Michael Texler

Variables in the spread of tumor cells to trocars and port sites during operative laparoscopy

BACKGROUND: Port-site recurrences have delayed the uptake of laparoscopic colectomy, but the etiology of these is incompletely understood. These studies were designed to investigate variables such as the size of the tumor inoculum and the volume and pressure of the insufflated gas during operative laparoscopy that might affect the deposition of these cells in relation to trocars and port sites. METHODS: Radiolabeled human colon cancer cells were injected into the peritoneal cavity of pigs. Three trocars were inserted, and the abdomen was insufflated with carbon dioxide. The movement of cells within the abdomen was traced on a gamma camera. After 2 h, the trocars were removed and the port sites excised. Two studies were performed. In the first study, tumor inocula were varied from 1.5 × 105 to 120 × 105. In the second study, insufflation pressure was varied, with pressures 0, 4, 8 and 12 mmHg were studied. RESULTS: When larger tumor inocula were injected, the contamination of both trocars (p = 0.005, Kendalls rank correlation) and trocar sites (p = 0.04, Kendalls rank correlation) increased. The deposition of cells on a trocar site was linked to contamination of its trocar (p = 0.03, chi-square), but the contamination of trocars did not always result in trocar-site contamination (p = 0.5, chi-square). Increased volumes of gas insufflation caused increased intraabdominal movement of tumour cells (p = 0.01, Kendalls rank correlation), although this did not lead to greater contamination of trocars or port sites (p = 0.82, Kendalls rank correlation). Decreased insufflation pressures resulted in increased contamination of trocars and port sites (p = 0.01, Kendalls rank correlation). CONCLUSIONS: If clinical situations parallel this study, strategies such as increasing insufflation pressure, reducing episodes of desufflation and gas leaks, and using frequent intraabdominal lavage may help to reduce the numbers of viable tumor cells displaced to port sites during laparoscopic surgery for intraabdominal malignancy. This may reduce the rate of port-site metastases.

Liver electrolysis: pH can reliably monitor the extent of hepatic ablation in pigs

Electrolysis is a method of tissue ablation that creates chemical species and a pH gradient in response to direct current. Initial studies of electrolysis in animal models and humans have shown that it is a safe, predictable and effective process for destroying normal and tumour-bearing liver in a linear, dose-dependent manner. Presently, the amount of current that is applied (in coulombs) has to be calculated using historical data, with inherent inaccuracy. The present study tested whether pH could be used as a real-time monitor in order to predict more accurately the extent of necrosis. A total of 70 electrolytic lesions were created in 14 pigs, with pH monitoring of the lesion edge. The normal range of pH values was 6.5-8.7. A pH of less than 6 (at the anode) or more than 9 (at the cathode) reflected total cellular necrosis. When a pH value was recorded between 6.0 and 6.5 at the anode or between 8.7 and 9.0 at the cathode, the presence of necrosis was variable. In conclusion, during electrolytic ablation, pH measurement can monitor the extent of the induced necrosis.

CASE REPORT: A hepatocellular carcinoma metastasis in the distal pancreas

Hepatocellular carcinoma is a highly malignant neoplasm. Extrahepatic metastases are found in 64% of patients with hepatocellular carcinoma. The lungs, regional lymph nodes, kidney, bone marrow and adrenals are common sites of metastases. Pancreatic metastases are not common (<5%). A case report of a hepatocellular carcinoma with a metastasis in the distal pancreas is presented. A resection of the primary tumour and metastasis was carried out with the patient still alive 16 months after resection. This case illustrates that hepatic resection for hepatocellular carcinoma with a single local metastasis can be reasonably considered although a cure has not been established.

Endoscopic perductal electrolytic ablation of the pancreas: Experimental studies of morbidity and mortality

Background: Palliation of pancreatic cancer remains the only option for the majority of patients. Palliative techniques such as surgical bypass and endoscopic retrograde cholangiopancreatography (ERCP) with stenting are not ideal. The ‘ideal’ palliative technique would combine the efficacy of surgery with the minimal complications of an endoscopic procedure. Endoscopically delivered perductal electrolytic ablation of pancreatic lesions has the potential to meet these criteria. Methods: Fifteen pigs were used. The pancreatic duct was cannulated with an electrolysis catheter. Animals were randomised to either: controls, treatment 2-week survivor or treatment 8-week survivor. An electrolytic dose was administered to the treatment animals. Post-operatively, serum amylase and leucocyte count were assessed. Pancreata were histologically examined to detect evidence of acute pancreatitis. Results: Electrolysis was well tolerated. There was no difference in post-operative hyperamylasaemia and leucocyte count between the groups. Histological examination showed inflammation at the ablation site at 2 weeks, by 8 weeks this was replaced by scarring. Conclusion: The results of this study suggest that endoscopic perductal electrolytic ablation of the pancreas is feasible and safe. Biochemical and histological findings indicate self-limiting localised inflammation of the pancreas. This technique may have a role in the palliation of pancreatic cancer and warrants further investigation.

Perductal electrolytic ablation of the porcine pancreas: A minimally invasive option-studies of morbidity and mortality

BackgroundPancreatic cancer has a dismal prognosis. Few patients are suitable for surgical resection, leaving the majority requiring symptom palliation. Current palliative techniques such as surgical bypass and endoscopic retrograde cholangiopancreatography (ERCP) are imperfect. A novel palliative therapy combining the symptom control of surgical bypass with the minimally invasive nature of ERCP is required.MethodsPerductal electrolytic ablation of pancreatic tissue, in a porcine model, was performed. There were two survival groups of 2 weeks (n = 4) and 8 weeks (n = 4). Postoperatively, serum biochemistry, amylase and C-reactive protein (CRP) were assessed. Histological examination of the pancreas, lungs, and kidneys was performed to determine the presence of acute pancreatitis or systemic inflammatory response.ResultsAn immediate transient increase in both amylase and CRP was seen. Although pancreatic histology demonstrated localised necrosis at the electrolytic site at 2 weeks, there was no evidence of generalized pancreatitis or a systemic inflammatory response at either 2 or 8 weeks.ConclusionsThis study suggests that, although there is localized pancreatic necrosis and transient hyperamylasemia, perductal pancreatic electrolytic ablation is safe, with neither generalized pancreatitis nor a systemic inflammatory response, in the medium and long term. Although performed in normal porcine pancreas, because of the absence of a large-animal model of pancreatic cancer, this study suggests that electrolytic pancreatic ablation is safe. This technique may have a role in the palliation of pancreatic cancer, especially if delivered via a minimally, invasive approach, and warrants further investigation.

Left extended hemihepatectomy with preservation of large inferior right hepatic vein: a case report.

For hepatic function to be preserved after an extended hemihepatectomy adequate venous drainage of the remaining liver is required. Most metastases close to the confluence of the superior hepatic veins are considered unresectable because hepatic venous outflow after resection would be compromised. In 10–25% of people, the inferior right hepatic vein is of large calibre. Thus the superior hepatic veins may be sacrificed and hepatic function preserved if a large inferior right hepatic vein is present. A patient with involvement of segments 2, 4 and 8 by metastatic colorectal cancer is presented. This patient had a large inferior right hepatic vein, and so was able to undergo an extended left hemihepatectomy with ligation of all superior hepatic veins. Subsequent quality of life was maintained. This case illustrates that an ‘unresectable’ hepatic lesion can be actually resectable if an alternative venous drainage is present. A pre-operative search for a prominent inferior right hepatic vein by ultrasound, computerised tomography, or even magnetic resonance imaging should be considered in these cases.

Successful treatment of renal allograft and bladder malakoplakia with minimization of immunosuppression and prolonged antibiotic therapy.

Malakoplakia is an unusual granulomatous inflammatory disorder associated with diminished bactericidal action of leucocytes that occurs in immunosuppressed hosts. Cases of renal allograft malakoplakia are generally associated with a poor graft and patient survival. We present the case of a 56‐year‐old female with allograft and bladder malakoplakia occurring two years after renal transplantation complicated by an early antibody mediated rejection. Following a number of symptomatic urinary tract infections caused by resistant Gram‐negative bacilli, a diagnosis of malakoplakia was made by biopsy of a new mass lesion of the renal allograft. Cystoscopy also revealed malakoplakia of the bladder wall. Immunosuppressant regimen was modified. Mycophenolate mofetil was ceased, prednisolone reduced to 5 mg/day and tacrolimus concentrations were carefully monitored to maintain trough serum concentrations of 2–4 μg/L. Concurrently, she received a prolonged course of intravenous antibiotics followed by 13 months of dual oral antibiotic therapy with fosfomycin and faropenem. This joint approach resulted in almost complete resolution of allograft malakoplakia lesions and sustained regression of bladder lesions on cystoscopy with histological resolution in bladder lesions. Her renal function has remained stable throughout the illness. If treated with sustained antimicrobial therapy and reduction of immunosuppression, cases of allograft malakoplakia may not necessarily be associated with poor graft survival.

Electrolysis - a new method of renal ablation?

Whats known on the subject? and What does the study add?