Effective and safe implementation of robot-assisted donor nephrectomy by experienced laparoscopic surgeons.

BACKGROUND: In June 2021, the first robot-assisted donor nephrectomy (RADN) was performed at the Leiden University Medical Center (LUMC), the Netherlands. The goal of this study was to investigate whether this procedure has been implemented safely and efficiently. METHODS: RADN was retrospectively compared to laparoscopic donor nephrectomy (LDN) performed during the same time period (June 2021 until November 2022). Patients were assigned to RADN depending on the availability of the da Vinci robot and surgical team. The studied endpoints were postoperative complications, operative time, estimated blood loss, warm ischemic time (WIT), and postoperative pain experience. For analysis, the Student's t-test and Chi-squared test were used for, respectively, continuous and categorical data. RESULTS: Forty RADN were compared to 63 LDN. Total insufflation time was significantly longer in RADN compared to LDN (188 min (169-214) versus 172 min (144-194); p = 0.02). Additionally, WIT was also found to be significantly higher in the robot-assisted group (04:54 min vs. 04:07 min; p < 0.01). No statistical differences were found in postoperative outcomes (eGFR of the recipient at 3-month follow-up, RADN 54.08 mL/min ±18.79 vs. LDN 56.41 mL/min ±16.82; p = 0.52), pain experience, and complication rate. CONCLUSION: RADN was safely and efficiently implemented at the LUMC. It's results were not inferior to laparoscopic donor nephrectomy. Operative time and warm ischemic times were longer in RADN. This may relate to a learning curve effect. No clinically relevant effect on postoperative outcomes was observed.

Certification Training and Liver Transplant Experience Improves Liver Procurement Outcomes: The Dutch Approach.

BACKGROUND: This study investigates the impact of certification training and liver transplant experience on procurement outcomes of deceased donor liver procurement in the Netherlands. METHODS: Three groups (trainee, certified, and master) were formed, with further subdivision based on liver transplant experience. Three key outcomes-surgical injury, graft discard after injury, and donor hepatectomy duration-were analyzed. RESULTS: There were no significant differences in surgical graft injury in the three groups (trainee, 16.9%; certified, 14.8%; master, 18.2%; P = 0.357; 2011 to 2018). The only predictor for surgical graft injury was donation after cardiac death (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.10-2.02). Of the three groups, the master group had the highest discard rate after surgical injury (trainee, 0%; certified, 1.3%; master, 2.8%; P = 0.013). Master group without liver transplant experience (OR, 3.16; 95% CI, 1.21-8.27) and male donor sex (OR, 3.58; 95% CI, 1.32-9.73) were independent risk factors for discarding livers after surgical injury. Independent predictors for shorter hepatectomy durations included donors older than 50 years (coefficient [Coeff], -7.04; 95% CI, -8.03 to -3.29; P < 0.001), and master group (Coeff, -9.84; 95% CI, -14.37 to -5.31; P < 0.001) and certified group with liver transplant experience (Coeff, -6.54; 95% CI, -10.83 to -2.26; P = 0.003). On the other hand, master group without liver transplant experience (Coeff, 5.00; 95% CI, 1.03-8.96; P = 0.014) and donation after cardiac death (Coeff, 10.81; 95% CI, 8.32-13.3; P < 0.001) were associated with longer hepatectomy durations. CONCLUSIONS: Training and certification in abdominal organ procurement surgery were associated with a reduced discard rate for surgical injured livers and shorter hepatectomy times. The contrast between master group with and without liver transplant experience underscores the need for specialized training in this field.

Quality assessment of donor liver procurement surgery using an unadjusted CUSUM prediction model. A practical nationwide evaluation.

BACKGROUND: The aim of this study was to analyze the value of the unadjusted CUSUM graph of liver surgical injury and discard rates in organ procurement in the Netherlands. METHODS: Unadjusted CUSUM graphs were plotted for surgical injury (C event) and discard rate (C2 event) from procured livers accepted for transplantation for each local procurement team compared with the total national cohort. The average incidence for each outcome was used as benchmark based on procurement quality forms (Sep 2010-Oct 2018). The data from the five Dutch procuring teams were blind-coded. RESULTS: The C and C2 event rate were 17% and 1.9%, respectively (n = 1265). A total of 12 CUSUM charts were plotted for the national cohort and the five local teams. National CUSUM charts showed an overlapping "alarm signal." This overlapping signal for both C and C2, albeit a different time period, was only found in one local team. The other CUSUM alarm signal went off for two separate local teams, but only for C events or C2 events respectively, and at different points in time. The other remaining CUSUM charts showed no alarm signaling. CONCLUSION: The unadjusted CUSUM chart is a simple and effective monitoring tool in following performance quality of organ procurement for liver transplantation. Both national and local recorded CUSUMs are useful to see the implication of national and local effects on organ procurement injury. Both procurement injury and organ discard are equally important in this analysis and need to be separately CUSUM charted.

Real-life data on the impact of successful downstaging in patients with hepatocellular carcinoma: A Dutch Multicenter Study.

Patients with Barcelona Clinic Liver Cancer intermediate stage hepatocellular carcinoma (HCC) theoretically are an excellent group to consider downstaging using locoregional therapy (LRT) since they do not have extrahepatic spread or vascular invasion. Once successful, this can change the treatment strategy from palliative to curative intention. Although downstaging therapy is suggested in guidelines, it is still not widely accepted. Moreover, studies on downstaging are mainly performed in high-incidence HCC countries. Therefore, our aim was to gain insight in therapeutic strategies in patients with intermediate stage HCC and their impact on intention-to-treat survival in a real-life setting in a low-incidence HCC country. We retrospectively analyzed data from the national Dutch HCC registry. From this database, consisting of 1409 patients with a diagnosis of HCC between 2005-2013 in 5 Dutch tertiary referral centers, we identified 165 patients with intermediate stage HCC. Out of these patients, 63 (38%) were not offered LRT, whereas 102 (62%) did receive LRT. Subsequently, 50 (49%) of the 102 patients who received LRT were successfully downstaged. Eleven patients (22% of successfully downstaged patients) eventually underwent liver transplantation. Cox regression analysis showed that a lower MELD score, an AFP value <100 ng/ml, successful downstaging and liver transplantation (all ≤p = 0.01) were positively associated to overall survival. In conclusion, our results demonstrate that LRT is not routinely offered to intermediate stage HCC patients in the Netherlands. Nevertheless, we showed that patients with intermediate stage HCC who are successfully downstaged have a survival benefit compared to those who were not.

High Position of the Third Renal Transplant and Alternative Urinary Tract Reconstruction in a Complicated Case.

The decision-making process for treatment of patients with end-stage renal failure, multiple failed renal transplants, and severe comorbidities can be exceedingly difficult due to the inapplicability of many common surgery methods. In this article, we report the treatment of such a patient who underwent a third renal transplant and subsequently developed a ureteral stenosis. The third kidney had been transplanted with a high abdominal position and a partially intra- and retroperitoneally placed ureter due to a bilaterally obtained iliac fossa and severe abdominal adhesions. For the severe ureteric stenosis, an alternative urinary tract reconstruction was developed by making use of the native ureter contralateral to the graft by tunneling under the sigmoid. We recommend this surgical method as a valid alternative for patients with severe ureteric graft stenosis, when treatment with stenting and common surgical ureter reconstruction methods are not feasible.

Simultaneous Pancreas-Kidney Transplant After Bricker Loop Urinary Diversion: A Case Report.

Simultaneous pancreas-kidney transplant is the ultimate therapy for patients who have uncontrolled and complicated type 1 diabetes mellitus with end-stage renal disease. The combined pancreas transplant provides a euglycemic milieu for the kidney and protects it from recurrence of diabetic complications. Our patient, a 41-year-old woman with end-stage diabetic nephropathy and history of multiple abdominal surgeries (ovarian cyst fenestration, adnexal extirpation, abdominal wall reconstruction), including urinary diversion (Bricker loop, above double J stent), underwent simultaneous pancreas-kidney transplant. After reperfusion, the kidney had immediate function and creatinine levels dropped to normal levels during the early postoperative period (creatinine of 102 µmol/L, estimated glomerular filtration rate of 52 mL/min/1.73 m2) and remained stable during follow-up. Serum glucose levels dropped to within normal ranges postoperatively and remained so during follow-up. The postoperative course was complicated by hydronephrosis due to transient edema of the anastomosis of the ureter to the Bricker loop, after early incidental removal of the double J catheter. This was successfully treated with a temporary percutaneous nephrostomy. Multiple previous surgeries, including a Bricker deviation, may not be a definitive contraindication for simultaneous pancreas-kidney transplant. In selected cases, special considerations may lead to a successful procedure providing better quality of life and life expectancy, even for patients with multiple comorbidities.

Retrospective study on detection, treatment, and clinical outcome of graft thrombosis following pancreas transplantation.

Complete graft thrombosis is the leading cause of early graft loss following pancreas transplantation. Partial thrombosis is usually subclinical and discovered on routine imaging. Treatment options may vary in such cases. We describe the incidence and relevance of partial graft thrombosis in a large transplant center. All consecutive pancreas transplantation at our center (2004-2015) were included in this study. Radiological follow-up, type and quantity of thrombosis prophylaxis, complications and, graft and patient survival were collected. Partial thrombosis and follow-up were also studied. All 230 pancreas transplantations were included in the analysis. Computed tomography was performed in most cases (89.1%). Early graft failure occurred in 23 patients (13/23 due to graft thrombosis, 3/23 bleeding, 1/23 anastomotic leakage, 6/23 secondary to antibody mediated rejection). There was evidence of partial thrombosis in 59 cases (26%), of which the majority was treated with heparin and a vitamin K antagonist with graft preservation in 57/59 patients (97%). Thrombosis is the leading cause of early graft loss following pancreas transplantation. Computed tomography allows for early detection of partial thrombosis, which is usually subclinical. Partial graft thrombosis occurs in about 25% of all cases. In this series, treatment with anticoagulant therapy (heparin and vitamin K antagonist) resulted in graft preservation in almost all cases.

Excessively Long Duodenum of the Pancreatic Graft Segment as a Rare Cause of Hyperammonemia After Simultaneous Pancreas-Kidney Transplant.

Simultaneous pancreas-kidney transplant is currently standard therapy to achieve long-term insulin-free euglycemia in patients with type 1 diabetes mellitus and concomitant end-stage kidney failure. A patient with symptoms of encephalopathy caused by hyperammonemia and with new-onset iron deficiency anemia was admitted to our institution 20 months after a simultaneous pancreas-kidney transplant. Detailed screening did not reveal any specific cause for the hyperammonemia, and despite standard treatment, hyperammonemia did not resolve. An abdominal computed tomographic scan was performed, which showed a distended duodenal segment of the pancreas graft. This was confirmed during exploratory laparotomy when the anastomosis between duodenum and ileum was dismantled and found not to be stenotic. The excessively long stumps of the duodenum were then dissected and shortened, and a new anastomosis between graft-duodenum and recipient-ileum was created. The operation was followed by an uncomplicated postoperative course in which the serum ammonia normalized on the first postoperative day and remained normal afterwards. An excessively long segment of the duodenum of the pancreatic graft may lead to encephalopathy with hyperammonemia after a simultaneous pancreas-kidney transplant. This emphasizes the need for meticulous preparation of the graft to avoid this complication.

Professionalization of surgical abdominal organ recovery leading to an increase in pancreatic allografts accepted for transplantation in the Netherlands: a serial analysis.

Professional abdominal organ recovery with certification has been mandatory in the Netherlands since 2010. This study analyses the effects of certification (January 2010-September 2015) on pancreas transplantation and compares it to an era before certification (February 2002-May 2008) for surgical injuries and the number of pancreases transplanted. A total of 264 cases were analysed. Eighty-four recovered pancreases (31.8%) with surgically injuries were encountered. Forty-six of those were surgically salvaged for transplantation, resulting in a total of 226 (85.6%) being transplanted. It was found that certified surgeons recovered grafts from older donors (36.8 vs. 33.3; P = 0.021), more often from donation after circulatory death (DCD) donors (18% vs. 0%; P < 0.001) and had less surgical injuries (21.6% vs. 41.0%; P < 0.001). Certification (OR: 0.285; P < 0.001) and surgeons from a pancreas transplant centre (OR: 0.420; P = 0.002) were independent risk factors for surgical organ injury. Predictors for proceeding to the actual pancreas transplantation were a recovering surgeon from a pancreas transplantation centre (OR: 3.230; P = 0.003), certification (OR: 3.750; P = 0.004), donation after brain death (DBD) (OR: 8.313; P = 0.002) and donor body mass index (BMI) (OR: 0.851; P = 0.023). It is concluded that certification in abdominal organ recovery will limit the number of surgical injuries in pancreas grafts which will translate in more pancreases available for transplantation.

MMP-2 is a disease-modifying gene in primary sclerosing cholangitis.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the bile ducts, frequently necessitating orthotopic liver transplantation (OLT), often accompanied by inflammatory bowel disease (IBD). Matrix metalloproteinases (MMPs) are associated with fibrotic diseases caused by the involvement in tissue remodelling. AIM: To evaluate the contribution of MMP-2 and -9 promoter polymorphisms to disease severity in PSC, as assessed by death or need for OLT. METHODS: Matrix metalloproteinase-2 (-1306 C/T) and -9 (-1562 C/T) gene promoter polymorphisms were analyzed in 132 PSC patients. Follow-up was from onset PSC until death, OLT or end of follow-up. RESULTS: Twenty-year cumulative incidence (CI) of death or OLT for PSC patients with MMP-2 CT genotype was 86.5% compared to 52.8% for CC genotype (P = 0.030) and reached 100% at 11.3 years for TT genotype. In patients with IBD, CIs were similar: 20-years CI of death or OLT for MMP-2 CT genotype was 86.0% compared to 49.0% for CC genotype and 100% at 11.3 years for TT genotype. Patients without IBD showed a similar trend in 20 years CI for MMP-2 CT (77.8%) compared to CC (57.8%) and CI for TT genotype reached 100% at 9.3 years. Multivariate analysis showed, along with age at diagnosis, a stepwise increase in hazard ratio for MMP-2 T-allele polymorphism for death or OLT. MMP-9 genotype was not associated with disease severity in PSC. CONCLUSION: Matrix metalloproteinase-2 C to T-1306 gene promoter polymorphism in PSC is an independent risk factor for disease severity as reflected by the need for OLT or disease progression leading to mortality.

Limited sampling model for advanced mycophenolic acid therapeutic drug monitoring after liver transplantation.

BACKGROUND: The immunosuppressive drug mycophenolate mofetil (MMF), with mycophenolic acid (MPA) as active metabolite, is a nonnephrotoxic alternative to calcineurin inhibitors. Therapeutic drug monitoring (TDM) of MPA may improve clinical benefit from MMF therapy, especially in MMF monotherapy or with reduced dose of a calcineurin inhibitor. Limited data are available on TDM strategies for MPA in orthotopic liver transplantation (OLT). The authors here describe the pharmacokinetic (PK) behavior of MPA after OLT and developed a Bayesian limited sampling model for monitoring MMF after OLT. METHODS: PK data were obtained from 57 stable patients, and trapezoidal area under the curve (AUC(0-12h)) was calculated. The effect of the covariates kidney function and serum albumin concentration was studied. A TDM strategy was developed based on individualized population PKs using Bayesian estimations and limited sampling models to predict the MPA AUC. RESULTS: A relationship between MMF dose and MPA AUC was found and a 8-fold apparent clearance range of MPA was observed at the same dose level. Significant relationships of albumin concentration and creatinine clearance with MPA plasma clearance were identified (respectively, r² = 0.12 and 0.24; P < 0.05). A model with limited sampling at 0, 0.5, 1, 2, and 3 hours after drug administration showed very good correlation with trapezoidal AUC(0-12h) with acceptable bias and precision (r² = 0.92, mean prediction error = 1, mean absolute prediction error = 13; P < 0.05). CONCLUSIONS: Remarkable variability of MPA clearance in stable OLT patients exists, which can be partially explained by the patients' albumin serum levels and creatinine clearance. Systemic exposure in these patients can be accurately assessed by the Bayesian limited sampling TDM strategy.

Experimental and theoretical studies of Diels-Alder reaction between methyl (Z)-2-nitro-3-(4-nitrophenyl)-2-propenoate and cyclopentadiene.

ABSTRACT: The Diels-Alder reaction between methyl (Z)-2-nitro-3-(4-nitrophenyl)-2-propenoate and cyclopentadiene yields a mixture of carbodiene Diels-Alder adducts. B3LYP/6-31G(d) simulations indicate that the conversion of addends into methyl (1R*,2S*,3S*,4R*)-2-nitro-3-(4-nitrophenyl)-bicyclo[2.2.1]hept-5-ene-2-carboxylate occurs via two-stage heterodiene Diels-Alder reaction and (in a second step) skeleton rearrangement of the primary cycloadduct, whereas the reaction leading to methyl (1R*,2R*,3R*,4R*)-2-nitro-3-(4-nitrophenyl)-bicyclo[2.2.1]hept-5-ene-2-carboxylate is a single-step process.

Decision making around living and deceased donor kidney transplantation: a qualitative study exploring the importance of expected relationship changes.

BACKGROUND: Limited data exist on the impact of living kidney donation on the donor-recipient relationship. Purpose of this study was to explore motivations to donate or accept a (living donor) kidney, whether expected relationship changes influence decision making and whether relationship changes are actually experienced. METHODS: We conducted 6 focus groups in 47 of 114 invited individuals (41%), asking retrospectively about motivations and decision making around transplantation. We used qualitative and quantitative methods to analyze the focus group transcripts. RESULTS: Most deceased donor kidney recipients had a potential living donor available which they refused or did not want. They mostly waited for a deceased donor because of concern for the donor's health (75%). They more often expected negative relationship changes than living donor kidney recipients (75% vs. 27%, p = 0.01) who also expected positive changes. Living donor kidney recipients mostly accepted the kidney to improve their own quality of life (47%). Donors mostly donated a kidney because transplantation would make the recipient less dependent (25%). After transplantation both positive and negative relationship changes are experienced. CONCLUSION: Expected relationship changes and concerns about the donor's health lead some kidney patients to wait for a deceased donor, despite having a potential living donor available. Further research is needed to assess whether this concerns a selected group.

Reduced quality of life in living kidney donors: association with fatigue, societal participation and pre-donation variables.

Health related quality of life (HRQoL) of living kidney donors on average is good, but some donors experience a low HRQoL after donation. This study assessed the prevalence of reduced HRQoL and explored associations with pre- and post-donation variables. 316 donors (response rate 74%) who donated a kidney between 1997 and 2009 filled in a questionnaire. HRQoL was measured using the Short-Form 36; fatigue using the Multidimensional Fatigue Inventory; societal participation using the Utrecht Scale for Evaluation of Rehabilitation-Participation. Donors on average had better HRQoL than the general population. However, 12% had a reduced physical (PCS) and 18% a reduced mental (MCS) HRQoL. Donors with reduced HRQoL reported greater fatigue (P < 0.01), lower societal participation (P < 0.01) and showed a trend towards statistical significance in experiencing more donor-recipient relationship changes (P = 0.07). Prior to donation, donors with reduced PCS had a higher BMI (P < 0.05) and more often smoked (P < 0.05). Donors with reduced MCS had higher expectations (P < 0.05). Reduced HRQoL is associated with higher BMI, smoking and higher expectations prior to donation. These results may be used to develop a screening instrument to select donors at high risk for reduced HRQoL.

Ultrahigh frequency voltammetry: effect of electrode material and frequency of alternating potential modulation on mass transport at hot-disk microelectrodes.

Ultrahigh frequency voltammetry involves low scan rate voltammetric measurements with microelectrodes polarized by high-frequency large-amplitude alternating potential. The method provides a simple means for studying electrothermal and dielectrophoretic effects, which are important in micro and nanofluidic systems. The method also allows for indirect measurements of electrode impedance at gigahertz frequencies. This increases the upper frequency limit in impedance measurements about 1000 times. In this work we demonstrated, for the first time, that the effect of dielectric relaxation of water can be observed in a simple voltammetric experiment. The paper focuses on the description of electrothermal convection at ac heated disk microelectrodes as a function of frequency and provides a comparison of numerical simulations with experimental results.

Contribution of donor and recipient characteristics to short- and long-term pancreas graft survival.

BACKGROUND: Many donor and recipient factors are known to affect pancreas graft survival. However, their relative importance in explaining differences in graft survival is unknown. Purpose of this study was to retrospectively evaluate the impact of donor and recipient factors on pancreas graft survival, and compare their contribution in explaining graft survival differences. MATERIAL/METHODS: Patient records of all 170 pancreas transplantations (158 Simultaneous Pancreas-Kidney; 12 Pancreas-after-kidney) in the period 1997-2008 were reviewed retrospectively to assess recipient factors before/during transplantation, and to assess graft survival. Eurotransplant reports were reviewed to assess donor factors. RESULTS: Death-censored 1-year graft survival was 88.4% and 82.3% at 3 years. Several factors significantly influenced graft survival: female recipient gender (Hazard Ratio (HR) 2.81[1.10-7.14]), enteric graft drainage (HR 2.85[1.15-7.05]), and donor-recipient match on BMI (HR 2.46[1.01-6.02]). None of the donor factors significantly affected survival. Similar results were found for 1-year survival, except for enteric graft drainage and donor-recipient BMI matching. In total, donor factors explained 3.6% and recipient factors 10.0% of the variance in graft survival. Donor factors were more important for 1-year survival (3.1%), but still less important than recipient factors which explained 6.4%. CONCLUSIONS: Recipient factors are more important in explaining differences in pancreas graft survival than donor factors.

Kinetics of the [4+2] cycloaddition of cyclopentadiene with (E)-2-aryl-1-cyano-1-nitroethenes.

ABSTRACT: The electrophilicity of (E)-2-aryl-1-cyano-1-nitroethenes is not sufficient to induce a zwitterionic course of their [4+2] cycloaddition to cyclopentadiene. The one-step mechanism of these reactions is indicated by the activation parameters, and the substituent and solvent effects on the reaction.