Impact of a learning curve model in kidney transplantation on functional outcome and surgical complications in a small volume centre: does size really matter?

Effectiveness of Thermal Barrier Bag for Prolonged Vascular Anastomosis in Kidney Transplantation

BACKGROUND

In kidney transplantation (KT), efforts to minimize rewarming and optimize anastomosis time during vascular anastomosis improve graft outcomes. We recently reported the safety and efficacy of a pouch-type thermal barrier bag (TBB) made of elastomer gel to reduce second-warm ischemic injury during vascular anastomosis. We aimed to examine the usefulness of the TBB in prolonged vascular anastomosis in KT performed by young transplant fellows.

METHODS

Young transplant fellows performed KT under the supervision of certified transplant surgeons. The kidney graft was placed inside the TBB with an outlet for vessels and preserved during vascular anastomosis. A non-contact infrared thermometer measured the graft surface temperature before and after vascular anastomosis. After completion of the anastomosis, the TBB was manually slid out of the transplanted kidney and removed before graft reperfusion. Clinical data, including patient characteristics and perioperative variables, were collected. The primary endpoint was the median graft surface temperature at the end of the anastomosis.

RESULTS

Ten living-donor kidney transplant recipients with a median age of 56.5 years (range, 40-69 years) underwent KT procedures performed by young transplant fellows. The median anastomosis time was 53 (43-67) min. At the end of anastomosis, the median graft surface temperature was 17.7°C (16.3-18.3°C); no serious adverse events or delayed graft function were observed.

CONCLUSION

The TBB can keep transplanted kidneys at a low temperature even with prolonged vascular anastomosis time, thus contributing to the functional preservation of transplanted kidneys and stable transplant outcomes.

The learning curve for open and minimally-invasive kidney transplantation: a systematic review

INTRODUCTION

There is lack of evidence on the impact of surgeons' learning curve on postoperative outcomes after open (OKT) or minimally-invasive (robot-assisted) kidney transplantation (RAKT). The aim of the review was to assess the learning curve (LC) for OKT and RAKT, focusing on intra-, perioperative and functional outcomes.

EVIDENCE ACQUISITION

A systematic review of the English-language literature published between 01/01/2000 - 10/12/2021 was conducted using the MEDLINE (Via PubMed), Web of Science and the Cochrane Library databases according to the principles highlighted by the EAU Guidelines Office and the PRISMA statement recommendations. The review protocol was registered on PROSPERO (CRD42022301132). The overall quality of evidence was assessed according to GRADE recommendations.

EVIDENCE SYNTHESIS

Twelve studies were included in the qualitative analysis. Surgical competence in terms of operative and re-warming times was defined after 30 cases in OKT and after 11-35 cases in RAKT. Decreased complications rates were observed after 20-33 cases in OKT and 10-30 cases in RAKT. Optimal functional outcomes were achieved after 33 cases in OKT and 15-25 cases in RAKT. However, while a poor OKT experience did not influence the LC for RAKT, lack of robotic surgery exposure could lead to a longer LC for the robotic approach.

CONCLUSIONS

OKT and RAKT appear to have similar LCs and might require about 30 cases to achieve optimal surgical and functional outcomes. Previous expertise in OKT is warranted to shorten the LC for RAKT. Further research is needed to validate these thresholds using standardized reporting metrics.

"Time is tissue"-A minireview on the importance of donor nephrectomy, donor hepatectomy, and implantation times in kidney and liver transplantation

Donor organs are exposed to sequential temperature changes during the transplantation process. The role of donor warm ischemia and cold ischemia times on post-transplant outcomes has been extensively studied. Much less attention has been paid to the transient ischemia occurring during donor organ removal and implantation. Recently, it has become clear that prolonged donor nephrectomy and implantation time are independently associated with delayed graft function after kidney transplantation. In addition, implantation time correlates with post-transplant kidney graft function, histology, and survival. Similar detrimental associations of donor hepatectomy and implantation time with early allograft dysfunction, ischemic cholangiopathy, and graft and patient survival after liver transplantation have been demonstrated. This review details kidney and liver temperature changes occurring during procurement and transplantation. It summarizes the effects of the ischemia the kidney and liver sustain during these phases on short- and long-term post-transplant outcomes, advocating the standardized reporting of donor hepatectomy, donor nephrectomy, and implantation times in (inter)national registries. The review also explores strategies to protect the graft from this ischemic injury.

Surgical learning curve in kidney transplantation: A systematic review and meta-analysis

AIM

To assess the impact of the learning curve of kidney transplantation on operative and postoperative complications.

METHODS

A literature search was systematically conducted to evaluate the significance of the learning curve on complications in kidney transplantation. Meta-analyses of the effect of the learning curve on warm ischemic time, total operating time (TOT), vascular and urological complications, postoperative bleeding, lymphocele and infection.

RESULTS

Nine studies met the inclusion criteria and 2762 patients were included in the present meta-analyses. Surgeons at the beginning of the learning curve were found to have longer TOT (mean difference 41.77 (95% CI: 4.48-79.06; P = .03) and more urological complications (risk ratio 3.93; 95% CI: 1.87-8.25; P < .01). No differences were seen in warm ischemic time, postoperative bleeding, lymphocele, and vascular complications.

CONCLUSION

Surgeons at the beginning of their learning curve have a longer TOT and more urological complications, without an effect on postoperative bleeding, lymphocele, infection and vascular complications. For interpretation of the outcomes, the quality and sample size of the evidence should be taken into consideration.

Volume-outcome relationship and minimum volume regulations in the German hospital sector - evidence from nationwide administrative hospital data for the years 2005-2007

BACKGROUND

This paper analyses the volume-outcome relationship and the effects of minimum volume regulations in the German hospital sector.

METHODS

We use a full sample of administrative data from the unselected, complete German hospital population for the years 2005 to 2007. We apply regression methods to analyze the association between volume and hospital quality. We measure hospital quality with a binary variable, which indicates whether the patient has died in hospital. Using simulation techniques we examine the impact of the minimum volume regulations on the accessibility of hospital services.

RESULTS

We find a highly significant negative relationship between case volume and mortality for complex interventions at the pancreas and oesophagus as well as for knee replacement. For liver, kidney and stem cell transplantation as well as for CABG we could not find a strong association between volume and quality. Access to hospital care is only moderately affected by minimum volume regulations.

CONCLUSION

The effectiveness of minimum volume regulations depends on the type of intervention. Depending on the type of intervention, quality gains can be expected at the cost of slightly decreased access to care.

Individual Surgeon Experience Yields Bimodal Effects on Patient Outcomes After Deceased-Donor Liver Transplant: Results of a Quantile Regression for Survival Data

OBJECTIVES

Data on the relevance of surgeon experience in liver transplant procedures are scarce. In this study, we evaluated the effects of individual surgeon experience on survival outcomes after deceased-donor liver transplant.

MATERIALS AND METHODS

In this retrospective analysis of 1193 liver transplant procedures, quantile regression for survival data was performed to assess the effects of surgeon experience. Conditional quantiles of mortality and graft loss were set as primary and secondary outcome measures, respectively, which were categorized as early, midterm, and late.

RESULTS

Greater experience of a surgeon performing hepatectomy increased the risk of early mortality (P = .005) and graft loss (P = .025) when the recipient Model for End-Stage Liver Disease was ≤ 25 and the donor Model for End-Stage Liver Disease was ≤ 1600. In conventional transplant procedures, greater experience of surgeon performing hepatectomy additionally increased the risk of midterm mortality (P = .027) and graft loss (P = .046). Conversely, a graft implant procedure performed by a more experienced surgeon was associated with better early, midterm, and late outcomes after conventional transplants (all P < .037) and reduced the risk of early graft loss when the donor Model for End-Stage Liver Disease score was > 1600 (P = .027).

CONCLUSIONS

Unexpectedly, individual surgeon experience yields bimodal effects on posttransplant outcomes, dependent on the stage of operation, operative technique, severity of recipient status, and transplant risk profile.

Residency in urology and training in kidney transplantation. Results of a national survey

OBJECTIVES

To determine the current state of kidney transplantation (KT) training in a country that is leader in organ donation and transplantation.

MATERIAL AND METHODS

We conducted an online survey by e-mail to 138 urology residents. The survey contained 5 sections: affiliation, training in KT, interest in KT, residents of transplant centers and residents of nontransplant centers.

RESULTS

Sixty-five residents responded, 47.1% of the urologists in training surveyed, representing 28 cities and 15 provinces. Fifty-five percent (n=36) of the respondents deemed the KT training offered during their residency as insufficient, and 85% (n=55) demanded more resources. More than half were not confident in their abilities to perform transplantation surgery over the course of their residency (n=35). Nineteen percent of the residents considered KT an important discipline in their residency, with a mean score of 56.2 (1-100). Among the residents of the transplant centers (69.2%, n=45), 73% (n=33) considered KT when choosing a center for their residency. Of the surveyed residents from nontransplant centers (30.7%, n=20), 45% (n=9) do not perform an external rotation in KT.

CONCLUSIONS

The surveyed residents demand more training in KT. The most common situation is to end a residency without having performed a complete KT. KT is considered an asset when selecting a resident medical intern position and commonly they are part of the transplantation team. The majority of residents are trained in centers with less than 75 transplants/year. External rotations in KT are not the rule in centers where transplantation is not performed.