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Arteriovenous fistula (AVF) aneurysms are a chronic complication which can be disfiguring, painful, and can rupture. Here, we compare the outcomes between three different methods of AVF aneurysm repair.One-way ANOVA, Chi-square, and Fisher Exact analyses were used to compare demographics. Multivariate logistic regression compared outcomes. Kaplan-Meier estimate illustrated long-term fistula patency.There were no differences between demographics in the aneurysmorrhaphy, end-to-end anastomosis, and synthetic graft groups. The odds of patients who received graft repair losing primary patency within one year compared to the aneurysmorrhaphy group was 3.5 (p = 0.025). Graft repair patients were 6.7 times more likely to develop an infection compared to aneurysmorrhaphy (p = 0.014). Synthetic grafts also exhibited accelerated rates of complete access loss compared to autogenous methods (p = 0.034).Graft repair of AVF aneurysms results in higher rates of infection and decreased primary and ultimate patency compared to autogenous repair techniques. Therefore, synthetic grafts should be avoided whenever possible.

Positive resection margins are associated with worse survival after surgery for adrenocortical carcinoma (ACC). We aimed to identify risk factors for positive margins post-resection.The NCDB was queried for ACC patients from 2006 to 2015. Patients with positive versus negative resection margins post-surgery were compared using Chi-square tests. Survival based on adjuvant treatment was assessed using Kaplan-Meier curves.1,973 patients with ACC were identified, 217 (11.0%) with positive margins. Multivariable analysis identified extra-adrenal extension (HR 4.92, p 0.001), lymph node metastases (HR 2.64, p = 0.001), and distant metastases (HR 1.53, p = 0.03) as risk factors for positive margins. No significant difference in margin status existed between patients who had an open versus minimally invasive procedure (p = 0.6). Positive margin patients receiving adjuvant radiation (p = 0.007) or combined chemo-radiation (p = 0.001) had the longest survival.No modifiable risk factors were identified, but patients with positive margins receiving adjuvant radiation or chemo-radiation had the longest survival.

Many current guidelines recommend nonoperative management for pancreatic neuroendocrine tumors2 cm. The objective of this study was to evaluate the utilization and outcomes of resection for these pancreatic neuroendocrine tumors in the United States.Using the National Cancer Database (2004-2014), 3,243 cases of T1 (≤2.0 cm) pancreatic neuroendocrine tumors were identified. Additional patient and tumor characteristics were examined. Multivariate models were used to identify factors that predicted resection and to assess patient survival after resection.75% of pancreatic neuroendocrine tumors measuring 0 to 1.0 cm and 80% of pancreatic neuroendocrine tumors measuring1.0 and ≤2.0 cm were resected. Eighty-four pancreatic neuroendocrine tumors were functional, of which 82% were resected. Variables influencing resection included positive lymph nodes, tumor in body or tail of pancreas, well or moderately differentiated tumors, and resection at academic medical centers (odds ratio 1.5-4.9). When controlling for other variables, patients with pancreatic neuroendocrine tumors 1 to 2 cm who underwent resection had a prolonged 5-year survival rate (hazard ratio 0.51, confidence interval 0.34-0.75) when compared with those who did not undergo resection. This survival benefit of resection was not found for pancreatic neuroendocrine tumors 0 to 1 cm (hazard ratio = 0.63, confidence interval 0.36-1.11).Contrary to many current recommendations, most patients with pancreatic neuroendocrine tumors ≤2.0 cm undergo surgical resection in the United States. A survival benefit was found for resection of pancreatic neuroendocrine tumors 1 to 2 cm, suggesting that current recommendations should perhaps be revised.

Background After portal vein ligation of 1 side of the liver, the other side regenerates at a slow rate. This slow growth may be accelerated to rapid growth by adding a transection between the 2 sides, i.e., performing portal vein ligation and parenchymal transection. We found that in patients undergoing portal vein ligation and parenchymal transection, portal vein hyperflow in the regenerating liver causes a significant reduction of arterial flow due to the hepatic arterial buffer response. We postulated that the reduction of arterial flow induces hypoxia in the regenerating liver and used a rat model to assess hypoxia and its impact on kinetic growth. Methods A rat model of rapid (portal vein ligation and parenchymal transection) and slow regeneration (portal vein ligation) was established. Portal vein flow and pressure data were collected. Liver regeneration was assessed in rats using computed tomography, proliferation with Ki-67, and hypoxia with pimonidazole and HIF-1α staining. Results The rat model confirmed acceleration of regeneration in portal vein ligation and parenchymal transection as well as the portal vein hyperflow seen in patients. Additionally, tissue hypoxia was observed after portal vein ligation and parenchymal transection, while little hypoxia staining was detected after portal vein ligation. To determine if hypoxia is a consequence or an inciting stimulus of rapid liver regeneration, we used a prolyl-hydroxylase blocker to activate hypoxia signaling pathways in the slow model. This clearly accelerated slow to rapid liver regeneration. Inversely, abrogation of hypoxia led to a blunting of rapid growth to slow growth. The topical application of prolyl-hydroxylase inhibitors on livers in rats induced spontaneous areas of regeneration. Conclusion This study shows that pharmacologically induced hypoxic signaling accelerates liver regeneration similar to portal vein ligation and parenchymal transection. Hypoxia is likely an accelerator of liver regeneration. Also, prolyl-hydroxylase inhibitors may be used to enhance liver regeneration pharmaceutically.

Hepatic cysts encompass a spectrum of clinical etiologies but most are benign, occur rarely, and are usually asymptomatic. Symptomatic cysts may present with abdominal pain, hemorrhage, obstructive jaundice, or a consumptive coagulopathy. The optimal surgical management of hepatic cysts varies depending on the size and location of the lesion, but includes laparoscopic cyst fenestration,1 formal resection, enucleation, as well as liver transplantation.

Type 1 primary hyperoxaluria (PH1) causes renal failure, for which isolated kidney transplantation (KT) is usually unsuccessful treatment due to early oxalate stone recurrence. Although hepatectomy and liver transplantation (LT) corrects PH1 enzymatic defect, simultaneous auxiliary partial liver transplantation (APLT) and KT have been suggested as an alternative approach. APLT advantages include preservation of the donor pool and retention of native liver function in the event of liver graft loss. However, APLT relative mass may be inadequate to correct the defect. We here report the first case of native portal vein embolization (PVE) to increase APLT to native liver mass ratio (APLT/NLM-R). Following initial combined APLT-KT, both allografts functioned well, but oxalate plasma levels did not normalize. We postulated the inadequate APLT/NLM-R could be corrected by trans-hepatic native PVE. The resulting increased APLT/NLM-R decreased serum oxalate to normal levels within 1 month following PVE. We conclude that persistently elevated oxalate levels after combined APLT-KT for PH1 treatment, results from inadequate relative functional capacity. This can be reversed by partial native PVE to decrease portal flow to the native liver. This approach might be applicable to other scenarios where partial grafts have been transplanted to replace native liver function.

Purpose: Ureteroneocystostomy (UCN) is the most widely used urinary reconstruction technique during kidney transplantation. Disadvantages of this technique include a high incidence of hematuria and reflux, plus the potential for obstruction resulting from distal ureteral fibrosis. Pyeloureterostomy (PU) avoids these complications but increases the technical complexity. Methods: Between January 1990 and December 2005, 1066 adults patients underwent kidney transplantations; 768 patients (72.1%) had urinary reconstruction by PU and 298 (27.9%) underwent UNC. Results: Patients in the PU group underwent simultaneous ipsilateral native nephrectomy. The operative time was longer in the PU group compared with the UNC group: 210 � 36 min versus 182 � 24 min (P < 0.001). Overall surgical complications in the PU group were comparable to those in the UNC group (9.5% versus 12.3%). The urinary complication rate was also comparable in both groups: 3.2% (25 of 768) in the PU group and 5% (15 of 298) in the UNC group. However, urinary obstruction comprised 60% of urinary complications in the UNC group, compared with 32% in the PU group (P < 0.01). We treated most urinary complications non-operatively. However, 24% of patients (six of 25) in the PU group needed operative intervention or revision for ureteral reconstruction, compared with 46.6% (seven of 15) in the UNC group (P < 0.01). Conclusions: Pyeloureterostomy is a safe and effective method for urinary tract reconstruction in renal transplantation. Pyeloureterostomy should be part of every transplant surgeon’s armamentarium.

Background The shortage in donor livers has led to increased use of allografts derived from donation after cardiac death (DCD). The compromised viability in these livers leads to inferior post-transplantation allograft function and survival compared with donation after brain death (DBD) donor grafts. In this study, we reconditioned DCD livers using an optimized normothermic machine perfusion system. Methods Livers from 12 Yorkshire pigs (20–30 kg) were subjected to either 0 min (WI-0 group, n = 6) or 60 min (WI-60 group, n = 6) of warm ischemia and 2 h of cold storage in UW solution, followed by 4 h of oxygenated sanguineous normothermic machine perfusion. Liver viability and metabolic function were analyzed hourly. Results Warm ischemic livers showed elevated transaminase levels and reduced ATP concentration. After the start of machine perfusion, transaminase levels stabilized and there was recovery of tissue ATP, coinciding with an increase in bile production. These parameters reached comparable levels to the control group after 1 h of machine perfusion. Histology and gross morphology confirmed recovery of the ischemic allografts. Conclusion Our data demonstrate that metabolic and functional parameters of livers with extended warm ischemic time (60 min) can be significantly improved using normothermic machine perfusion. We hereby compound the existing body of evidence that machine perfusion is a viable solution for reconditioning marginal organs.

BackgroundMany patients on hemodialysis do not have adequate anatomy for native arteriovenous fistulas. In these patients, synthetic conduits remain an alternative option for permanent hemodialysis access. We sought to compare the standard cuffed expanded polytetrafluoroethylene (ePTFE) graft with the bovine carotid artery (BCA) graft.MethodsThis was a prospective, randomized controlled trial that was set in an academic medical center. We enrolled 26 patients in the BCA group and 27 patients in the ePTFE group. Primary, assisted primary, and secondary patency were calculated using the Kaplan-Meier method. Complications were monitored and are reported.ResultsAlthough there was no significant difference in secondary patency rates, primary and assisted primary patency rates were significantly higher in BCA than in the ePTFE grafts (60.5% vs 10.1% and 60.5% vs 20.8% at 1 year, respectively). The BCA graft survival advantage was most profound in the upper arm grafts with significantly higher primary and assisted patency rates (P < .0001 and .0005, respectively). The total number of interventions (upper arm grafts) and total number of angioplasties (overall and upper arm) required to maintain patency were significantly fewer in the BCA group. The most common complication was graft thrombosis which occurred 0.34 ± 0.09 times per patient year in the BCA group compared to 0.77 ± 0.16 times per patient year in the ePTFE group, P = .01.ConclusionThe BCA graft is an excellent option for patients on hemodialysis that are not suitable for native arteriovenous fistulas, as these grafts required fewer interventions than the ePTFE grafts to maintain patency.

Introduction The gold standard in organ preservation is static cold storage (SCS) using University of Wisconsin solution (UW). Although it is well-known that there is a finite limit to SCS preservation, and that there is a correlation between the adenosine triphosphate (ATP) levels and organ function post-preservation, a quantitative relationship has not been established, which is important in understanding the fundamental limitations to preservation, minimizing cold ischemic injury, and hence maximizing use of the donor organ pool. Aim This study determines the time limits of cellular viability and metabolic function during SCS, and characterizes the relationship between cellular viability and energetic state using clinically relevant techniques in organ preservation. Methods Rat livers were procured and stored using conventional storage in UW solution at 4°C. Viability was assessed by determining the amount of viable hepatocytes and intracellular ATP content after 0, 24, 48, 72, and 120 hours of storage. Results Numbers of viable hepatocytes that were isolated from these livers decreased steadily during SCS. After 5 days, viable hepatocytes decreased from 25.95 × 10 6 to 0.87 × 10 6 cells/gram tissue. Intracellular ATP content decreased from 9.63 to 0.93 moles/g tissue. Statistical analysis of variance established a linear relation for both parameters as a function of time ( P Conclusion The linear correlation between hepatocyte viability, ATP content, and storage time suggests a shared physiological foundation. These findings confirm ATP as direct predictor for organ quality in the context of liver preservation, which will aid quantitative assessment of donor organs for various applications.

Donors after cardiac death present a significant pool of untapped organs for transplantation, and use of machine perfusion strategies has been an active focus area in experimental transplantation. However, despite 2 decades of research, a gold standard has yet to emerge for machine perfusion systems and protocols. Whole blood reperfusion has been used as a surrogate for organ transplantation, especially as a model for the short-term response posttransplantation, and for optimization of perfusion systems. Although it is known that there is a strong correlation between liver function in whole-blood reperfusion and survival, the exact nature of these correlations, and to what extent they can be considered as an indicator of viability for transplantation/recipient survival, remain unclear. In this work, we demonstrate that diluted whole-blood reperfusion can be used as a direct model for transplantation of ischemic rat liver grafts. Specifically, we show that recipient survival can be predicted based simply on the value of alanine aminotransferase during perfusion, providing quantitative criteria of viability for use in this animal model. These results indicate that in the rat model graft survival is highly correlated with hepatocellular damage.

There is a paucity of data on long-term outcomes of older kidney recipients. Our aim was to compare the early and long-term outcomes of deceased donor kidney transplantation in patients agedor=60 years with outcomes in younger recipients.From 1998 to 2005, we performed 271 deceased donor kidney transplants. There were 76 recipients (28.1%)60 years old. Older candidates were carefully selected based on their physiologic, cardiac, and performance status. Demographic data, including clinical characteristics, early complications, mortality, and patient and graft survival rates, were collected and analyzed.Older patients had comparable perioperative mortality and morbidity, incidence of delayed graft function (DGF), length of stay, and readmissions compared with younger patients. The rates of acute rejection and major infections were also comparable between the 2 study groups. Among older recipients, 25/76 (32.1%) patients received extended criteria donor kidneys compared with only 35/195 (17.9%) of younger patients (P.001). Nevertheless, equivalent 1-, 3-, and 5-year allograft survival rates were observed in elderly and young patients; 91.5% versus, 92.5%, 78.5% versus 81.9%, and 75.6% versus 78.5%, respectively. Overall patient survival was also comparable in both groups.Kidney transplantation in appropriately selected elderly recipients provides equivalent outcomes compared with those observed in younger patients. These observations support the notion that older recipients should not lose access to deceased donor kidney transplantation in the effort to achieve a perceived gain in social utility.

Organ transplantation is increasingly available to the thousands of patients who suffer from end-organ failure. There has been an attendant increase in demand for living donor participation. This combined with a bioethical focus on autonomy increases the burden of decision on donor candidates. The authors review the history of living donor participation in organ transplantation and explore the psychological dynamics of the clinical encounter between donor and transplant surgeon. The field of communication psychology lends to the understanding of coercion and to the importance of donors possessing a status of patient-hood in the classical Hippocratic condition.

The optimal preservation temperature for liver allografts is unknown. We evaluated the effect of small differences in preservation temperature, 5 degrees C vs 0 degrees C, on outcome of prolonged preservation. Livers of Wistar rats were preserved at these temperatures in UW solution for 40 h. Function was studied during reperfusion on the isolated perfused rat liver system at 37 degrees C. To compare the effects of a small reduction in temperature with known beneficial strategies, the effects of including antiproteases and periodic flushing of the graft with UW solution during cold preservation at 5 degrees C were also studied. Aspartate transaminase (AST) and alanine transaminase release after 4 h of reperfusion were much higher in the livers stored at 5 than at 0 degrees C (P < 0.0005). Addition of antiproteases to the preservation solution or periodic flushing reduced AST release but neither treatment at 5 degrees C was as good as simple storage at 0 degrees C. Cumulative bile production after 4 h of reperfusion was significantly greater in the 0 degrees C preserved group than in liver at 5 degrees C or 5 degrees C with periodic flushing. The addition of antiproteases resulted in slightly increased bile production (not significant). Platelets and WBCs in the perfusate decreased during reperfusion. This effect was more pronounced in the 5 degrees C preserved livers than in those stored at 0 degrees C. Antiproteases in the preservation solution appeared to inhibit platelet and WBC loss. Perfusate flow was significantly higher in the 0 degrees C group. We conclude that small differences in preservation temperature even at these low temperatures are important in postreperfusion liver function.