Adult Living Donor Liver Transplantation Research Articles

Association between neutrophil\u2013lymphocyte ratio change during living donor liver transplantation and graft survival

Preoperative neutrophil–lymphocyte ratio (NLR), has shown a predictive value in living donor liver transplantation (LDLT). However, the change in the NLR during LDLT has not been fully investigated. We aimed to compare graft survival between the NLR increase and decrease during LDLT. From June 1997 to April 2019, we identified 1292 adult LDLT recipients with intraoperative NLR change. The recipients were divided according to NLR change: 103 (8.0%) in the decrease group and 1189 (92.0%) in the increase group. The primary outcome was graft failure in the first year. In addition, variables associated with NLR change during LDLT were evaluated. During 1-year follow-up, graft failure was significantly higher in the decrease group (22.3% vs. 9.1%; hazard ratio 1.87; 95% confidence interval 1.10–3.18; p = 0.02), but postoperative complications did not differ between two groups. This finding was consistent for the overall follow-up. Variables associated with NLR decrease included preoperative NLR > 4, model for end-stage liver disease score, intraoperative inotropic infusion and red blood cell transfusion, and operative duration. The least absolute shrinkage and selection operator model yielded similar results. NLR decrease during LDLT appeared to be independently associated with graft survival. Further studies are needed to confirm our findings.

Portal Vein Complications After Adult Living Donor Liver Transplantation: Time of Onset and Deformity Patterns Affect Long-Term Outcomes.

Portal vein complications (PVCs) after adult living donor liver transplantation (LDLT) are potentially lethal. We categorized PVCs by the time of onset (early versus late, <1month versus ≥1month, respectively) and deformity patterns (portal vein stenosis [PVS], portal vein thrombosis [PVT], and portal vein occlusion [PVO]) to establish optimal treatment strategies. Overall, 35/322 (10.9%) recipients developed PVCs between 2000 and 2019. Pretransplant PVT (odds ratio [OR], 15.20; 95% confidence interval [CI], 3.70-62.40; P<0.001) was the only independent risk factor for PVS. In contrast, male sex (OR, 5.57; 95% CI, 1.71-18.20; P=0.004), pretransplant PVT (OR, 4.79; 95% CI, 1.64-14.00; P=0.004), and splenectomy (OR, 3.24; 95% CI, 1.23-8.57; P=0.018) were independent risk factors for PVT. PVS was successfully treated with interventional radiology regardless of its time of onset. On the other hand, late PVT and PVO had significantly lower treatment success rates (2/15, 13%) compared with those that occurred in the early period (10/11, 91%) despite aggressive intervention (P<0.001). Deformity patterns had a significant impact on the 5-year cumulative incidence of graft loss as a result of PVC (PVO+Yerdel grades 2-4 PVT group [n=16], 41% versus PVS+Yerdel grade 1 PVT group [n=19], 0%; P=0.02). In conclusion, late grades 2 to 4 PVT and PVO are refractory to treatment and associated with poor prognoses, whereas PVS has a good prognosis regardless of time of onset. A tailored approach according to the time of onset and deformity patterns of PVC is essential.

Current status of left lobe adult to adult living donor liver transplantation.

This review describes the history and current state of left lobe living donor liver transplantation (LDLT). The transplant community continues to face an organ shortage on a global scale, and the expansion of LDLT is attractive because it allows us to provide life-saving liver transplants to individuals without drawing from, or depending on, the limited deceased donor pool. Donor safety is paramount in LDLT, and for this reason, left lobe LDLT is particularly attractive because the donor is left with a larger remnant. This article reviews the donor and recipient evaluations for left lobe LDLT, discusses small for size syndrome and the importance of portal inflow modification, and reviews recipient outcomes in right lobe versus left lobe LDLT. Left lobe LDLT was the first adult-to-adult LDLT ever to be performed in Japan in 1993. Since that time, the use of both right and left lobe LDLT has expanded immensely. Recent work in left lobe LDLT has emphasized the need for inflow modification to reduce portal hyperperfusion and early graft dysfunction following transplant. Accumulating evidence suggests, however, that even though early graft dysfunction following LDLT may prolong hospitalization, it does not predict graft or patient survival.

Current status of adult liver transplantation: utilization of living donor versus deceased donor graft.

This article will summarize prior and recent studies comparing outcomes between living donor and deceased donor liver transplantation (LT) in adults and provide a rationale and framework for expanding living donor liver transplantation (LDLT) in Western countries to address the growing critical organ shortage. There is a growing body of evidence demonstrating superior survival outcomes in LDLT in addition to a multitude of other advantages including shorter cold ischemia times, opportunity for pretransplant medical optimization, and expansion of transplant eligibility. Additionally, these outcomes continue to improve with center volume and experience. LDLT in adults emerged in response to an effective donor organ shortage created by the critical discrepancy between donor graft supply and demand. Overcoming this organ shortage and an increasing waitlist mortality requires a liver transplant framework that fully integrates LDLT into liver disease management although continuing to fully maximize deceased donor graft utilization at experience, capable centers. Optimizing both living and deceased donor graft utilization will drastically increase patients' access to LT.

Reply to Comment: A Worldwide Survey of Live Liver Donor Selection Policies at 24 Centers With a Combined Experience of 19 009 Adult Living Donor Liver Transplants.

Reply to Comment: A Worldwide Survey of Live Liver Donor Selection Policies at 24 Centers With a Combined Experience of 19 009 Adult Living Donor Liver Transplants.

Meta-analysis and meta-regression of outcomes for adult living donor liver transplantation versus deceased donor liver transplantation.

Prior single center or registry studies have shown that living donor liver transplantation (LDLT) decreases waitlist mortality and offers superior patient survival over deceased donor liver transplantation (DDLT). The aim of this study was to compare outcomes for adult LDLT and DDLT via systematic review. A meta-analysis was conducted to examine patient survival and graft survival, MELD, waiting time, technical complications, and postoperative infections. Out of 8600 abstracts, 19 international studies comparing adult LDLT and DDLT published between 1/2005 and 12/2017 were included. U.S. outcomes were analyzed using registry data. Overall, 4571 LDLT and 66,826 DDLT patients were examined. LDLT was associated with lower mortality at 1, 3, and 5years posttransplant (5-year HR 0.87 [95% CI 0.81-0.93], p<.0001), similar graft survival, lower MELD at transplant (p<.04), shorter waiting time (p<.0001), and lower risk of rejection (p=.02), with a higher risk of biliary complications (OR 2.14, p<.0001). No differences were observed in rates of hepatic artery thrombosis. In meta-regression analysis, MELD difference was significantly associated with posttransplant survival (R2 0.56, p=.02). In conclusion, LDLT is associated with improved patient survival, less waiting time, and lower MELD at LT, despite posing a higher risk of biliary complications that did not affect survival posttransplant.

Study of Early Postoperative Doppler Changes Post Living Donor Liver Transplantation and Their Impact on Early Mortality and Small-for-Size Syndrome: A Retrospective Study.

BackgroundAdult-to-adult living donor liver transplantation (LDLT) has been a common practice because of the deficiency of deceased donor liver transplants. Liver hemodynamics differ substantially between cases with end-stage liver disease undergoing LT because of various degrees of hepatic affection, nature of implicated causative factors, and pathogenesis of the hepatic disorder. The present retrospective study primarily aimed to study the early postoperative doppler changes after adult to adult LDLT. The secondary aim was to assess these hemodynamics’ impact on early in-hospital deaths and small for size syndrome (SFSS) development.MethodsThis retrospective work was done on 123 adult cases with end-stage liver disease for whom adult LDLT was performed after exclusion of pediatric patients and those with vascular complications.ResultsPostoperative (PO) mean portal vein velocity (PVV), hepatic artery (HA) peak systolic velocity (PSV), and HA resistivity index (RI) declined gradually but significantly post adult LDLT. Phasicity of hepatic veins changes towards the triphasic waveform gradually in the early PO period. There is a notable negative relationship between PO mean PVV with PO mean HA PSV. Higher PO HA RI affected PO mortality, while higher PO PVV and lower HA PSV increased the incidence of SFSS.ConclusionEarly postoperative Doppler changes post-LDLT (PO PVV, HA RI, and HA PSV) can affect both mortality and SFSS development.

EFFECT OF PREOPERATIVE ASSESSMENT ON MINIMIZING LIVING DONOR LIVER TRANSPLANTATION DONOR COMPLICATIONS

Background: In adult Living donor liver transplantation (LDLT), donor safety is of paramount importance, and ideally, there should not be any donor deaths. Objective: To evaluate the potential donor for Living Donor Liver Transplantation as regard general condition, fitness, liver function and segmental anatomy; and assessment of intra- and postoperative complications up to 6 months post-operatively. Patients and methods: The present study conducted on 200 consecutive cases of living donor liver transplantation over a period of 7 years (2012 to 2018). All patients were admitted at the Department of Transplantation, International Medical Center, Armed Forces Egypt. The study was prospective and designed to evaluate the donors preoperatively, criteria of selection, possible intra-operative and postoperative complications. Results: One hundred and thirty two donors (66%) had grade I complications, 60 donors (30%) had grade II complications, 4 (2%) donors had grade IIIa complication, and 123 (6%) donors had grade IIIb complications. Biliary complications were 12% (24 donors) in the form of biliary leak. Conclusion: Right lobe donor hepatectomy can be performed with an acceptably low incidence of complications. LDLT using the right lobe provides adequate hepatic mass for most adult transplant recipients and gives recipient results similar to conventional cadaveric transplantation.

EFFECT OF PREOPERATIVE ASSESSMENT ON MINIMIZING LIVING DONOR LIVER TRANSPLANTATION DONOR COMPLICATIONS

Background: In adult Living donor liver transplantation (LDLT), donor safety is of paramount importance, and ideally, there should not be any donor deaths. Objective: To evaluate the potential donor for Living Donor Liver Transplantation as regard general condition, fitness, liver function and segmental anatomy; and assessment of intra- and postoperative complications up to 6 months post-operatively. Patients and methods: The present study conducted on 200 consecutive cases of living donor liver transplantation over a period of 7 years (2012 to 2018). All patients were admitted at the Department of Transplantation, International Medical Center, Armed Forces Egypt. The study was prospective and designed to evaluate the donors preoperatively, criteria of selection, possible intra-operative and postoperative complications. Results: One hundred and thirty two donors (66%) had grade I complications, 60 donors (30%) had grade II complications, 4 (2%) donors had grade IIIa complication, and 123 (6%) donors had grade IIIb complications. Biliary complications were 12% (24 donors) in the form of biliary leak. Conclusion: Right lobe donor hepatectomy can be performed with an acceptably low incidence of complications. LDLT using the right lobe provides adequate hepatic mass for most adult transplant recipients and gives recipient results similar to conventional cadaveric transplantation.

Technique of Biliary Anastomosis: Targeting the “Achilles´ Heel” of Adult Living Donor Liver Transplant

Biliary complications are regarded as the Achilles´ heel of liver transplantation, especially for living donor liver transplantation (LDLT) due to smaller, multiple ducts and difficult ductal anatomy. In most series, overall biliary complications (biliary leaks and strictures) were reported between 10%-30%.

No diffuse intrahepatic biliary stricture after ABO-incompatible adult living donor liver transplantation using tailored rituximab-based desensitization protocol.

BackgroundRituximab (RTx) desensitization protocol offered good outcome in ABO-incompatible (ABOi) living donor liver transplantation (LDLT). However, diffuse intrahepatic biliary stricture (DIHBS) is still inevitable hurdle. We selectively added postoperative high dose intravenous immunoglobulin (IVIG) and/or simultaneous splenectomy if ABO isoagglutinin titer just before liver transplantation after plasma exchange (PE) was higher than 1/16. Herein, we reported the excellent outcome of ABOi LDLT without DIHBS using tailored desensitization protocol and compared it with that of ABO-compatible (ABOc) LDLT.MethodsSixty-five cases (14.8%) of ABOi LDLTs were performed among 438 primary adult LDLTs in our center between March 2012 and June 2017. We performed 1-to-2 propensity score matching (PSM) to extract 60 cases of ABOi LDLTs and 120 cases of ABOc LDLTs.ResultsThere were no significant differences in clinical characteristics between ABOi and ABOc recipients. There were no significant differences in complications and rejection. There was no DIHBS in both groups. The 1-, 3-, and 5-year overall survival rates were 98.3%, 86.7%, and 82.9% in ABOi group and 96.7%, 86.7%, and 85.4% in ABOc group, respectively (P=0.88). Most common cause of deaths of both groups was hepatocellular recurrence. The 1-, 3-, and 5-year biliary complication (anastomosis leakage or stricture) free survival rates were 81.4%, 69.5%, and 67.5% in ABOi group and 83.0%, 81.3%, and 80.0% in ABOc group, with no significant differences (P=0.11).ConclusionsRTx-based tailored (optional IVIG + splenectomy) desensitization protocol for ABOi LDLT was feasible and acceptable.

Histidine-tryptophan-ketoglutarate solution versus University of Wisconsin solution in adult-to-adult living donor liver transplantation: A propensity score matching analysis from mainland China.

To compare the difference between University of Wisconsin (UW) solution and histidine-tryptophan-ketoglutarate (HTK) solution in adult living donor liver transplantation (LDLT).This study included LDLT patients at the Liver Transplantation Center of West China Hospital of Sichuan University from November 2001 to June 2018. These patients were classified into 2 groups depending on the use of the different preservation solutions, and the confounding factors between the 2 groups were eliminated by propensity score matching. Finally, the incidence of complications; serum examination at postoperative days 1, 3, 5, 7, 14, 21, and 30; and the overall survival rate of the 2 groups were compared to observe whether there were any differences between the 2 preservation solutions.Of the 298 patients we screened, 170 were treated with UW solution and 128 with HTK solution. After propensity score matching, 106 pairs of patients were selected. In the comparison of the 2 groups, the length of intensive care unit stay in the UW group was significantly longer than that in the HTK group (P = .022), but there was no difference in the total length of hospital stay between the 2 groups (P = .277). No statistically significant difference was observed in the 2 groups in terms of the incidence of complications or postoperative examinations. However, the incidence of early allograft dysfunction in the HTK group was slightly lower than that in the UW group (HTK: UW = 14.1%: 20.7%), although the difference was not statistically significant. In terms of the overall survival rate, the 1, 3, and 5-year survival rates of the HTK group were 85.5%, 70.2%, and 65.1%, respectively, while the 1, 3, and 5-year survival rates of the UW group were 83.1%, 67.2%, and 59.8%, respectively, and there was no significant difference between the 2 groups.In conclusion, our study shows that UW solution and HTK solution are equivalent in perioperative safety, the recovery of transplanted liver function, the occurrence of postoperative complications and overall survival and can be safely and effectively applied in adult LDLT. If economic factors are taken into account, HTK can save costs to a certain extent.

RISK FACTORS ASSOCIATED WITH DELISTING OF HEPATOCELLULAR CARCINOMA PATIENT'S CANDIDATES FOR LIVER TRANSPLANTATION

Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide, with morethan 1 million new cases diagnosed every year. Liver transplantation has been used as a curativetreatment for patients with HCC.Liver transplantation offers the best cure chance for unrespectable hepatocellular carcinoma(HCC), but the scarcity of cadaver liver grafts has seriously limited its role. With the recent advancesin adult living donor liver transplantation (LDLT), there is potentially a drastic change inthe role of liver transplantation. Recent Studies have demonstrated the theoretical survival benefitof LDLT over deceased donor liver transplantation (DDLT) which depends largely on thewaiting time and drop‐out rate. This study was conducted to analyze the different risk factorsleading to delisting in liver transplant patients with hepatocellular carcinoma. Fifty patients presentedto Ain Shams Specialized Hospitals from January 2017 to June 2018, with expected averagehepatocellular carcinoma eligible for Adult Living Donor Liver transplantation (ALDLT) werestudied. They were evaluated according to protocol of Ain Shams Center of Organ Transplantation(ASCOT). Inclusion criteria: 1-hepatocellular carcinoma with any underlying cause ofcirrhosis. HCC is first diagnosed using spiral computed tomography of liver and sometimesMagnetic Resonance Imaging (MRI). 2- Patients within University of California San Francisco(UCSF) criteria (one tumor ≤6·5 cm, three nodules with largest ≤4·5cm, & total tumor diameter≤8 cm). 3- Patients within these criteria underwent loco-regional therapy as bridging therapy includingradiofrequency ablation, radio-embolization, trans-arterial chemoembolization, microwaveablation or liver resection to avoid delisting. 4- Patients beyond these criteria underwentloco-regional treatment as means of down staging to be within Milan or UCSF and candidatesfor ALDLT. Exclusion criteria: 1- metastatic HCC patients, 2- macrovascular invasion, & 3-poor general condition for surgery.

RISK FACTORS ASSOCIATED WITH DELISTING OF HEPATOCELLULAR CARCINOMA PATIENT'S CANDIDATES FOR LIVER TRANSPLANTATION

Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide, with morethan 1 million new cases diagnosed every year. Liver transplantation has been used as a curativetreatment for patients with HCC.Liver transplantation offers the best cure chance for unrespectable hepatocellular carcinoma(HCC), but the scarcity of cadaver liver grafts has seriously limited its role. With the recent advancesin adult living donor liver transplantation (LDLT), there is potentially a drastic change inthe role of liver transplantation. Recent Studies have demonstrated the theoretical survival benefitof LDLT over deceased donor liver transplantation (DDLT) which depends largely on thewaiting time and drop‐out rate. This study was conducted to analyze the different risk factorsleading to delisting in liver transplant patients with hepatocellular carcinoma. Fifty patients presentedto Ain Shams Specialized Hospitals from January 2017 to June 2018, with expected averagehepatocellular carcinoma eligible for Adult Living Donor Liver transplantation (ALDLT) werestudied. They were evaluated according to protocol of Ain Shams Center of Organ Transplantation(ASCOT). Inclusion criteria: 1-hepatocellular carcinoma with any underlying cause ofcirrhosis. HCC is first diagnosed using spiral computed tomography of liver and sometimesMagnetic Resonance Imaging (MRI). 2- Patients within University of California San Francisco(UCSF) criteria (one tumor ≤6·5 cm, three nodules with largest ≤4·5cm, & total tumor diameter≤8 cm). 3- Patients within these criteria underwent loco-regional therapy as bridging therapy includingradiofrequency ablation, radio-embolization, trans-arterial chemoembolization, microwaveablation or liver resection to avoid delisting. 4- Patients beyond these criteria underwentloco-regional treatment as means of down staging to be within Milan or UCSF and candidatesfor ALDLT. Exclusion criteria: 1- metastatic HCC patients, 2- macrovascular invasion, & 3-poor general condition for surgery.

Outcomes of living versus deceased donor liver transplantation: initial single center experience from Thailand

Background: The availability of deceased donor in the northern region of Thailand is limited. In 2015, we initiated the adult to adult living donor liver transplantation program. To date, we are the only active adult to adult living donor liver transplantation pro gram in Thailand. We evaluated the short-term outcomes after liver transplantation compare between living and deceased donor liver transplantation. Methods: Retrospective study of adult liver transplantation in our center since 2014. The patients were divided in to a living do nor liver transplantation (LDLT) and deceased donor liver transplantation (DDLT). Baseline characteristic, perioperative data and 1-year survival were compared between two groups. Results: There were 37 cases underwent LT in our hospital since October 2014 (20 DDLT cases and 17 LDLT cases). Baseline characteristics between two groups were not significantly difference. The operative time was longer in LDLT group (P<0.001). However, cold and warm ischemic time were shorter in LDLT group (P<0.001 and P=0.026, respectively). The median ventilator, intensive care unit and hospital stay were similar. The incidence of biliary complication was higher in LDLT group (47% vs 10%, P<0.001). The vascular related complications were not significant difference. Nighty-day and 1-year survival were not significant difference between LDLT and DDLT group (84.6% vs. 84.2% and 76.9% vs. 84.2% respectively, P=0.706). Conclusions: In the region where deceased donor shortage, LDLT showed similar results compare to DDLT in terms of peri-oper ative outcomes and patient survival even done by the beginner LDLT program. However, the incidence of biliary related complica tion was significant higher in LDLT group.

Pure laparoscopic donor right hepatectomy for adult living donor liver transplantation: initial report from Southeast Asia liver transplant center

Pure laparoscopic donor right hepatectomy for adult living donor liver transplantation: initial report from Southeast Asia liver transplant center

Redo hepatic artery reconstruction for thrombosis can save grafts and patients without retransplantation: lessons learned from 1,355 adult living donor liver transplantations

Redo hepatic artery reconstruction for thrombosis can save grafts and patients without retransplantation: lessons learned from 1,355 adult living donor liver transplantations

Study of factors affecting Small for Size Syndrome Post-Adult living donor liver transplantation

Recently, increasing evidence showed that small-for-size syndrome (SFSS) is a multifactorial disease which is precipitated by various perioperative factors other than graft size. We conducted the current work to evaluate perioperative effectors, which can increase the risk of SFSS following adult living-donor liver transplantation (LDLT). This is a retrospective study on 110 adult cirrhotic cases (mean age of 48.4±6.9 years old) who underwent adult LDLT. Most cases were males (89%). Cases were categorized into two groups based on the occurrence of SFSS. The groups were compared regarding preoperative (gender, age, comorbidities, baseline investigations), intraoperative (mean blood pressure and glucose; mean operation time; number of packed red cells, plasma, platelets, and cryoprecipitate units; time of cold and warm ischemia, and anhepatic phase; preclamping and post-reperfusion portal pressures), and postoperative factors (relevant investigations, hospital stay). Postoperatively, 23 patients developed SFSS (20.9%). SFSS group had significantly lower preoperative graft recipient weight ratio (GRWR) (0.76±0.1% versus 1.03±0.15, respectively; p<0.001), and elevated MELD scores (19±2.1 versus 17.9±4; p=0.024). Preclamping and post-reperfusion portal pressures of ≥22.5 and 17.5mmHg, exhibited a sensitivity of 95.7% and 91.3% and specificity of 87.4% and 88.9% respectively, for SFSS prediction. SFSS risk is significantly linked to GRWR, MELD score, and intraoperative portal haemodynamics. Intraoperative portal haemodynamics exhibited good diagnostic accuracy for SFSS prediction and represented promising indicators for the prediction of SFSS.

Predictors of perioperative morbidity and mortality in adult living donor liver transplantations: report of results of a tertiary hospital

BackgroundThe aim of this study was to investigate the risk factors effective in perioperative morbidity and mortality in 161 living donor liver transplantations (LDLT).ResultsThe most common indication for living donor transplantation was cryptogenic cirrhosis. The most common complication was biliary problems in 62.16% cases. Sepsis was the most common cause of in 52%. Patients in whom sepsis was observed, significantly prolonged stay under mechanical ventilation and prolonged ICU stay were detected. In patient group in whom mortality was observed, higher amounts of erythrocytes, fresh frozen plasma (FFP), and platelets were transfused, and patients remained longer under mechanical ventilation treatment, and in the ICU.ConclusionPerioperative morbidity and mortality was found to be significantly related with higher amounts of erythrocytes and FFP transfusions and longer operative and warm ischemia times. Sepsis was found to be the most common cause of mortality.

Robotic Versus Open Right Lobe Donor Hepatectomy for Adult Living Donor Liver Transplantation: A Propensity Score-Matched Analysis.

Robotic right lobe donor hepatectomy (RRLDH) is rarely performed, and data concerning its safety and efficacy are lacking. Here we compare our series of RRLDHs with a similar cohort undergoing open right lobe donor hepatectomy (ORLDH) with a propensity score-matched (PSM) analysis. Among 263 consecutive adult patients undergoing right lobe living donor hepatectomy from January 2015 until July 2019, 35 RRLDHs were matched to 70 ORLDHs. A 1:2 PSM analysis was performed to make the groups comparable for donor sex, age, and body mass index (BMI) and for recipient sex, age, BMI, Model for End-Stage Liver Disease score, and indication for transplant. Operative time was longer in RRLDHs compared with ORLDHs (504±73.5 versus 331±65.1minutes; P<0.001) but significantly decreased with the number of patients (P<0.001). No conversions occurred. First warm ischemia time was longer and blood loss significantly less in RRLDHs (P=0.001 and 0.003, respectively). Overall donor complications were similar: 2 (6%) in RRLDHs versus 12 (17%) in ORLDHs (P=0.13). Biliary leak occurred in 1 (3%) patient receiving a robotic procedure and 2 (3%) patients receiving the conventional approach. Donors undergoing robotic surgery required less patient-controlled analgesia and had a shorter hospital stay compared with the open surgery group (P<0.001 and P=0.001, respectively). No significant differences in graft anatomical data and recipient outcomes were recorded. RRLDH is feasible, safe, and reproducible, with significantly decreased blood loss and a shorter hospital stay compared with the open procedure. The first 35 patients receiving the robotic procedure showed a substantial reduction in operative time, reflecting a rapid shortening of the learning curve.