Nayef A. Alzahrani

Heat sink effect on tumor ablation characteristics as observed in monopolar radiofrequency, bipolar radiofrequency, and microwave, using ex vivo calf liver model.

AbstractThermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices.With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored.With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres.Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected.Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5.MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink.

Systematic review of efficacy and outcomes of salvage liver transplantation after primary hepatic resection for hepatocellular carcinoma.

Upfront liver transplantation is the gold standard in the treatment of patients with hepatocellular carcinoma (HCC) and cirrhosis, but a shortage of donor organs negatively impacts on survival outcomes, with significant disease progression during long waiting lists. This systematic review evaluates the safety and efficacy of salvage liver transplantation (SLT) as treatment for recurrent HCC after initial hepatic resection.

Laparoscopic hyperthermic intraperitoneal chemotherapy (HIPEC) for refractory malignant ascites in patients unsuitable for cytoreductive surgery.

INTRODUCTION Malignant ascites (MA) is the abnormal accumulation of fluid in the peritoneal cavity of patients with intraperitoneal dissemination of their disease and is associated with a short life expectancy. The most common clinical feature is a progressive increase of abdominal distention resulting in pain, discomfort, anorexia and dyspnoea. Currently, no treatment is established standard of care due to limited efficacy or considerable toxicity. The objective was to examine the efficacy of laparoscopic hyperthermic intraperitoneal chemotherapy (HIPEC) in the palliation of refractory MA in patients who were unsuitable for cytoreductive surgery. METHODS From May 2009 to June 2015, 12 patients with MA due to their peritoneal malignancy were treated with laparoscopic HIPEC. The time between operation and repeat paracentesis, in-hospital data, and the proportion of patients that did not require repeat paracentesis was analyzed. RESULTS One patient (8%) was admitted to ICU for 1 day. The mean operating time and hospital stay was 149.3 min (range 79-185) and 4.6 days (range 2-11) respectively. Neither high-grade morbidity nor mortality was observed. The median OS was 57 days. In our experience, a complete and definitive disappearance of MA was observed in 83% of patients. Two patients (17%) developed recurrent MA 124 days and 283 days post-HIPEC. CONCLUSION Laparoscopic HIPEC is a beneficial treatment for the management and palliation of refractory MA and results in an excellent clinical and radiological resolution in patients with a complete resolution observed in selected patients.

Synchronous liver resection with cytoreductive surgery for the treatment of liver and peritoneal metastases from colon cancer: results from an Australian centre

Treatment of peritoneal metastases (PM) and liver metastases (LM) from colon cancer remains controversial. LM has been viewed as exclusion criterion for cytoreductive surgery (CRS) on the basis that such spread represents systemic disease. CRS and intraperitoneal chemotherapy (IPC) has gained increasing recognition as a treatment modality for selected patients with colon cancer and PM. This study analyses results of CRS and IPC for colon cancer and synchronous resection for treatment of LM and PM.

Long term results of RFA to lung metastases from colorectal cancer in 157 patients

INTRODUCTION We evaluated the long-term outcomes of 157 patients receiving radiofrequency ablation (RFA) to colorectal cancer (CRC) lung metastases. METHODS A total of 434 lesions were ablated in 199 procedures over 14 years. Thirty-two out of the 157 patients underwent multiple procedures. Our primary end-points were overall survival, disease free survival, procedure-related mortality and morbidity and various prognostic entities for survival. The survival in three subgroups were analysed: those that had undergone CRC resection and peritonectomy, CRC resection and liver resection and resection of their primary CRC alone. RESULTS 105 patients (67%) underwent pre-RFA liver resections, 14 patients (9%) underwent pre-RFA peritonectomies and 58 patients underwent only resection of their primary tumour. There were no procedurally related deaths. The mean duration of follow up was 28 months. A chest drain was required in 18.6% of all procedures. The overall median survival was 33.3 months. Survival at 1, 3 and 5 years was 89, 44 and 19.9% respectively. RFA post liver resection, post peritonectomy and post primary CRC resection alone saw median survivals of 38 months, 26 months and 27 months respectively. Tumour free survival at 12 months, 3 years and 5 years was 60.5%, 14.4% and 7% respectively. Lesion size, lesion number and pre-RFA CEA levels were not prognostic factors for overall survival or disease free survival. CONCLUSION RFA is now an accepted alternative treatment modality for CRC lung metastases in selected groups of patients. RFA has a reasonable morbidity profile and a demonstrated benefit for survival in these patients.

Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Methodology, Drugs and Bidirectional Chemotherapy

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) combined have been recognized as standard of care for treatment of a subset of patients with peritoneal carcinomatosis (PC). The aim of CRS is to eliminate all macroscopic disease through a series of visceral resections followed by targeting any residual microscopic disease with intraperitoneal chemotherapy, exposing the peritoneal surfaces to a high concentration of chemotherapy with a lower systemic toxicity. Different regimes of intraperitoneal chemotherapy include HIPEC, early postoperative intraperitoneal chemotherapy (EPIC) and bidirectional chemotherapy. The efficacy and modality of treatment with intraperitoneal chemotherapy is dependent on multiple factors including the chosen cytotoxic agent and its pharmacokinetics and pharmacodynamics. There is no standardized methodology for intraperitoneal chemotherapy administration. This review will discuss the pharmacological principles of the various intraperitoneal chemotherapy techniques.

Repeat cytoreductive surgery (CRS) for recurrent colorectal peritoneal metastases: Yes or no?

PURPOSE To clarify the role of repeat CRS for recurrent colorectal carcinoma (CRC) through: (i) Systematic review of the literature (ii) Analysis of survival outcomes in a prospective cohort. METHODS (i) Pubmed and MEDLINE from 1980 to July 2013 searched using terms: colorectal carcinoma, peritonectomy, cytoreductive surgery, hyperthermic intraperitoneal chemotherapy (HIPEC), redo, repeat, and iterative. (ii) Kaplan-Meier Survival analysis of consecutive patients undergoing repeat CRS at St George Hospital between Jan 2000 and July 2013. RESULTS (i) The search strategy yielded 309 articles, 5 meeting inclusion criteria, reporting on 91 patients. Median overall survival from first CRS ranged from 39 to 57.6 months with 3-yr survival of 50%, and 5-year survival of 30%. Median survival from second CRS was 20-months with 1-yr survivals of 72% and 66% and 2-year survivals of 50% and 44%. (ii) Repeat CRS performed on 18 patients found median survival from first CRS was 59 months, with 1, 3, and 5-year survival of 100%, 52% and 26% respectively. Median survival from repeat CRS was 22.6 months with 1, 2, and 3-year survival of 94%, 48% and 12% respectively. CONCLUSION The current data on repeat CRS in CRC is relatively immature and more data is required before drawing clear conclusions. Patient selection should be on a case by case basis conducted through a MDT process with emphasis on surrogate markers for favourable outcomes.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: long-term results at St George Hospital, Australia.

Peritoneal carcinomatosis (PC) results from the secondary spread of many intraabdominal tumour types, such as colorectal malignancy (colorectal cancer, CRC), disseminated peritoneal adenomucinosis (DPAM), appendiceal cancer, ovarian carcinoma, sarcoma or from the occurrence of primary peritoneal disease such as peritoneal mesothelioma. The combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has seen improvements in survival in selected cases of these cancers.

Impacts of low peritoneal cancer index on the survival outcomes of patient with peritoneal carcinomatosis of colorectal origin

INTRODUCTION The combination of cytoreductive surgery (CRS) and perioperative chemotherapy (PIC) have been proposed as an innovative technique for peritoneal carcinomatosis and is currently considered as a standard treatment for colorectal peritoneal carcinomatosis (CRPC) in selected patients. Peritoneal cancer index (PCI) has been suggested to be the most important prognostic factors for the outcomes of patients with CRPC. In this paper, we have studied patients with CRPC and a very low PCI of 5 or less and their survival outcomes. METHODS This is a retrospective study of prospectively collected data of 60 consecutive patients with CRPC and PCI ≤ 5, who underwent CRS and PIC by the same surgical team at St George hospital in Sydney, Australia between January 1996 and April 2015. Clinical outcomes of these patients were analysed. RESULTS Hospital mortality was 0%. 14 patients (23.4%) had grade III/IV morbidity. The median follow-up was 22.2 months (range = 0.1-104.2). The median survival was 80.6 months (95% confidence interval (CI) = 35.1-126.1), with an overall 1-year, 3-year, and 5-year survival rate of 96.1%, 72.6% and 54.7% respectively. Among 60 patients, 31 patients experienced the recurrence of the disease (51.7%). The median disease-free survival was 10.8 months (95% CI = 7.2-14.4). CONCLUSION This innovative approach combining CRS and PIC has shown encouraging outcomes and offers hope for patients with CRPC. Our results suggest that CRS and PIC can be performed safely to provide significant survival benefits for patients with low volume of disease. Early referral to specialist centre for evaluation is warranted for better survival outcomes.

Repeat cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for recurrent diffuse malignant peritoneal mesothelioma

INTRODUCTION Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has shown to improve survival outcomes for patients with diffuse malignant peritoneal mesothelioma (DMPM). PATIENTS AND METHODS This is a retrospective study of prospectively collected data of 44 consecutive patients with DMPM who underwent CRS and HIPEC by the same surgical team at St George Hospital in Sydney, Australia. A total of 58 operations were performed. Clinical data were divided according to the number of operation and HIPEC the patient had undergone (Group 1 = initial CRS and HIPEC; Group 2 = 2nd CRS and HIPEC; Group 3 included 3rd CRS and HIPEC; Group 4 = 4th CRS and HIPEC). A significant difference was defined as p < 0.05. RESULTS There were no significant differences in mortality and morbidity results among the four groups. The median survival for those who only had one operation was 22 months (95% confidence interval (CI) = 0-47.2), whereas the median survival for those who had a second operation was 62 months (95% CI = 22.9-101.1). However, such a difference did not translate into a statistical significance (p = 0.141). CONCLUSION We report an encouraging median survival of 62 months in patients who had recurrence of disease and had repeat CRS and HIPEC with similar morbidity and mortality with the initial operation. Due to the learning curve of this technique, patients with recurrent mesothelioma should be referred to specialised tertiary care centres for evaluation. Selected patients may experience prolonged survival after repeat CRS and HIPEC.