End-to-end anastomosis as a superior repair type to prevent recurrence of arteriovenous fistula aneurysms and improve patency outcomes.

BACKGROUND: Arteriovenous fistulae (AVF) complicated by aneurysms are repaired through several mechanisms. Little is known about risk factors for aneurysm recurrence or the efficacy of subsequent repair of recurring aneurysms. METHODS: About 291 patients underwent AVF aneurysm repair between 2009 and 2019 at a large urban medical center. Patients who underwent staged repair, had a primary graft with pseudoaneurysm, were status-post kidney transplant, or using other dialysis access at the time of repair were excluded. One hundred sixty-two patients were included in the study, of which 52 developed a secondary aneurysm. Chi-square and t-test analyses were used to compare demographics. Multivariate logistic regression was used to examine independent risk factors for aneurysm recurrence. Of the 52 patients with recurrent aneurysms, 41 were repaired again. Patency was examined for each group 1 year postoperatively. RESULTS: Patients without secondary aneurysms were more likely to have a Charlson Comorbidity Index score ⩾5 (p = 0.045). Males were 2.8 times more likely to develop a secondary aneurysm compared to females (p = 0.023). Patients who underwent elective compared to emergent or urgent surgery for primary aneurysms were significantly less likely to recur (OR = 0.222; p = 0.016). Primary aneurysms repaired by end-to-end anastomosis, compared to aneurysmorrhaphy or graft, were significantly less likely to recur (OR = 0.239; p = 0.041). Among patients with secondary aneurysms, those repaired via end-to-end anastomosis had a significantly higher primary patency rate 1 year postoperatively (p = 0.024). Secondary aneurysm repairs exhibited 1-year primary and secondary patency rates of 51.2% and 82.9%, respectively. CONCLUSIONS: End-to-end anastomosis reduces risk of recurrence and demonstrates superior patency rates when repairing recurrent aneurysms. It remains unclear why some patients are prone to aneurysm recurrence, however continued attempts to repair existing vascular access are proven to be successful.

Graft repair of arteriovenous fistula aneurysms is associated with decreased long-term patency.

INTRODUCTION: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Association between Preoperative Steroids and Outcomes in Patients Undergoing Pancreaticoduodenectomy using the National Surgical Quality Improvement Program.

BACKGROUND: A national study analyzing the association between preoperative steroid use and outcomes after pancreatic resections is lacking. The purpose of this study is to evaluate the association between preoperative steroids and outcomes after pancreaticoduodenectomy using a national database. MATERIALS AND METHODS: A retrospective analysis of patients undergoing pancreaticoduodenectomy was performed using the National Surgical Quality Improvement Program (NSQIP) database (2014-2019). In addition, we utilized propensity score matching to compare patients on preoperative steroids to those who were not. Outcomes measured included 30-day complications and mortality, need for readmission, a prolonged hospital length of stay, delayed gastric emptying, and pancreatic fistula. RESULTS: After propensity score matching, there were 438 patients in the steroid group and 876 patients in the no steroid group. There was no difference in pancreatic fistula (23.8% vs. 21.7%; p-0.3), delayed gastric emptying (21.1% vs.20.1%; p-0.06), major complications (31.8% vs. 30.1%; p-0.1), and mortality (3.5% vs. 3.2%; p-0.6) between the two groups. CONCLUSION: Glucocorticoids did not reduce the incidence of overall complications, postoperative fistula, and delayed gastric emptying following pancreaticoduodenectomy.

Successful treatment of refractory hypertension with bilateral nephrectomy in a patient with chronic kidney disease stage 3.

We present a case of life-threatening refractory hypertension (rHTN) in a patient with stage 3b chronic kidney disease that was unresponsive to open surgical renal denervation (RDN) but responded to bilateral nephrectomy (BLN). Both RDN and BLN reduce the increased sympathetic activation in rHTN. However, RDN has yet to show reductions in blood pressure adequate for the average patient with rHTN, and BLN has thus far been reserved for patients with preexisting end-stage kidney disease (ESKD). Our case suggests that there are patients with rHTN that warrant consideration of BLN prior to developing ESKD.

Can Donor-Derived Cell-Free DNA Detect Graft-Versus-Host Disease in Solid Organ Transplantation: A Case Report.

Graft-versus-host disease (GVHD) is a rare complication after solid organ transplant. We present a case of GVHD after simultaneous pancreas kidney transplant. The patient was diagnosed with a cutaneous biopsy after developing the classic symptoms of maculopapular rash, diarrhea, and pancytopenia. However, this patient had unexplained elevations in donor-derived cell-free DNA (dd-cfDNA) for months before the onset of GVHD symptoms. We hypothesize that GVHD may be associated with elevated dd-cfDNA as a result of massive donor lymphocyte proliferation and turnover. Further investigation is warranted because earlier diagnosis and treatment could improve outcomes in an otherwise lethal disease.

Heat Stroke as a Cause of Liver Failure and Evaluation of Liver Transplant.

Heat stroke is a multiple organ dysfunction syndrome of poorly understood pathogenesis. Exertional heat stroke with acute liver failure is a rarely reported condition. Liver transplant has been recommended as treatment in cases of severe liver dysfunction; however, there are only 5 described cases of long-term survival after this procedure in patients with heat stroke. Here, we present 2 cases of young athletes who developed heat stroke. Both patients developed acute liver failure and were listed for liver transplant. Liver function tests of one patient improved, and he was discharged on postoperative day 13. The other patient showed no signs of improvement and liver biopsy showed massive necrosis. The patient underwent combined kidney-liver transplant and was discharged on postoperative day 17. After a follow-up of longer than 6 years, both patients are doing well with normal liver function and no neurologic sequelae. We also reviewed all published cases of hepatic failure associated with heat stroke and found 9 published cases of liver transplant for heat stroke in the English literature. Conservative management appears to be justified in heat stroke-associated liver failure, even in the presence of accepted criteria for emergency liver transplant. If the liver does not show signs of recovery and hepatic decompensation progresses, liver transplant should be performed.

Strategic Planning and Essential Steps for Establishing a Uterine Transplant and Rehabilitation Program: From Idea to Reality.

UTx is performed to address absolute uterine infertility in the presence of uterine agenesis, a nonfunctional uterus, or after a prior hysterectomy. After the initial success of UTx resulting in a livebirth (2014) in Sweden, there are over 70 reported UTx surgeries resulting in more than 40 livebirths worldwide. Currently, UTx has been performed in over 10 countries. As UTx is transitioning from an "experimental procedure" to a clinical option, an increasing number of centers may contemplate a UTx program. This article discusses essential steps for establishment of a successful UTx program. These principles may be implemented in cis- and transgender UTx candidates.

National Trends in Cholecystectomy and Endoscopic Retrograde Cholangiopancreatography During Index Hospitalization for Mild Gallstone Pancreatitis.

BACKGROUND: Guidelines call for cholecystectomy during the index hospitalization for patients with gallstone pancreatitis. Therefore, the study sought to determine the trends for cholecystectomy and Endoscopic Retrograde Cholangiopancreatography (ERCP) for mild gallstone pancreatitis. METHODS: A retrospective analysis of the 2010-2018 Nationwide Readmission Database (NRD) was performed to identify patients with mild gallstone pancreatitis. The primary aim was to identify the trends in the use of cholecystectomy in these patients, and the secondary aim was to assess if ERCP alone was protective against readmission. RESULTS: A total of 510,470 patients with mild gallstone pancreatitis were identified. There has been an increasing trend in ERCP use (25% in 2018 vs. 22% in 2010; p-0.001) and a decline in cholecystectomy (37% in 2018 vs. 46% in 2010; p-0.001) prior to discharge. Multivariate analysis revealed higher 30-day readmission for patients who underwent ERCP without cholecystectomy (odds ratio1.3; 95% confidence interval, 1.1-3.5) during the index admission. CONCLUSIONS: There has been a decline in the use of cholecystectomy during index hospitalization for mild gallstone pancreatitis. In addition, ERCP was not protective against 30-day readmission from mild gallstone pancreatitis.

Identification of Novel Therapeutic Targets for Fibrolamellar Carcinoma Using Patient-Derived Xenografts and Direct-from-Patient Screening.

To repurpose therapeutics for fibrolamellar carcinoma (FLC), we developed and validated patient-derived xenografts (PDX) from surgical resections. Most agents used clinically and inhibitors of oncogenes overexpressed in FLC showed little efficacy on PDX. A high-throughput functional drug screen found primary and metastatic FLC were vulnerable to clinically available inhibitors of TOPO1 and HDAC and to napabucasin. Napabucasin's efficacy was mediated through reactive oxygen species and inhibition of translation initiation, and specific inhibition of eIF4A was effective. The sensitivity of each PDX line inversely correlated with expression of the antiapoptotic protein Bcl-xL, and inhibition of Bcl-xL synergized with other drugs. Screening directly on cells dissociated from patient resections validated these results. This demonstrates that a direct functional screen on patient tumors provides therapeutically informative data within a clinically useful time frame. Identifying these novel therapeutic targets and combination therapies is an urgent need, as effective therapeutics for FLC are currently unavailable. SIGNIFICANCE: Therapeutics informed by genomics have not yielded effective therapies for FLC. A functional screen identified TOPO1, HDAC inhibitors, and napabucasin as efficacious and synergistic with inhibition of Bcl-xL. Validation on cells dissociated directly from patient tumors demonstrates the ability for functional precision medicine in a solid tumor.This article is highlighted in the In This Issue feature, p. 2355.

Comparative incidence and outcomes of COVID-19 in kidney or kidney-pancreas transplant recipients versus kidney or kidney-pancreas waitlisted patients: A single-center study.

BACKGROUND: COVID-19 epidemiologic studies comparing immunosuppressed and immunocompetent patients may provide insight into the impact of immunosuppressants on outcomes. METHODS: In this retrospective cohort study, we assembled kidney or kidney-pancreas transplant recipients who underwent transplant from January 1, 2010, to June 30, 2020, and kidney or kidney-pancreas waitlisted patients who were ever on the waitlist from January 1, 2019, to June 30, 2020. We identified laboratory-confirmed COVID-19 until January 31, 2021, and tracked its outcomes by leveraging informatics infrastructure developed for an outcomes research network. RESULTS: COVID-19 was identified in 62 of 887 kidney or kidney-pancreas transplant recipients and 20 of 434 kidney or kidney-pancreas waitlisted patients (7.0% vs. 4.6%, p = .092). Of these patients with COVID-19, hospitalization occurred in 48 of 62 transplant recipients and 8 of 20 waitlisted patients (77% vs. 40%, p = .002); intensive care unit admission occurred in 18 of 62 transplant recipients and 2 of 20 waitlisted patients (29% vs. 10%, p = .085); and 7 transplant recipients were mechanically ventilated and died, whereas no waitlisted patients were mechanically ventilated or died (11% vs. 0%, p = .116). CONCLUSIONS: Our study provides single-center data and an informatics approach that can be used to inform the design of multicenter studies.

Economic evaluation of suture versus clip anastomosis in arteriovenous fistula creation.

OBJECTIVE: Techniques such as the use of nonpenetrating vascular clips for arteriovenous fistula (AVF) anastomotic creation have been developed in an effort to reduce fistula-related complications. However, the outcomes data for the use of clips have remained equivocal, and the cost evaluations to support their use have been largely theoretical. Therefore, the present study aimed to determine both the clinical and the cost outcomes of AVFs created with nonpenetrating vascular clips compared with the continuous suture technique during a 10-year period at a single institution. METHODS: All patients undergoing AVF creation in the upper extremity from 2009 through 2018 were retrospectively analyzed. The patient demographics and AVF outcomes were collected and compared stratified by the surgical technique used. A cost analysis was performed of a subgroup of patients from 2013 to 2018. RESULTS: During the 10-year study period, 916 AVFs were created (79% using the continuous suture technique and 21% using nonpenetrating vascular clips). Patient demographics and comorbid conditions did not differ between the two groups, and no differences were present in maturation, primary patency, assisted primary patency, or complication rates between the two groups at 1 year. The suture group had a shorter time to maturation (4.3 months vs 5.5 months; P < .01) and improved secondary patency compared with the clip group (77.13% vs 69.59%; P = .03) The cost analysis of the procedures revealed a significant difference in direct costs (suture, $1389.26 vs clip, $1716.51; P < .01) and contribution margin (suture, $1770.19 vs clip, $1128.36; P < .01) for the two groups. CONCLUSIONS: Both suture and clip techniques in AVF creation demonstrated equivalent rates of maturation, primary patency, assisted primary patency, and complications at 1 year with higher expense associated with the use of clips. Thus, in an effort to reduce the economic burden of healthcare in the United States, the findings from the present study support the preferential use of the standard polypropylene suture technique when creating upper extremity AVFs.

Should Pre-Transplant Hemoglobin A1c Be Used to Predict Post-Transplant Compliance in End-Stage Renal Disease Patients Undergoing Kidney Transplantation?

BACKGROUND Patient compliance with immunosuppressive therapy after transplant has impacts on both graft and patient outcomes. For diabetic end-stage renal disease (ESRD) patients who are undergoing evaluation for kidney transplantation in our program, hemoglobin A1c (HbA1c) level of >10% is used as a flag that the patient may be at risk for noncompliance and that more comprehensive psychosocial screening is needed prior to transplant. We evaluated the association between pre-transplant HbA1c level and post-transplant compliance, as no study to date has looked at this in the transplant population. MATERIAL AND METHODS The charts of 392 patients who received a kidney transplant at a single institution between July 2008 and June 2012 were retrospectively reviewed. One hundred and sixty-five diabetic patients who received a kidney transplant alone were included in the final analysis. Our predictive variable was HbA1c level greater than 7.7% based on previous reports in the diabetic population. Outcome measures were graft survival, rejection episodes, unexplained low immunosuppressant levels, and documented noncompliance. RESULTS There were no statistically significant differences between the HbA1c groups of ≤7.7% and >7.7% in outcomes of failed grafts (22.0% and 17.8%, p=0.2), rejection episodes (15.0% and 6.7%, p=0.3), unexplained low immunosuppressant level (46.6% and 37.9%, p=0.3), and documented noncompliance (25.0% and 16.7%, p=0.4). CONCLUSIONS In diabetic ESRD patients selected for renal transplantation, elevated pre-transplant HbA1c levels, defined as HbA1c >7.7%, are not predictive of post-transplant medication compliance. We advocate that this group of patients should not be denied transplant solely on their elevated pre-transplant HbA1c.

Risk factors associated with positive resection margins in patients with adrenocortical carcinoma.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: No modifiable risk factors were identified, but patients with positive margins receiving adjuvant radiation or chemo-radiation had the longest survival.

Operative resection in early stage pancreatic neuroendocrine tumors in the United States: Are we over- or undertreating patients?

BACKGROUND: Many current guidelines recommend nonoperative management for pancreatic neuroendocrine tumors <2 cm. The objective of this study was to evaluate the utilization and outcomes of resection for these pancreatic neuroendocrine tumors in the United States. METHODS: 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. RESULTS: 75% of pancreatic neuroendocrine tumors measuring 0 to 1.0 cm and 80% of pancreatic neuroendocrine tumors measuring >1.0 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). CONCLUSIONS: 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.

National Treatment Practice for Adrenocortical Carcinoma: Have They Changed and Have We Made Any Progress?

BACKGROUND: Adrenocortical carcinoma (ACC) is a rare malignancy with a dismal prognosis. Two landmark trials published in 2007 and 2012 showed efficacy for adjuvant mitotane in resectable ACC and etoposide/doxorubicin/cisplatin plus mitotane for unresectable ACC, respectively. In this study, we used the National Cancer Database to examine whether treatment patterns and outcomes changed after these trials. METHODS: The National Cancer Database was used to examine treatment patterns and survival in patients diagnosed with ACC from 2006 to 2015. Treatment modalities were compared within that group and with a historical cohort (1985 to 2005). χ2 tests were performed, and Cox proportional hazards models were created. RESULTS: From 2006 to 2015, 2752 patients were included; 38% of patients (1042) underwent surgery alone, and 31% (859) underwent surgery with adjuvant therapy. Overall 5-year survival rates for all stages after resection were 43% (median, 41 months) in the contemporary cohort and 39% (median, 32 months) in the historical cohort. After 2007, patients who underwent surgery were more likely to receive adjuvant chemotherapy (P = 0.005), and 5-year survival with adjuvant chemotherapy improved (41% vs 25%; P = 0.02). However, survival did not improve in patients with unresectable tumors after 2011 compared with 2006 to 2011 (P = 0.79). Older age, tumor size ≥10 cm, distant metastases, and positive margins were associated with lower survival after resection (hazard ratio range: 1.39 to 3.09; P < 0.03). CONCLUSIONS: Since 2007, adjuvant therapy has been used more frequently in patients with resected ACC, and survival for these patients has improved but remains low. More effective systemic therapies for patients with ACC, especially those in advanced stages, are desperately needed.

Primary Tumor Site Affects Survival in Patients with Gastroenteropancreatic and Neuroendocrine Liver Metastases.

BACKGROUND: Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are commonly present with metastatic disease, and the liver is the most frequent metastatic site. Herein, we studied whether primary tumor site affects survival in patients with GEP-NETs and liver metastases (NELM). As a secondary endpoint, we studied whether extrahepatic disease and surgical resection impact survival in this patient population. METHODS: Patients with NELM diagnosed from 2006 to 2014 were identified from the National Cancer Database. Kaplan-Meier curves and nested Cox proportional hazards were used to assess variables associated with survival. RESULTS: 2947 patients with well- or moderately differentiated GEP-NETs and NELM met the inclusion criteria for this study. Patients with small bowel NETs survived the longest of all GEP-NETs with NELM (median not reached). Rectal and gastric NETs with NELM had the shortest survival (median 31 months). Patients with extrahepatic metastases who underwent any operation survived longer than those managed nonoperatively (median survival 38.7 months vs. 18.6 months, p = 0.01). On multivariable analysis, operations on the primary tumor and distant metastatic site (HR 0.23-0.43 vs. no surgery), treatment at an academic/research hospital, Charlson comorbidity index of 0, no extrahepatic metastases, and younger age were associated with prolonged survival (p < 0.01). CONCLUSIONS: Primary tumor site affects survival in patients with GEP-NETs and NELM. Surgical resection seems beneficial for all GEP-NETs with NELM, even in the presence of extrahepatic metastases.

Do All Abdominal Neuroendocrine Tumors Require Extended Postoperative VTE Prophylaxis? A NSQIP Analysis.

BACKGROUND: Venous thromboembolism (VTE) occurs at high incidence in abdominal cancer surgery; therefore, a 4-week postoperative VTE prophylaxis is advocated. However, most patients with neuroendocrine tumors (NETs) have more favorable prognoses. This study aimed to determine the incidence of VTE in patients with abdominal NETs, compare these rates to other abdominal malignancies, and identify VTE risk factors. METHODS: The ACS-NSQIP database was queried to identify patients with abdominal NETs and other abdominal malignancies who underwent surgery from 2008 to 2015. A 30-day postoperative VTE incidence for each group was compared. Univariable and multivariable analyses were used to identify VTE risk factors. RESULTS: Of the 7226 operations for patients with benign (2154) and malignant (5072) abdominal NETs, 144 patients experienced a VTE without significant differences between groups. Subgroup analysis revealed a spectrum of VTE rates. Compared to VTE rates of other abdominal malignancies, patients with benign (1.1% vs. 2.4%, p < 0.001) or malignant (1.7% vs. 2.4%, p < 0.001) non-pancreatic abdominal NETs had significantly lower rates, malignant pancreatic NETs (PNETs) (3.4% vs. 2.4%, p = 0.03) had significantly higher rates, and benign PNETs (3.2% vs. 2.4%, p = 0.21) had comparable rates. Multivariable analysis identified pre-operative albumin (p < 0.001), bleeding disorders (p < 0.001), operative time (p < 0.001), and having a PNET (p = 0.04) as risk factors for VTE in abdominal NET patients. CONCLUSION: Routine extended VTE prophylaxis after surgery may be necessary in PNETs, but probably unnecessary in other abdominal NETs. However, clinicians should use risk factors identified in this study when considering to forego extended VTE prophylaxis in NET patients.

Hepaticojejunostomy for Benign Disease: Long-Term Stricture Rate and Management.

The objective of the study was to determine the long-term stricture rate of hepaticojejunostiomy (HJ) performed for benign disease, to compare stricture rates for transplant patients and nontransplant patients, and to compare the success rates of procedural and surgical treatment options. Hospital charts of 135 consecutive patients undergoing HJ between 1998 and 2016 were analyzed retrospectively. The primary outcome was stricture formation. Secondary outcomes were time to stricture diagnosis and success rates of various interventions. The anastomotic stricture rate was 13.3 per cent (18). The mean follow-up period was 4.3 years. The mean time to stricture diagnosis was 2.3 years. Stricture rates were similar between the transplant (19.2%) and nontransplant, non-Whipple group (13%). Strictures were treated with radiological intervention with a 44.4 per cent success rate; each required multiple interventions. Mortality from liver disease after failure of nonoperative management of HJ strictures reached 30 per cent (3). Five of ten patients who failed radiological intervention underwent HJ revision; the success rate was 80 per cent. Anastomotic strictures of HJ performed for benign disease occur in 13 per cent of patients and typically develop within 2.5 years postoperatively. Yet, given the dangerous sequelae of chronic biliary obstruction and potential delay in presentation, a follow-up is recommended for up to 10 years. When strictures occur, HJ revision should be considered early, after two failed radiological interventions.

Simultaneous hepatic and portal vein ligation induces rapid liver hypertrophy: A study in pigs.

BACKGROUND: Liver hypertrophy induced by partial portal vein occlusion (PVL) is accelerated by adding simultaneous parenchymal transection ("ALPPS procedure"). This preclinical experimental study in pigs tests the hypothesis that simultaneous ligation of portal and hepatic veins of the liver also accelerates regeneration by abrogation of porto-portal collaterals without need for operative transection. METHODS: A pig model of portal vein occlusion was compared with the novel model of simultaneous portal and hepatic vein occlusion, where major hepatic veins draining the portal vein-deprived lobe were identified with intraoperative ultrasonography and ligated using pledgeted transparenchymal sutures. Kinetic growth was compared, and the portal vein system was then studied after 7 days using epoxy casts of the portal circulation. Portal vein flow and portal pressure were measured, and Ki-67 staining was used to evaluate the proliferative response. RESULTS: Pigs were randomly assigned to portal vein occlusion (n = 8) or simultaneous portal and hepatic vein occlusion (n = 6). Simultaneous portal and hepatic vein occlusion was well tolerated and led to mild cytolysis, with no necrosis in the outflow vein-deprived liver sectors. The portal vein-supplied sector increased by 90 ± 22% (mean ± standard deviation) after simultaneous portal and hepatic vein occlusion compared with 29 ± 18% after PVL (P < .001). Collaterals to the deportalized liver developed after 7 days in both procedures but were markedly reduced in simultaneous portal and hepatic vein occlusion. Ki-67 staining at 7 days was comparable. CONCLUSION: This study in pigs found that simultaneous portal and hepatic vein occlusion led to rapid hypertrophy without necrosis of the deportalized liver. The findings suggest that the use of simultaneous portal and hepatic vein occlusion accelerates liver hypertrophy for extended liver resections and should be evaluated further.