Safety and feasibility of chemotherapy followed by liver transplantation for patients with definitely unresectable colorectal liver metastases: insights from the TransMet randomised clinical trial.

Background: Despite the increasing efficacy of chemotherapy (C), the 5-year survival rate for patients with unresectable colorectal liver metastases (CLM) remains around 10%. Liver transplantation (LT) might offer a curative approach for patients with liver-only disease, yet its superior efficacy compared to C alone remains to be demonstrated. Methods: The TransMet randomised multicentre clinical trial (NCT02597348) compares the curative potential of C followed by LT versus C alone in patients with unresectable CLM despite stable or responding disease on C. Patient eligibility criteria proposed by local tumour boards had to be validated by an independent committee via monthly videoconferences. Outcomes reported here are from a non-specified interim analysis. These include the eligibility of patients to be transplanted for non resectable colorectal liver metastases, as well as the feasibility and the safety of liver transplantation in this indication. Findings: From February 2016 to July 2021, 94 (60%) of 157 patients from 20 centres in 3 countries submitted to the validation committee, were randomised. Reasons for ineligibility were mainly tumour progression in 50 (32%) or potential resectability in 13 (8%). The median delay to LT after randomisation was 51 (IQR 30-65) days. Nine of 47 patients (19%, 95% CI: 9-33) allocated to the LT arm failed to undergo transplantation because of intercurrent disease progression. Three of the 38 transplanted patients (8%) were re-transplanted, one of whom (3%) died post-operatively from multi-organ failure. Interpretation: The selection process of potential candidates for curative intent LT for unresectable CLM in the TransMet trial highlighted the critical role of an independent multidisciplinary validation committee. After stringent selection, the feasibility of LT was 81%, as 19% had disease progression while on the waiting list. These patients should be given high priority for organ allocation to avoid dropout from the transplant strategy. Funding: No source of support or funding from any author to disclose for this work. The trial was supported by the Assistance Publique - Hôpitaux de Paris (AP-HP).

International Hepato-Pancreato-Billiary Association (IHPBA) registry study on COVID-19 infections in HPB surgery patients.

BACKGROUND: In response to the pandemic, the International Hepato-Pancreato-Biliary Association (IHPBA) developed the IHPBA-COVID Registry to capture data on HPB surgery outcomes in COVID-positive patients prior to mass vaccination programs. The aim was to provide a tool to help members gain a better understanding of the impact of COVID-19 on patient outcomes following HPB surgery worldwide. METHODS: An online registry updated in real time was disseminated to all IHPBA, E-AHPBA, A-HPBA and A-PHPBA members to assess the effects of the pandemic on the outcomes of HPB procedures, perioperative COVID-19 management and other aspects of surgical care. RESULTS: One hundred twenty-five patients from 35 centres in 18 countries were included. Seventy-three (58%) patients were diagnosed with COVID-19 preoperatively. Operative mortality after pancreaticoduodenectomy and major hepatectomy was 28% and 15%, respectively, and 2.5% after cholecystectomy. Postoperative complication rates of pancreatic procedures, hepatic interventions and biliary interventions were respectively 80%, 50% and 37%. Respiratory complication rates were 37%, 31% and 10%, respectively. CONCLUSION: This study reveals a high risk of mortality and complication after HPB surgeries in patient infected with COVID-19. The more extensive the procedure, the higher the risk. Nonetheless, an increased risk was observed across all types of interventions, suggesting that elective HPB surgery should be avoided in COVID positive patients, delaying it at distance from the viral infection.

Changing liver utilization and discard rates in clinical transplantation in the ex-vivo machine preservation era.

Liver transplantation is a well-established treatment for many with end-stage liver disease. Unfortunately, the increasing organ demand has surpassed the donor supply, and approximately 30% of patients die while waiting for a suitable liver. Clinicians are often forced to consider livers of inferior quality to increase organ donation rates, but ultimately, many of those organs end up being discarded. Extensive testing in experimental animals and humans has shown that ex-vivo machine preservation allows for a more objective characterization of the graft outside the body, with particular benefit for suboptimal organs. This review focuses on the history of the implementation of ex-vivo liver machine preservation and how its enactment may modify our current concept of organ acceptability. We provide a brief overview of the major drivers of organ discard (age, ischemia time, steatosis, etc.) and how this technology may ultimately revert such a trend. We also discuss future directions for this technology, including the identification of new markers of injury and repair and the opportunity for other ex-vivo regenerative therapies. Finally, we discuss the value of this technology, considering current and future donor characteristics in the North American population that may result in a significant organ discard.

Graft survival after kidney transplantation with standard versus prolonged kidney procurement time.

BACKGROUND: During kidney procurement, after ice removal, kidneys located in the retroperitoneum are at risk for rewarming owing to the time taken to retrieve other abdominal and thoracic organs, which may lead to poorer outcomes. The purpose of this study was to evaluate the impact of prolonged kidney procurement time (PKP) on outcomes of kidney transplantation performed at the Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia, Canada. METHODS: We retrospectively reviewed the cases of all adult (age ≥ 18 yr) patients who underwent kidney transplantation at the Queen Elizabeth II Health Sciences Centre between Jan. 1, 2010, and Dec. 31, 2015. We included all patients who received kidney transplants from deceased donors with a minimum follow-up period of 3 years. We defined PKP as more than 65 minutes from aortic cross-clamp to final organ extraction, and standard procurement time (SP) as 65 minutes or less. RESULTS: Among the 455 transplantation procedures performed during the study period, we reviewed the cases of 145 patients who received kidneys from Nova Scotian donors and were followed in Nova Scotia. No statistically significant differences were seen in outcomes between kidney-only (n = 46) and multiorgan (n = 99) procurement, although more organs from kidney-only donors than multiorgan donors had a Kidney Donor Profile Index score greater than 50% (32 [69.6%] v. 48 [48.5%], p < 0.01). Compared to the SP group (n = 115), the PKP group (n = 30) had a higher rate of 30-day graft loss (6.7% v. 0.0%, p < 0.01), a higher incidence of de novo formation of donor-specific antibodies (3 [10.0%] v. 1 [0.9%], p < 0.01) and a lower 5-year graft survival rate (90.0% v. 97.4%, p = 0.03). Left kidneys remained 11 minutes longer on the donor than right kidneys when multiorgan procurement was performed (p < 0.01), and their 5-year survival rate was significantly lower than that of right kidneys (p = 0.03). CONCLUSION: Procurement times longer than 65 minutes may be associated with poorer outcomes after kidney transplantation. Measures to reduce kidney exposure to rewarming during procurement may improve long-term outcomes.

Comparison of open and closed abdomen techniques for the delivery of intraperitoneal pemetrexed using a murine model.

BACKGROUND AND OBJECTIVES: Pemetrexed is an appealing agent to use for cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). However, the optimal method of pemetrexed delivery still remains undefined. Using a murine model, we compared the use of open and closed abdomen techniques on the absorption of intraperitoneal (IP) pemetrexed in different compartments. METHODS: Eleven Sprague-Dawley rats were submitted to a fixed dose of IP pemetrexed (1000 mg/m2 ) at a perfusion temperature of 40°C during 25 min according to two techniques: open and closed. At the end of perfusion, samples in different compartments were harvested and the concentrations of pemetrexed were measured by high performance liquid chromatography. RESULTS: Absorption of IP pemetrexed in portal and systemic blood was significantly higher using the open compared to the closed abdomen technique (93.17 vs 52.50 µg/mL, P < 0.001) and (76.26 vs 51.65 µg/mL, P < 0.001), respectively. No difference was found between the two techniques on the peritoneal tissue concentration of pemetrexed (18.07 vs 19.17 µg/g, P = 0.51). CONCLUSION: Peritoneal absorption of pemetrexed is not modified by the use of either technique. However, systemic concentrations of pemetrexed increased using the open technique, suggesting it could increase systemic toxicity.

Obesity Paradox in Off-Pump Coronary Artery Bypass Surgery: Does It Benefit the Elderly?

BACKGROUND: The obesity paradox is a well-known phenomenon in cardiovascular disease; how it interferes with coronary artery revascularization remains controversial. The purpose of this study was to investigate the impact of obesity body mass index (BMI > 30; in kg/m2) on short- and long-term survival and major adverse cardiovascular event (MACE)-free survival in obese patients after off-pump coronary artery bypass operation. METHODS: We retrospectively reviewed our prospective cohort of 1,400 consecutive and systematic patients who underwent off-pump coronary artery bypass operation between September 1996 and November 2007 and identified 448 (32%) with preoperative BMI greater than 30. RESULTS: Patients with BMI greater than 30 patients were younger and had a higher prevalence of diabetes, dyslipidemia, hypertension, and percutaneous coronary interventions than patients with BMI less than 30. Thirty-day mortality and perioperative myocardial infarction were similar in both groups. No significant difference was observed for wound infections, sternal dehiscence, and reoperation for bleeding. Overall, long-term survival was comparable in the two groups, although obese patients older than 65 years had a better survival than the nonobese patients even after correction for risk factors (p = 0.04). MACE-free survival at 10 years was 65.3% ± 5.7% in obese and 76.3% ± 2.3% in nonobese patients (p = 0.007). Statistical significance was maintained (p = 0.008) after correction for risk factors. Among MACE, only new episodes of congestive heart failure were more prevalent in obese patients (p = 0.002). CONCLUSIONS: In our series of off-pump coronary artery bypass operation, obesity was not an independent cause of short- and long-term mortality and was shown beneficial for older patients. However, obese patients had a lower MACE-free survival because of an increased incidence of rehospitalization for congestive heart failure.

Pharmacokinetics and the effect of heat on intraperitoneal pemetrexed using a murine model.

BACKGROUND: Pemetrexed is a systemic chemotherapeutic agent used in the treatment of malignant mesothelioma. This drug represents a potentially promising intraperitoneal (IP) agent to use for hyperthermic intraperitoneal chemotherapy (HIPEC) in the treatment of peritoneal mesothelioma. However, this has yet to be supported by preclinical studies. Therefore, we aimed to study the effect of pemetrexed dose and perfusion temperature on the resultant pemetrexed concentration in 3 different compartments (systemic circulation, portal circulation and peritoneal tissues) using a murine model. METHODS: Under general anesthesia, 29 Sprague-Dawley rats were submitted to 3 different doses of IP pemetrexed (500, 1000 and 1500 mg/m2) combined with 3 different perfusion temperatures (37, 40 and 43 °C) for a total duration of 25 min. At the end of perfusion, samples in different compartments (systemic circulation, portal circulation and peritoneum) were harvested and concentrations of pemetrexed were measured using high performance liquid chromatography. RESULTS: With increasing dose of IP pemetrexed, higher concentrations were measured in the 3 compartments tested. In peritoneal cells, the difference between IP doses of 500 and 1000 mg/m2 (2.03 vs. 19.17 µg/g, p < 0.001) was greater than the difference between 1000 and 1500 mg/m2 (19.17 vs. 22.80 µg/g, p = 0.027). When the perfusion temperature increased, we observed a proportional rise of pemetrexed concentration in both the portal and systemic compartments; while in the peritoneal cells, the pemetrexed concentration increased up to 40 °C, after which it plateaued. CONCLUSION: Both heat and increasing doses of IP pemetrexed enhance peritoneal cell concentration of pemetrexed. However, for temperatures above 40 °C, pemetrexed concentration reached a plateau in peritoneal cells. Systemic and portal concentrations increased proportionally with both increasing temperatures and IP doses. We believe these results should be taken into consideration for the design of an eventual clinical study in humans.

Electrocautery effect on intestinal vascularisation in a murine model.

BACKGROUND: The use of electrocautery devices is associated with complications such as perforation or fistulisation when used near intestinal structures. This is likely due to its effect on vascularisation of the bowel wall. To test this hypothesis we established a murine model to quantify the effect of electrocautery injury on the intestinal microvascularisation. METHODS: Sprague-Dawley rats were subjected to five electrocautery injuries on the small bowel in coagulation mode (30 W intensity) and in cut mode (40 W, 80 W and 200 W intensities) for durations of 1, 2 and 5 s. 5 mg/kg of fluorescein was injected intravenously, the injured bowel segments harvested and the rat sacrificed. The segments were analysed to measure the fluorescence of injured bowel compared to adjacent unharmed tissue. RESULTS: A significant decrease in bowel wall microvascularisation occurred with increasing intensity (coag 30 W/cut 40 W versus cut 200 W 1 s: p < 0.05) and duration of electrocautery injury (cut 40 W 1/2 s versus 5 s: p < 0.05). There was a 40% perforation rate when decreased bowel wall microvascularisation was 25% or more. Despite similar electrocautery injury, a significantly greater microvascularisation decrease was observed in jejunum compared to ileum (p < 0.05). CONCLUSION: We successfully established a murine model to quantify the decrease of bowel wall microvascularisation associated with electrocautery use. Unsurprisingly, the decrease in microvascularisation is greater with higher intensity and duration of electrocautery and is associated with more perforations in the experimental model. The jejunum seems more vulnerable to electrocautery injury than the ileum. These observations support caution when using electrocautery devices near intestinal structures.

The perimount valve in the aortic position: twenty-year experience with patients under 60 years old.

BACKGROUND: With improved durability of contemporary bioprostheses, surgeons are now recommending biologic valves in younger patients. However, long-term outcomes of patients younger than 60 years old undergoing biologic aortic valve implantation are not well known. METHODS: From November 1991 to March 2011, 144 patients less than 60 years old underwent aortic valve replacement (AVR) with Carpentier-Edwards pericardial valves (Edwards Lifesciences, Irvine, CA). Mean follow-up was 10±4 years. Outcomes were reported according to published guidelines. RESULTS: Seventy-five percent of patients were male, with a mean age of 51±9 years. Actuarial survival rates including early deaths were 89%±3%, 79%±4%, and 57%±6% after 5, 10, and 15 years of follow-up, respectively. Survival of patients was comparatively lower than a gender- and age-matched general population at all time points. The freedom from major adverse cardiac events (myocardial infarction, heart failure, hemorrhage, thromboembolic event, and endocarditis) was 89%±3%, 87%±3%, and 75%±6% at 5, 10, and 15 years after surgery. The freedom rate from prosthetic valve dysfunction was 97%±2%, 84%±4%, and 57%±6% at 5, 10, and 15 years after surgery. Patients with a diagnosis of structural valve deterioration (29 of 37, 78%) underwent reoperation 11±5 years after the initial valve replacement with no perioperative mortality. CONCLUSIONS: In patients younger than 60 years undergoing AVR, the Carpentier-Edwards Perimount bioprosthesis provided satisfactory clinical outcomes. However, late survival was inferior to an age- and gender-matched population. Structural valve deterioration and the need for reintervention were common late after implantation, but reoperation for prosthetic valve dysfunction was associated with a very low risk of mortality.