain. Long-term follow-up with larger-scale studies is required to evaluate normal activity after a hemorrhoidectomy performed with an ultrasonic scalpel.
PMCID: PMC4942526  PMID: 27437393
Hemorrhoidectomy; Ultrasonic scalpel; Conventional method
16.  Deep Bleeder Acoustic Coagulation (DBAC)—part II: in vivo testing of a research prototype system 
Deep Bleeder Acoustic Coagulation (DBAC) is an ultrasound image-guided high-intensity focused ultrasound (HIFU) method proposed to automatically detect and localize (D&L) and treat deep, bleeding, combat wounds in the limbs of soldiers. A prototype DBAC system consisting of an applicator and control unit was developed for testing on animals. To enhance control, and thus safety, of the ultimate human DBAC autonomous product system, a thermal coagulation strategy that minimized cavitation, boiling, and non-linear behaviors was used.
Material and methods
The in vivo DBAC applicator design had four therapy tiles (Tx) and two 3D (volume) imaging probes (Ix) and was configured to be compatible with a porcine limb bleeder model developed in this research. The DBAC applicator was evaluated under quantitative test conditions (e.g., bleeder depths, flow rates, treatment time limits, and dose exposure time limits) in an in vivo study (final exam) comprising 12 bleeder treatments in three swine. To quantify blood flow rates, the “bleeder” targets were intact arterial branches, i.e., the superficial femoral artery (SFA) and a deep femoral artery (DFA). D&L identified, characterized, and targeted bleeders. The therapy sequence selected Tx arrays and determined the acoustic power and Tx beam steering, focus, and scan patterns. The user interface commands consisted of two buttons: “Start D&L” and “Start Therapy.” Targeting accuracy was assessed by necropsy and histologic exams and efficacy (vessel coagulative occlusion) by angiography and histology.
The D&L process (Part I article, J Ther Ultrasound, 2015 (this issue)) executed fully in all cases in under 5 min and targeting evaluation showed 11 of 12 thermal lesions centered on the correct vessel subsection, with minimal damage to adjacent structures. The automated therapy sequence also executed properly, with select manual steps. Because the dose exposure time limit (tdose ≤ 30 s) was associated with nonefficacious treatment, 60-s dosing and dual-dosing was also pursued. Thrombogenic evidence (blood clotting) and collagen denaturation (vessel shrinkage) were found in necropsy and histologically in all targeted SFAs. Acute SFA reductions in blood flow (20–30 %) were achieved in one subject, and one partial and one complete vessel occlusion were confirmed angiographically. The complete occlusion case was achieved with a dual dose (90 s total exposure) with focal intensity ≈500 W/cm2 (spatial average, temporal average).
While not meeting all in vivo objectives, the overall performance of the DBAC applicator was positive. In particular, D&L automation workflow was verified during each of the tests, with processing times well under specified (10 min) limits, and all bleeder branches were detected and localized. Further, gross necropsy and tissue examination confirmed that the HIFU thermal lesions were coincident with the target vessel locations in over 90 % of the multi-array dosing treatments. The SFA/DFA bleeder models selected, and the protocols used, were the most suitable practical model options for the given DBAC anatomical and bleeder requirements. The animal models were imperfect in some challenging aspects, including requiring tissue-mimicking material (TMM) standoffs to achieve deep target depths, thereby introducing device-tissue motion, with resultant imaging artifacts. The model “bleeders” involved intact vessels, which are subject to less efficient heating and coagulation cascade behaviors than true puncture injuries.
PMCID: PMC4582735  PMID: 26413296
17.  Diathermy versus Scalpel Incision in a Heterogeneous Cohort of General Surgery Patients in a Nigerian Teaching Hospital 
The anecdotal fear of using cautery for surgical incisions is still common in surgical practice despite recent evidences. The aim of this study is to compare the results of electrocautery and the scalpel in skin incisions.
Materials and Methods:
This is a prospective randomized double blind study conducted in the Department of Surgery, of a teaching hospital in Ibadan. Patients were randomized to have either scalpel or electrocautery incisions. The duration used in making the skin incision; the incisional blood loss and the ensuing length and depth of the wound were noted. Postoperative pain; duration of wound healing and the occurrence of surgical site infection were also noted.
There were 197 patients consisting of the scalpel group (n = 98) and the electrocautery group (n = 99). The ages ranged from 16 to 73 years. The demography, case distribution and body mass index were similar in both groups. The mode of presentation was predominantly elective. The incision time was shorter in the electrocautery group (P < 0.001). The blood loss was less with the diathermy compared to the scalpel (6.53 ± 3.84 ml vs. 18.16 ± 7.36 ml, P < 0.001). The cumulative numerical rating scale score for pain was 12.65 (standard deviation [SD] 8.06) and 17.12 (SD 9.49) in the diathermy and scalpel groups respectively (P < 0.001). There was no statistically significant difference in wound infection and wound closure (epithelialization time) (P = 0.206).
The use of electrocautery in making skin incision is associated with reduced incision time, incisional blood loss, and postoperative pain.
PMCID: PMC4382642  PMID: 25838766
Diathermy; electrocautery; general surgery; surgical incision
18.  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
19.  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
20.  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
21.  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
22.  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
23.  Postoperative Adhesion Formation in a Rabbit Model: Monopolar Electrosurgery Versus Ultrasonic Scalpel 
Background and Objectives:
To determine if surgery using ultrasonic energy for dissection results in less adhesion formation than monopolar electrosurgical energy in the late (8 weeks) postoperative period.
Injuries were induced in rabbits by using ultrasonic energy on one uterine horn and the adjacent pelvic sidewall and using monopolar energy on the opposite side. Eight weeks postoperatively, the rabbits underwent autopsy and clinical and pathologic scoring of adhesions was performed by blinded investigators.
There was no significant difference in clinical adhesion scores between the two modalities. The mean clinical score for monopolar cautery was 1.00 versus 0.88 for the Harmonic device (Ethicon Endo-Surgery, Cincinnati, Ohio) (P = .71). Furthermore, there was no significant difference found in the pathologic adhesion scores between the ultrasonic scalpel and monopolar energy. The mean pathologic score for monopolar electrosurgery was 4.35 versus 3.65 for the Harmonic scalpel (P = .30).
Neither monopolar electrosurgery nor ultrasonic dissection is superior in the prevention of adhesion formation in the late postoperative period.
PMCID: PMC4432717  PMID: 26005316
Adhesions; Energy sources; Laparoscopy; Monopolar electrosurgery; Ultrasonic dissection
24.  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
25.  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

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