This experimental study verified the effect of adipose-tissue-derived stem cells (ASCs) on the healing of ischemic colonic anastomoses in rats.
ASCs were isolated from the subcutaneous fat tissue of rats and identified as mesenchymal stem cells by identification of different potentials. An animal model of colonic ischemic anastomosis was induced by modifying Nagahata's method. Sixty male Sprague-Dawley rats (10-week-old, 370 ± 50 g) were divided into two groups (n = 30 each): a control group in which the anastomosis was sutured in a single layer with 6-0 polypropylene without any treatment and an ASCtreated group (ASC group) in which the anastomosis was sutured as in the control group, but then ASCs were locally transplanted into the bowel wall around the anastomosis. The rats were sacrificed on postoperative day 7. Healing of the anastomoses was assessed by measuring loss of body weight, wound infection, anastomotic leakage, mortality, adhesion formation, ileus, anastomotic stricture, anastomotic bursting pressure, histopathological features, and microvascular density.
No differences in wound infection, anastomotic leakage, or mortality between the two groups were observed. The ASC group had significantly more favorable anastomotic healing, including less body weight lost, less ileus, and fewer ulcers and strictures, than the control group. ASCs augmented bursting pressure and collagen deposition. The histopathological features were significantly more favorable in the ASC group, and microvascular density was significantly higher than it was in the control group.
Locally-transplanted ASCs enhanced healing of ischemic colonic anastomoses by increasing angiogenesis. ASCs could be a novel strategy for accelerating healing of colonic ischemic risk anastomoses.
Colonic anastomosis; Ischemia; Anastomotic healing; Adipose-tissue-derived stem cell; Angiogenesis
Background: Polyglycolic acid mesh (PAM) reinforcement of colonic anastomoses were evaluated. Methods: Twenty female albino rabbits were divided into two groups. Each rabbit underwent segmental colonic resection with single-layer anastomosis. In one group of rabbits, PAM of length equal to the circumference of the anastomosis was applied. Rabbits were sacrificed on postoperative day 10 and peritoneal adhesions, anastomosis burst pressure, and anastomosis histopathological characteristics were evaluated. Results: The average burst pressure for the control and PAM groups was 149±15.95 mmHgand 224±124.5 mmHg, respectively (p=0.578). All control anastomoses burst, whereas only five (50%) PAM anastomoses burst (p<0.03). There was no anastomotic leakage in the control group, whereas three PAM group anastomoses leaked (p=0.210). The collagen fiber density and amount of neovascularization were lower in the PAM than the control group (p=0.001 and p=0.002, respectively). The average peritoneal adhesion value was 1.6±0.51 in the control group and 2.9±0.31 in the PAM group (p<0.0001). Conclusion: The new fixed PAM-reinforced anastomosis technique resulted in an increased risk of anastomosis leakage and peritoneal adhesion, but also higher in non-burst anastomoses.
Anastomosis; polyglycolic acid; colon; mesh; novel; technique
Enteroglucagon has been implicated as a tropic hormone in the control of intestinal adaptation. Because cells producing enteroglucagon are located mainly in the distal small bowel (and colon), ileal resection might be expected to produce less adaptive change than a jejunal resection of equivalent length. This hypothesis was tested in male Sprague-Dawley rats (n = 40) weighing 184.0 +/- 7.3 g and receiving a Thiry-Vella fistula (TVF) of the mid-60% of the small intestine. One group had concomitant resection of the jejunum proximal to the TVF (n = 12), another had resection of the ileum distal to the TVF (n = 13), while controls had a TVF alone (n = 15). When killed 10 days postoperatively rats with ileal resection weighed only 81% of controls (p less than 0.001) and 85% of those with jejunal resection (p less than 0.01). Jejunal resection produced an 81% increase in crypt cell production rate (measured by a stathmokinetic technique) over control values (28.5 +/- 4.2 v 15.8 +/- 2.3 cells/crypt/h: p = 0.025), whereas ileal resection had no demonstrable effect (17.5 +/- 2.3 cells/crypt/h). Adaptive hyperplasia in isolated small bowel is modulated by factors localised to the distal small intestine, enteroglucagon being a plausible candidate.
Ischemic preconditioning (IP) decreases severity of liver necrosis and has anti-apoptotic effects in previous studies using liver regeneration in normal rats. This study assessed the effect of IP on liver regeneration after hepatic resection in cirrhotic rats.
To induce liver cirrhosis, thioacetamide (300 mg/kg) was injected intraperitoneally into Sprague-Dawley rats twice per week for 16 weeks. Animals were divided into four groups: non-clamping (NC), total clamping (TC), IP, and intermittent clamping (IC). Ischemic injury was induced by clamping the left portal pedicle including the portal vein and hepatic artery. Liver enzymes alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured to assess liver damage. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining for apoptosis and proliferating cell nuclear antigen (PCNA) staining for cell replication were also performed.
Day-1 ALT and AST were highest in IP, however, levels in NC and IC were comparably low on days 1-7. There was no significant correlation of AST or ALT with experimental groups (P=0.615 and P=0.186). On TUNEL, numbers of apoptotic cells at 100× magnification (cells/field) were 31.8±24.2 in NC, 69.0±72.3 in TC, 80.2±63.1 in IP, and 21.2±20.8 in IC (P<0.05). When regeneration capacity was assessed by PCNA staining, PCNA-positive cells (cells/field) at 400× were 3.4±6.0 in NC, 16.9±69 in TC, 17.0±7.8 in IP and 7.4±7.6 in IC (P<0.05).
Although regeneration capacity in IP is higher than IC, the liver is vulnerable to ischemic damage in cirrhotic rats. Careful consideration is needed in applying IP in the clinical setting.
Liver cirrhosis; Ischemic preconditioning; Liver regeneration; Hepatectomy; Apoptosis
Several systemic factors, including jaundice, long-term corticosteroid therapy, diabetes and malnutrition, increase the risk of anastomotic dehiscence. The local application of molgramostim (recombinant human granulocyte-macrophage colony stimulating factor) has been reported to improve impaired dermal wound healing. Since jaundice, one of the systemic risk factors for anastomotic dehiscence, causes significant impairment of anastomotic healing, we hypothesized that locally injected molgramostim could improve the healing of bowel anastomoses in bile-duct-ligated rats used as an experimental model for jaundice.
Eighty-six Sprague–Dawley rats were randomized into 4 groups of 20–22 animals each as follows: group 1 — colonic anastomosis only; group 2 — laparotomy followed 7 days later by colonic anastomosis; group 3 — common-bile-duct ligation (CBDL) followed 7 days later by colonic anastomosis (control group); group 4 — CBDL followed by colonic anastomosis with locally applied molgramostim. Laparotomy was performed under anesthesia in group 2 rats. In groups 3 and 4, laparotomy was followed by ligation and dissection of the common bile duct. After 7 days, colonic anastomosis was performed; in group 4 rats, molgramostim (50 μg) was injected into the perianastomotic area. On postoperative day 3, rats were killed, and the bursting pressures and hydroxyproline levels measured. Two rats from each group were selected for histopathological examination.
The mean bursting pressure in group 4 was significantly higher than that in group 3 (37.8 v. 30.5 mm Hg [p < 0.01]). The mean hydroxyproline level in group 3 was significantly lower than that of the other groups (2.7 v. 3.1–3.5 mg/g tissue [p < 0.01]). On histopathological examination, specimens from group 4 rats showed an increased mononuclear cell population and a smaller gap on the anastomotic line than those from group 3.
The local injection of molgramostim improves healing of the impaired wound in rats subjected to CBDL.
Isotope liver scan, ultrasonography, and computed tomography of the liver were performed during the postoperative period in 43 consecutive patients undergoing laparotomy for colorectal carcinoma. Obvious hepatic metastases were detected in six patients at the time of surgery. Eleven patients considered to have a disease-free liver at laparotomy developed hepatic metastases during the two-year follow-up period. These patients were considered to have had occult hepatic metastases at the time of surgery. Postoperative isotope liver scan, ultrasonography, and computed tomography detected the presence of overt metastases in four, five, and six patients respectively. Of the 11 patients with occult metastases, isotope liver scan, ultrasonography, and computed tomography detected one, three, and nine respectively. These observations suggest that 29% of patients undergoing apparently curative resection for colorectal carcinoma possess occult hepatic metastases and that computed tomography is superior to ultrasonography and isotope liver scan in detecting them.
AIM: To evaluate the effect of propolis administration on the healing of colon anastomosis with light and transmission electron microscopes.
METHODS: Forty-eight Wistar-Albino female rats were divided into two groups and had colon resection and anastomosis. In group I, rats were fed with standard rat chow pre- and postoperatively. The rats in group II were fed with standard rat chow and began receiving oral supplementation of propolis 100 mg/kg per day beginning 7 d before the operation and continued until they were sacrificed. Rats were sacrificed 1, 3, 7 and 14 d after operation, and anastomotic bursting pressures measured. After the resection of anastomotic segments, histopathological examination was performed with light and transmission electron microscopes by two blinded histologists and photographed.
RESULTS: The colonic bursting pressures of the propolis group were statistically significantly better than the control group. Ultrastructural histopathological analysis of the colon anastomosis revealed that propolis accelerated the phases of the healing process and stimulated mature granulation tissue formation and collagen synthesis of fibroblasts.
CONCLUSION: Bursting pressure measurements and ultra structural histopathological evaluation showed that administration of propolis accelerated the healing of colon anastomosis following surgical excision.
Propolis; Wound healing; Colon anastomosis; Histopathology; Transmission electron microscope
A 39 year-old patient with cholangiocarcinoma and pre-existing ulcerative colitis was successfully treated by orthotopic liver transplantation. He was given low doses of prednisone and azathioprine and survived for more than 9 months, dying with tumour metastases, thrombosis of the inferior vena cava and an intra-abdominal abscess. At autopsy the homograft showed little evidence of rejection. Preoperatively the patient had septicemia. Removal of his liver was difficult. The discrepancy between donor and recipient in size of blood vessels and the presence of two hepatic arteries in the donor caused problems during the vascular anastomoses. During the operation cardiac arrest occurred. Postoperatively there were several medical and surgical problems, including intraperitoneal and gastrointestinal hemorrhage, paralysis of the right dome of the diaphragm, sinus bradycardia, massive diuresis, peroneal nerve palsy, and one major and three minor episodes of rejection, which were reversed by giving pulse doses of methylprednisolone intravenously.
Small-for-size syndrome (SFSS) is a major problem in liver surgery, and splenectomy has been used to prevent SFSS. However, it is unknown whether splenectomy has the same effect on liver regeneration in both standard and marginal hepatectomy. The aim of this study is to see a difference in effect of splenectomy on liver regeneration according to the amount of liver resection.
Thirty male Sprague-Dawley rats (220 to 260 g) were divided into the following five groups: control (n = 6), 70% hepatectomy (n = 6), 70% hepatectomy with splenectomy (n = 6), 90% hepatectomy (n = 6), and 90% hepatectomy with splenectomy (n = 6). The animals were euthanized 24 hours after surgery and liver specimens were obtained. To assess liver regeneration, we performed immunohistochemistry of liver tissue using 5-bromo-2-deoxyuridine (BrdU) labeling and Western blot analysis of hepatic growth factor (HGF) and transforming growth factor-β (TGF-β) in the liver tissue.
The splenectomized subgroup had a higher BrdU-positive cell count in the 90% hepatectomy group, but not in the 70% hepatectomy group (P < 0.001). Splenectomy significantly decreased TGF-β expression (P = 0.005) and increased the HGF to TGF-β ratio (P = 0.002) in the 90% hepatectomy group, but not in the 70% hepatectomy group.
The positive effect of splenectomy on liver regeneration was greater in the group with the larger liver resection. This phenomenon may be related to the relative balance between HGF and TGF-β in the liver.
Liver regeneration; Splenectomy; Hepatectomy; HGF; Transforming growth factor beta
Background: Hepatic adenosine triphosphate (ATP) levels are an accurate reflection of functioning hepatic mass following surgical resections and acute liver injury.
Objective: To determine whether hepatic ATP levels can serve as a non-invasive means of documenting progression of chronic liver disease to cirrhosis.
Methods: In vivo phosphorus-31 magnetic resonance spectroscopy (31P MRS) was performed in three animal models of chronic liver disease. Sixty six adult Sprague- Dawley rats were subjected to either thioacetamide, carbon tetrachloride (CCl4), or common bile duct ligation (CBDL) to induce liver disease (n=35, 21, and 10, respectively). Serial MRS examinations, blood samples, and liver biopsies (when appropriate) were obtained throughout and/or on completion of the study.
Results: Over the course of the chronic liver disease, a progressive decrease in hepatic ATP levels was consistently observed in each model. The findings were most striking when end stage liver disease (cirrhosis) was established. The reduction in hepatic ATP levels correlated with significant changes in serum albumin concentrations (CCl4 and CBDL models) and the extent of hepatocyte loss seen histologically (all models).
Conclusion: The results of this study indicate that during progression of chronic liver disease to cirrhosis, there is a progressive reduction in hepatic ATP levels. In addition, changes in hepatic ATP levels correlate with changes in liver function and histology. Thus hepatic 31P MRS provides a non-invasive means of documenting the severity and progression of parenchymal and cholestatic models of chronic liver disease in rats.
liver; magnetic resonance spectroscopy; liver disease; cirrhosis; rat
Objective: The Glissonean pedicle transection method of liver resection has been found to shorten operative time and minimize intraoperative bleeding during liver segmentectomy. We have compared the feasibility, effectiveness, and safety of the Glissonean pedicle transection method with the Pringle maneuver in patients undergoing selective curative resection of large hepatocellualr carcinoma (HCC).
Methods: Eligible patients with large (> 5 cm) nodular HCC (n = 50) were assigned to undergo curative hepatectomy using the Glissonean pedicle transection method (n = 25) or the Pringle maneuver (n = 25). Partial interruption of the infrahepatic inferior vena cava was incorporated to further reduce bleeding from liver transection. The primary outcome measure was postoperative changes in liver function from baseline. Secondary outcomes included operating time, volume of intraoperative blood loss/transfusion, and time to resolution of ascites.
Results: The two groups were comparable in age, sex, site and size of the liver tumor, segment or lobe intended to be resected, and liver function reserve, and the results were not significant statistically. All patients underwent successful major hepatectomies using the assigned method, with the extent of major hepatectomy comparable in the two groups (P = 0.832). The Glissonean approach was associated with shorter hepatic inflow interruption (30.0 ± 12.0 min vs. 45.0 ± 13.0 min, P < 0.001), lower volume of blood loss (145.0 ± 20.0 mL vs. 298.0 ± 109.0 mL, P < 0.001), reduced requirement for transfusion (0.0 ± 0.0 mL vs. 200.0 ± 109.0 mL, P < 0.0001), and more rapid resolution of ascites (9.5 ± 1.2 d vs. 15.3 ± 2.4 d, P < 0.001). Postoperative liver function measures were comparable in the two groups, and the results were not significant statistically.
Conclusion: The Glissonean pedicle transection method is a feasible, effective, and safe technique for hepatic inflow control during the curative resection of large nodular HCCs.
Hepatocellualr carcinoma, large nodular; Pringle maneuver; Glissonean pedicel transection; Partial interruption of inferior vena cava; Surgical outcomes.
The myofibroblasts play a central role in wound healing throughout the body. The process of wound healing in the colon was evaluated with emphasis on the role of myofibroblasts.
One hundred male Wistar rats weighing 274 ± 9.1 g (mean age: 3.5 months) were used. A left colonic segment was transected and the colon was re-anastomosed. Animals were randomly divided into two groups. The first group experimental animals (n = 50) were sacrificed on postoperative day 3, while the second group rats (n = 50) were sacrificed on postoperative day 7. Healing of colonic anastomosis was studied in terms of anastomotic bursting pressure, as well as myofibroblastic reaction and expression of α-smooth muscle actin (α-SMA), adhesion formation, inflammatory reaction and neovascularization.
The mean anastomotic bursting pressure increased from 20.6 ± 3.5 mmHg on the 3rd postoperative day to 148.8 ± 9.6 Hg on the 7th postoperative day. Adhesion formation was increased on the 7th day, as compared to the 3rd day. In addition, the myofibroblastic reaction was more profound on the 7th postoperative day in comparison with the 3rd postoperative day. The staining intensity for α-SMA was progressive from the 3rd to the 7th postoperative day. On the 7th day the α-SMA staining in the myofibroblats reached the level of muscular layer cells.
Our study emphasizes the pivotal role of myofibroblasts in the process of colonic anastomosis healing. The findings provide an explanation for the reduction in the incidence of wound dehiscence after the 7th postoperative day.
Different approaches to study liver regeneration in murine models have been proposed. We investigated the effect of different liver resection models on liver damage and regeneration parameters in mice.
We compared the technical aspect of the 2 most commonly used techniques of 50% and 70% liver resection. Liver damage, as determined by the change in serum alanine aminotransferase and aspartate aminotransferase, as well as the regeneration parameters VEGF and FGF-2 were analyzed at 6 time points. A postoperative vitality score was introduced.
Cholestasis was not observed for either technique. Both resection techniques resulted in full weight recovery of the liver after 240 hours, with no significant difference between sham and resection groups. Postoperative animal morbidity and total protein levels did not differ significantly for either method, indicating early and full functional recovery. However, comparing the mitogenic growth factors FGF-2 and VEGF, a significant increase in serum levels and, therefore, increased growth stimulus, was shown in the extended resection group.
Extended resection led to a greater response in growth factor expression. This finding is important since it shows that growth factor response differs acdording to the extent of resection. We have demonstrated the need to standardize murine hepatic resection models to adequately compare the resulting liver damage.
INTRODUCTION: Hepatic resection is an established modality of treatment for colorectal cancer metastases. Resection of breast cancer liver metastases remains controversial, but has been shown to be an effective treatment in selected cases. This study reports the outcome of 8 patients with liver metastases from breast cancer. PATIENTS & METHODS: 8 patients with liver metastases from previously treated breast cancer were referred for hepatic resection between September 1996 and December 2002. Six were eligible for liver resection. The mean age was 45.8 years. The resections performed included 1 segmentectomy and 5 hemihepatectomies of which one was an extended hemihepatectomy. One patient had a repeat hepatectomy 44 months after the first resection. RESULTS: There were no postoperative deaths or major morbidity. The resectability rate was 75%. Follow-up periods range from 6 to 70 months with a median survival of 31 months following resection. There have been 2 deaths, one died of recurrence in the residual liver at 6 months and one died disease-free from a stroke. Of the remaining 4 patients, 1 has had a further liver resection at 44 months following which she is alive and 'disease-free' at 70 months. The one patient with peritoneal recurrence is alive 49 months after her liver resection with 2 patients remaining disease-free. CONCLUSION: Hepatic resection for breast cancer liver metastases is a safe procedure with low morbidity and mortality.
AIM: To evaluate the results of hepatic resection with ex-situ hypothermic perfusion and without veno-venous bypass.
METHODS: In 3 patients with liver tumor, the degree of the inferior vena cava and/or main hepatic vein involvement was verified when the liver was dissociated in the operation. It was impossible to resect the tumors by the routine hepatectomy, so the patients underwent ex-situ liver surgery, vein cava replacement and hepatic autotransplantation without veno-venous bypass. All surgical procedures were carried out or supervised by a senior surgeon. A retrospective analysis was performed for the prospectively collected data from patients with liver tumor undergoing ex-situ liver surgery, vein cava replacement and hepatic autotransplantation without veno-venous bypass. We also compared our data with the 9 cases of Pichlmayr’s group.
RESULTS: Three patients with liver tumor were analysed. The first case was a 60-year-old female with a huge haemangioma located in S1, S4, S5, S6, S7 and S8 of liver; the second was a 64-year-old man with cholangiocarcinoma in S1, S2, S3 and S4 and the third one was a 55-year-old man with a huge cholangiocarcinoma in S1, S5, S7 and S8. The operation time for the three patients were 6.6, 6.4 and 7.3 h, respectively. The anhepatic phases were 3.8, 2.8 and 4.0 h. The volume of blood loss during operation were 1200, 3100, 2000 mL in the three patients, respectively. The survival periods without recurrence were 22 and 17 mo in the first two cases. As for the third case complicated with postoperative hepatic vein outflow obstruction, emergency hepatic vein outflow extending operation and assistant living donor liver transplantation were performed the next day, and finally died of liver and renal failure on the third day. Operation time (6.7 ± 0.47 h vs 13.7 ± 2.6 h) and anhepatic phase (3.5 ± 0.64 h vs 5.7 ± 1.7 h) were compared between Pichlmayr’s group and our series (P = 0.78).
CONCLUSION: Ex-situ liver resection and liver autotransplantation has shown a potential for treatment of complicated hepatic neoplasms that are unresectable by traditional procedures.
Liver autotransplantation; Ex-situ resection; Total vascular exclusion; Liver tumor
The continuing search for effective adjuvant therapy after resection of intestinal malignancies has prompted a growing interest in both immediate post-operative regional chemotherapy and the combination of 5-fluorouracil (5-FU) and interferon-alpha as drugs of choice. We have compared the effects of both compounds, alone and together, on early healing of intestinal anastomoses. Four groups (n = 26 each) of rats underwent resection and anastomosis of both ileum and colon: a control group and three groups receiving intraperitoneal 5-FU, interferon-alpha or both on the day of surgery and the next 2 days. Animals were killed 3 or 7 days (n = 10 each) after operation in order to measure anastomotic strength and hydroxyproline content. The remaining six animals in each group were used to study anastomotic collagen synthetic capacity at day 3. Three days after operation, ileal anastomotic bursting pressure was lowered by 37% in the 5-FU/interferon-alpha group (P = 0.0104). At day 7, anastomotic breaking strength was reduced significantly in ileum (P = 0.0221) and colon (P = 0.0054) of the 5-FU/interferon-alpha group and in colon of the interferon-alpha group (P = 0.0221). Collagen synthetic capacity was strongly suppressed by 5-FU but not by interferon-alpha. However, no differences in anastomotic hydroxyproline content were observed between groups at both days 3 and 7. Thus, post-operative use of interferon-alpha, in particular in combination with 5-FU, may be detrimental to anastomotic repair in the intestine.
Fifty consecutive patients with colorectal cancer but no evidence of secondary deposits in the liver were included in an ongoing controlled clinical trial of adjuvant liver perfusion aimed at reducing the incidence of hepatic metastases. All patients had their primary tumour resected in the standard way. Twenty-six of the patients served as controls, and 24 received fluorouracil, 1 g daily, as a continuous infusion into the portal venous system during the first seven days after operation. The patients were matched for age, sex, and site and stage of the disease. The immediate postoperative mortality and morbidity did not differ significantly between the two groups. During the follow-up period (mean duration 15.5 months), however, six deaths occurred in the control group and only one in the perfusion group. At necropsy four of the controls had multiple liver metastases. Two of the surviving controls developed evidence of liver metastases, and two had a local recurrence. No patient in the perfusion group developed evidence of hepatic metastases. These initial results suggest that adjuvant portal venous perfusion with fluorouracil may reduce the incidence of liver metastases in colorectal cancer.
Introduction. Simultaneous resection of primary colorectal carcinoma (CRC) and synchronous liver metastases (SLMs) is subject of debate with respect to morbidity in comparison to staged resection. The aim of this study was to evaluate our initial experience with this approach. Methods. Five patients with primary CRC and a clinical diagnosis of SLM underwent combined laparoscopic colorectal and liver surgery. Patient and tumor characteristics, operative variables, and postoperative outcomes were evaluated retrospectively. Results. The primary tumor was located in the colon in two patients and in the rectum in three patients. The SLM was solitary in four patients and multiple in the remaining patient. Surgical approach was total laparoscopic (2 patients) or hand-assisted laparoscopic (3 patients). The midline umbilical or transverse suprapubic incision created for the hand port and/or extraction of the specimen varied between 5 and 10 cm. Median operation time was 303 (range 151–384) minutes with a total blood loss of 700 (range 200–850) mL. Postoperative hospital stay was 5, 5, 9, 14, and 30 days. An R0 resection was achieved in all patients. Conclusions. From this initial single-center experience, simultaneous laparoscopic colorectal and liver resection appears to be feasible in selected patients with CRC and SLM, with satisfying short-term results.
Leakage from colonic anastomosis is a major complication causing increased mortality and morbidity. Ischemia is a well-known cause of this event. This study was designed to investigate the effects of adrenomedullin on the healing of ischemic colon anastomosis in a rat model.
Standardized left colon resection 3 cm above the peritoneal reflection and colonic anastomosis were performed in 40 Wistar rats that were divided into four groups. To mimic ischemia, the mesocolon was ligated 2 cm from either side of the anastomosis in all of the groups. The control groups (1 and 2) received no further treatment. The experimental groups (3 and 4) received adrenomedullin treatment. Adrenomedullin therapy was started in the perioperative period in group 3 and 4 rats (the therapeutic groups). Group 1 and group 3 rats were sacrificed on postoperative day 3. Group 2 and group 4 rats were sacrificed on postoperative day 7. After careful relaparotomy, bursting pressure, hydroxyproline, malondialdehyde, interleukin 6, nitric oxide, vascular endothelial growth factor, and tumor necrosis factor alpha levels were measured. Histopathological characteristics of the anastomosis were analyzed.
The group 3 animals had a significantly higher bursting pressure than group 1 (p<0.05). Hydroxyproline levels in group 1 were significantly lower than in group 3 (p<0.05). The mean bursting pressure was significantly different between group 2 and group 4 (p<0.05). Hydroxyproline levels in groups 3 and 4 were significantly increased by adrenomedullin therapy relative to the control groups (p<0.05). When all groups were compared, malondialdehyde and nitric oxide were significantly lower in the control groups (p<0.05). When vascular endothelial growth factor levels were compared, no statistically significant difference between groups was observed. Interleukin 6 and tumor necrosis factor alpha were significantly decreased by adrenomedullin therapy (p<0.05). The healing parameters and inflammatory changes (e.g., granulocytic cell infiltration, necrosis, and exudate) were significantly different among all groups (p<0.05).
Adrenomedullin had positive effects on histopathologic anastomotic healing in this experimental model of ischemic colon anastomosis.
Colonic anastomosis; Ischemia; Adrenomedullin; Oxidative damage; Neovascularization
Leiomyosarcoma of the inferior vena cava (IVCL) is a rare retroperitoneal tumor. We report two cases of level II (middle level, renal veins to hepatic veins) IVCL, who underwent en bloc resection with reconstruction of bilateral or left renal venous return using prosthetic grafts. In our cases, IVCL is documented to be occluded preoperatively, therefore, radical resection of tumor and/or right kidney was performed and the distal end of inferior vena cava was resected and without caval reconstruction. None of the patients developed edema or acute renal failure postoperatively. After surgical resection, adjuvant radiation therapy was administrated. The patients have been free of recurrence 2 years and 3 months, 9 months after surgery, respectively, indicating the complete surgical resection and radiotherapy contribute to the better survival. The reconstruction of inferior vena cava was not considered mandatory in level II IVCL, if the retroperitoneal venous collateral pathways have been established. In addition to the curative resection of IVCL, the renal vascular reconstruction minimized the risks of procedure-related acute renal failure, and was more physiologically preferable. This concept was reflected in the treatment of the two patients reported on.
Leiomyosarcoma; Inferior vena cava; Renal veins; Reconstruction
Despite numerous studies in the past it is not possible yet to predict postoperative liver failure
and safe limits for hepatectomy. In this study the following liver function tests ICG-ER
(indocyaninegreen elimination rate), GEC (galactose elimination capacity) and MEGX-F
(monoethylglycinexylidid formation) are examined with regard to loss of liver tissue and
prediction of operative risk. Liver function tests were assessed in 20 patients prior to liver
resection and on the 10th. postoperative day. Liver and tumor volume were measured by
ultrasound and pathologic specimen and the parenchymal resection rate was calculated. In
patients without cirrhosis (n = 10) ICG-ER and MEGX-F remained unchanged after
resection, GEC was reduced but did not correspond to the resection rate. Patients with
cirrhosis (n = 10) had a significantly lower ICG-ER and GEC before resection than patients
without cirrhosis. After resection these tests were unchanged. Patients with liver related
complications and cirrhosis (n = 5) had lower ICG-ER and GEC than patients with cirrhosis
and no complications. In the postoperative course all liver function tests in these patients were
significantly lower compared to preoperative results. Comparing liver function tests ICG
serves best to indicate postoperative liver failure. Liver function tests do not correspond with
loss of liver tissue.
Objectives: To investigate the intestinal microflora status related to ischemia/reperfusion (I/R) liver injury and explore the possible mechanism. Methods: Specific pathogen free grade Sprague-Dawley rats were randomized into three groups: Control group (n=8), sham group (n=6) and I/R group (n=10). Rats in the control group did not receive any treatment, rats in the I/R group were subjected to 20 min of liver ischemia, and rats in the sham group were only subjected to sham operation. Twenty-two hours later, the rats were sacrificed and liver enzymes and malondialdehyde (MDA), superoxide dismutase (SOD), serum endotoxin, intestinal bacterial counts, intestinal mucosal histology, bacterial translocation to mesenteric lymph nodes, liver, spleen, and kidney were studied. Results: Ischemia/reperfusion increased liver enzymes, MDA, decreased SOD, and was associated with plasma endotoxin elevation in the I/R group campared to those in the sham group. Intestinal Bifidobacteria and Lactobacilli decreased and intestinal Enterobacterium and Enterococcus, bacterial translocation to kidney increased in the I/R group compared to the sham group. Intestinal microvilli were lost, disrupted and the interspace between cells became wider in the I/R group. Conclusion: I/R liver injury may lead to disturbance of intestinal microflora and impairment of intestinal mucosal barrier function, which contributes to endotoxemia and bacterial translocation to kidney.
Ischemia/reperfusion (I/R); Liver injury; Microflora; Endotoxin; Bacterial translocation
The object of this study is to evaluate the radiological and pathological changes in the sinus of an experimental arteriovenous fistula of the rat.
Twenty-five male Sprague-Dawley rats, including two control rats, were used for this study. A venous hypertension model in the transverse sinus was induced by means of anastomosis of a common carotid artery (CCA) to the ipsilateral external jugular vein (EJV). Rats were sacrificed 11 to 42 weeks after the procedure, then histopathological and immunohistopathological examinations were performed for the resected transverse sinus. Follow-up angiography was performed two to three weeks after the anastomosis in every case, and five months later in two rats.
Patency of the anastomosed portion was confirmed in 12 of the 23 anastomosed rats. An ipsilateral carotid angiogram demonstrated a high-flow arteriovenous (AV) shunt from the CCA to the sigmoid-to-transverse sinus and draining into the contralateral juglar vein. A contralateral angiogram displayed a steal phenomenon via the communicating artery.
Histopathologically, the vein of the anastomosed portion and the transverse sinus were markedly dilated in with cases. There was a thickening the connecting tissue and a proliferation of fibroblast in four (50%) of the eight cases. Thrombus formation in the transverse sinus was found in one case. VEGF stained strongly in the endothelial hypertrophied area and in fibrous connective tissue around the transverse sinus compared to the control sinuses.
Our results from this long-term observation of the radiological and pathological changes in the sinus exposed to hypertension resembled the clinical findings of a dural AV fistula.
dural arteriovenous fistula, experimental model, pathology
Collagen synthesis is an essential feature of anastomotic healing in the intestine. Postoperative collagen synthesis, measured in vitro in intestinal anastomoses was studied from three hours to 28 days after operation. For this purpose, an ileal and a colonic anastomosis were constructed within the same animal and the results in both intestinal segments were compared. In the ileum, collagen synthesis was significantly increased, with respect to unoperated controls, three hours after operation. It remained raised during the period of study, with a maximal 10-fold stimulation four days after operation, and had nearly returned to the preoperative level after four weeks. The general pattern was the same in the colon, although quantitatively different: the increase in synthetic activity was delayed in comparison with the ileum. Maximal stimulation was approximately six-fold. In addition, we calculated the ratio for each rat between anastomotic collagen synthesis and the average value found in non-operated control animals. Postoperative stimulation in the ileum was higher than in the colon in almost every animal examined. The results show that the ileum responds more quickly and strongly to wounding than the colon, at least as far as the production of new collagen is concerned. Possibly, this phenomenon contributes to the lower failure rate apparent for anastomoses in the small bowel.
The optimal surgical strategy for resectable, synchronous, colorectal liver metastases remains unclear. The objective of this study was to determine which patients could benefit from staged resections instead of simultaneous resection by identifying predictive factors for postoperative morbidity and anastomotic leakage after simultaneous resection of synchronous, colorectal liver metastases and the primary colorectal tumor.
This study involved 86 patients with synchronous colorectal liver metastases who underwent simultaneous resection of the primary colorectal tumor and the hepatic tumor. Postoperative mortality, morbidity, and other surgical outcomes, including survival and hospitalization, were assessed. Predictive factors for postoperative morbidity and for anastomotic leakage were evaluated.
Postoperative morbidity and anastomotic leakage were found in 55 (64%) and 18 (21%) patients. Predictive factors for postoperative morbidity and for anastomotic leakage were intraoperative blood loss and operation time >8 h, respectively. The overall 5-year survival rate was 45%.
The frequency of morbidity and that of anastomotic leakage seemed to be high after simultaneous resection for synchronous colorectal liver metastases, especially when intraoperative blood loss or operation time increased greatly. Staged resections should be considered in cases in which excessive surgical stress from simultaneous resection of synchronous colorectal liver metastases would be expected.
Colorectal cancer; Hepatic metastasis; Liver metastasis; Morbidity; Anastomotic leakage