[Show abstract][Hide abstract] ABSTRACT: Introduction. Normothermic machine perfusion (NMP) is an emerging preservation modality that holds the potential to prevent the injury associated with low temperature and to promote organ repair that follows ischemic cell damage. While several animal studies have showed its superiority over cold storage (CS), minimal studies in the literature have focused on safety, feasibility, and reliability of this technology, which represent key factors in its implementation into clinical practice. The aim of the present study is to report safety and performance data on NMP of DCD porcine livers. Materials and Methods. After 60 minutes of warm ischemia time, 20 pig livers were preserved using either NMP (n = 15; physiologic perfusion temperature) or CS group (n = 5) for a preservation time of 10 hours. Livers were then tested on a transplant simulation model for 24 hours. Machine safety was assessed by measuring system failure events, the ability to monitor perfusion parameters, sterility, and vessel integrity. The ability of the machine to preserve injured organs was assessed by liver function tests, hemodynamic parameters, and histology. Results. No system failures were recorded. Target hemodynamic parameters were easily achieved and vascular complications were not encountered. Liver function parameters as well as histology showed significant differences between the 2 groups, with NMP livers showing preserved liver function and histological architecture, while CS livers presenting postreperfusion parameters consistent with unrecoverable cell injury. Conclusion. Our study shows that NMP is safe, reliable, and provides superior graft preservation compared to CS in our DCD porcine model.
[Show abstract][Hide abstract] ABSTRACT: Introduction: Normothermic machine perfusion (NMP) of the liver is a promising preservation modality that holds the potential to better preserve and even repair marginal grafts. In spite of several literature studies showing the benefits of NMP over cold storage, there is paucity of data regarding the mechanisms involved in the optimization of the microcirculation during preservation of these organs. We present our data on the impact of different vasodilators on DCD porcine livers preserved with NMP.Materials and methods: Livers from 15 female Yorkshire pigs (30-40 kg) were subjected to 60 min of WIT followed by 10 h of NMP. Group PC (n = 5) received a prostacyclin analog (epoprostenol sodium) and the AD group (n = 5) received adenosine, whereas group WV (n = 5) was perfused without using any vasodilator. Liver function was assessed by measuring, liver enzyme levels, bile production rate, and histological analysis.Results: At the end of perfusion, the PC group showed significantly lower AST (583 ± 62 vs. 2471 ± 745 and 2547 ± 690 IU/dl), ALT (41 ± 3 vs. 143 ± 28 and 111 ± 25 IU/dl) and LDH (840 ± 85 vs. 2756 ± 408 and 4153 ± 1569 IU/dl) levels compared to the AD and WV groups respectively (p<0.05). Bile production was significantly higher in the PC group compared to the AD group and WV, respectively (95 ± 9 vs. 37 ± 10 and 45 ± 18ml) (p<0.05). Histological samples of the PC group showed preserved hepatic architecture while those of the AD group and WV showed sinusoidal dilatation, architectural distortion, and profuse intraparenchymal hemorrhage.Conclusions: Maintenance of optimal microcirculatory homeostasis using proper vasodilators is a key factor in NMP of DCD livers.
The International journal of artificial organs 02/2014; · 1.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Encapsulating peritoneal sclerosis (EPS) is a rare but devastating complication of peritoneal dialysis characterized by fibrosis and calcification of the intestine that, in severe cases, can progress to intestinal failure and total parenteral nutrition dependency. Medical and surgical interventions carry a poor prognosis in these patients. We describe a case of a 36-year-old female with end-stage kidney disease and severe EPS not amenable to surgical intervention who underwent a combined intestinal and kidney transplantation. At 3 years posttransplantation, the patient has normal intestinal and kidney function. This represents, to our knowledge, the first report of severe EPS and end-stage kidney disease treated with a combined transplant.
American Journal of Transplantation 12/2013; 13(12):3274-3277. · 6.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abdominal closure is a complex surgical problem in intestinal transplant recipients with loss of abdominal domain, as graft exposure results in profound morbidity. Although intraoperative coverage techniques have been described, this is the first report of preoperative abdominal wall augmentation using tissue expanders in patients awaiting intestinal transplantation. We report on five patients who received a total of twelve tissue expanders as a means to increase abdominal surface area. Each patient had a compromised abdominal wall (multiple prior operations, enterocutaneous fistulae, subcutaneous abscesses, stomas) with loss of domain and was identified as high risk for an open abdomen post-transplant. Cross-sectional imaging and dimensional analysis were performed to quantify the effect of the expanders on total abdominal and intraperitoneal cavity volumes. The overall mean increase in total abdominal volume was 958 cm(3) with a mean expander volume of 896.5 cc. Two expanders were removed in the first patient due to infection, but after protocol modification, there were no further infections. Three patients eventually underwent small bowel transplantation with complete graft coverage. In our preliminary experience, abdominal tissue expander placement is a safe, feasible, and well-tolerated method to increase subcutaneous domain and facilitate graft coverage in patients undergoing intestinal transplantation.
Transplant International 08/2013; · 3.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Living donor liver transplantation (LDLT) is a well-established strategy to decrease the mortality in the waiting list and recent studies have demonstrated its value even in patients with low MELD score. However, LDLT is still under a high level of scrutiny because of its technical complexity and ethical challenges as demonstrated by a decline in the number of procedures performed in the last decade in Western Countries. Many aspects make LDLT different from deceased donor liver transplantation, including timing of transplantation, procedure-related complications as well as immunological factors that may affect graft outcomes. Our review suggests that in selected cases, LDLT offers significant advantages over deceased donor liver transplantation and should be used more liberally.
Transplant International 09/2012; · 3.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Intra-abdominal desmoid tumors are one of the leading causes of death in patients with familial adenomatous polyposis. Their behavior is unpredictable and their biology is poorly understood, accounting for the lack of a standardized medical and surgical approach. The aim of this study was to evaluate the mortality rate of patients with intra-abdominal desmoid tumors and to identify prognostic factors for the evolution of the disease.
A total of 154 patients with intra-abdominal desmoid tumors were included in the study. Each tumor was staged and each patient was categorized according to the stage of their most advanced tumor. Mortality was analyzed and the univariate risk factors associated with survival were included in a multivariable Cox regression model. A scoring system was derived from the multivariate analysis to refine outcomes within stages.
Five-year survival of patients with stage I, II, III, and IV intra-abdominal desmoid tumor were 95%, 100%, 89%, and 76% respectively (P < 0.001). Severe pain/narcotic dependency, tumor size larger than 10 cm, and need for total parenteral nutrition were shown to further define survival within stages. Five-year survival rate of stage IV patient with all of the above-mentioned risk factors was only 53%.
Our study confirmed the validity of the staging system to predict mortality in patients with intra-abdominal desmoid tumors and identified additional risk factors able to better define the risk of death within each stage. Risk stratification is crucial in directing patients with advanced disease and poor prognosis to the most appropriate medical and surgical options.
Annals of surgery 03/2012; 255(3):511-6. · 7.90 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Most solid-organ transplants performed in the Western world are from deceased donors. In the last decade, deceased donation rates have reached a plateau as the number of patients with end-stage organ disease has steadily increased, resulting in a large discrepancy between organ supply and demand. Living donor transplantation is one way to decrease this discrepancy. However, living donation is not universally accepted. For instance, living donation rates vary geographically (eg, living donation is more accepted in Asia than in the Western world) and depend on the organ donated (eg, kidney versus liver donation). In this article we will review the ethical principles guiding living donor liver transplantation, with emphasis on justification and safeguards that support the practice of adult-to-adult living donor liver transplantation, the most clinically and ethically challenging type of living organ donation. Our ethical justification will include a presentation of triangular or tripartite equipoise, a framework that aims to balance donor safety, expected recipient outcomes, and need.
Mount Sinai Journal of Medicine A Journal of Translational and Personalized Medicine 03/2012; 79(2):214-22. · 1.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ischemic-type biliary stricture (ITBS) occurs in up to 50% after liver transplantation (LT) from donation after cardiac death (DCD) donors. Thrombus formation in the peribiliary microcirculation is a postulated mechanism. The aim was to describe our experience of tissue plasminogen activator (TPA) administration in DCD-LT. TPA was injected into the donor hepatic artery on the backtable (n = 22). Two recipients developed ITBS including one graft failure. Although excessive postreperfusion bleeding was seen in 14 recipients, the amount of TPA was comparable between those with and without excessive bleeding (6.4 ± 2.8 vs. 6.6 ± 2.8 mg, p = 0.78). However, donor age (41 ± 12 vs. 29 ± 9 years, p = 0.02), donor BMI (26.3 ± 5.5 vs. 21.7 ± 3.6 kg/m(2) , p = 0.03), previous laparotomy (50% vs. 0%, p = 0.02) and lactate after portal reperfusion (6.3 ± 4.6 vs. 2.8 ± 0.9 mmol/L, p = 0.005) were significantly greater in recipients with excessive bleeding. In conclusion, the use of TPA may lower the risk of ITBS-related graft failure in DCD-LT. Excessive bleeding may be related to poor graft quality and previous laparotomy rather than the amount of TPA. Further studies are needed in larger population.
American Journal of Transplantation 12/2010; 10(12):2665-72. · 6.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Blood flow to the liver is partly maintained by the hepatic arterial buffer response (HABR), which is an intrinsic autoregulatory mechanism. Temporary clamping of the portal vein (PV) results in augmentation in hepatic artery flow (augHAF). Portal hyperperfusion impairs HAF due to the HABR in liver transplantation (LT). The aim of this study is to examine the effect of the HABR on biliary anastomotic stricture (BAS).
In 234 cadaveric whole LTs, PV flow (PVF), basal HAF, and augHAF were measured intra-operatively after allograft implantation. All recipients with a vascular complication were excluded. Buffer capacity (BC) was calculated as (augHAF - basal HAF)/PVF to quantify the HABR. Recipients were divided into 2 groups based on their BC: low BC (<0.074; n = 117) or high BC (> or =0.074; n = 117).
Of the 234 recipients, 23 (9.8%) had early BAS (< or =60 days after LT) and 18 (7.7%) had late BAS (>60 days after LT). The incidence of late BAS and bile leakage was similar between the groups; however, the incidence of early BAS in the low BC group was greater than that in the high BC group (15% vs 5.1%; P = .0168). In the multivariate analysis, low BC (P = .0325) and bile leakage (P = .0002) were found to be independent risk factors affecting early BAS.
Recipients with low BC who may have impaired HABR are at greater risk of early BAS after LT. Intraoperative measurements of blood flow help predict the risk of BAS.
Surgery 03/2010; 148(3):582-8. · 3.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Venous outflow obstruction is a rare but potentially lethal complication after orthotopic liver transplantation (OLT) with the "piggyback" technique. Therapeutic options include angioplasty with or without stent placement, surgical reconstruction of the venous anastomosis, and retransplantation. Surgical options are technically very challenging and the outcomes discouraging. We describe here two cases of venous outflow obstruction in recipients of piggyback liver grafts, one involving both the vena cava and hepatic veins and the other affecting only hepatic vein outflow. Both patients were treated successfully with side-to-side cavo-cavostomy using an endovascular (endo-GIA) stapler. This novel technique is fast and effective in resolving the outflow obstruction.
[Show abstract][Hide abstract] ABSTRACT: Hepatocellular carcinoma (HCC) is a highly vascular tumor. Angiogenesis in HCC is mediated at least in part by vascular endothelial growth factor (VEGF), which is expressed in HCC and surrounding cirrhotic tissue. VEGF mediates its angiogenic effects through multiple receptors including VEGF receptor 2 (VEGFr2, KDR/FLK-1), The distribution and clinical significance of VEGFr2 expression in HCC and cirrhotic liver in the setting of liver transplantation have not been tissue site specific evaluated. Immunohistochemical staining for VEGFr2 was performed in 78 liver explants from patients with HCC undergoing liver transplantation. VEGFr2 levels in HCC were significantly increased compared to adjacent, nontumorous cirrhotic liver areas (P < 0.05). VEGFr2 levels were significantly higher in the veins and sinusoids of poorly differentiated tumors (P < 0.05). VEGFr2 levels in the tumors were not significantly different between patients within and beyond Milan criteria. However, VEGFr2 levels were significantly higher in the arteries of non-tumorous liver in patients beyond Milan criteria (P < 0.05). No significant association was observed between VEGFr2 levels and the presence of tumor vascular invasion or recurrence post transplantation. These findings suggest that VEGFr2 up-regulation is a feature of poor differentiation and tumor progression. Further investigation is needed to assess the value of angiogenesis modulation in preventing tumor formation and/or progression in cirrhotic patients.
[Show abstract][Hide abstract] ABSTRACT: Due to the shortage of available cadaveric organs, living donor liver transplantation (LDLT) has been recently applied extensively in adults. The use of the left lobe should be encouraged because of donor safety, but frequently the metabolic requirements of severely cirrhotic patients are great and subsequent graft dysfunction is encountered after transplantation. The importance of increased portal inflow to the graft in previously severely cirrhotic patients and other hemodynamic changes in LDLT using left lobes are still under debate, as are the surgical modulations to correct them. In this study, we have reported an initial series of adult-to-adult LDLT using left lobes, underlining the hemodynamic changes encountered during the transplant and the surgical modulations we applied to correct them.
Eight adult recipients underwent left lobe liver transplantation from living donors. Portal vein pressure and central venous pressure were measured before and after surgical modulation.
We encountered four cases of small-for-size syndrome. Two patients were retransplanted; the other two died. Seventy-five percent of our recipients survived and 50% did not require further surgery.
Surgical portal inflow modulation should be considered in cases of left lobe liver transplantation between adults.
[Show abstract][Hide abstract] ABSTRACT: Abdominal wall closure after intestinal transplantation in adult patients can be a difficult procedure. The main possibility offered by international experience is the use of myocutaneous flaps and abdominal wall transplantation. We report our experience in intestinal/multivisceral transplantation, including four difficult cases among 27 adult transplant recipients. Three patients underwent prosthetic mesh alone and one, a myocutaneous flap for abdominal closure after primary mesh positioning. We selected a mesh with a structure that allowed us to close the abdomen without creating adhesions and, at the same time, stimulating tissue repair. Two patients experienced local mesh infection, which has been kept under clinical control by antibiotics and daily medications till neoabdominal wall formation. The mesh was then removed. Another patient underwent mesh substitution for a suspicious fever. The last patient had mesh as a bridge for a subsequent myocutaneous flap from the thigh. All patients are in good health with well-functioning grafts and no need for parenteral nutrition. No enterocutaneous fistulae were detected.