Deleterious Influence of Prolonged Warm Ischemia in Living Donor Kidney Transplantation

A Novel Cooling Device for Kidney Transplant Surgery

Background: Prolonged warm ischemia time (WIT) in kidney transplantation is associated with numerous adverse outcomes including delayed graft function and decreased patient and graft survival. Circumventing WIT lies in maintaining renal hypothermia and efficiently performing the vascular anastomosis during this portion of the procedure. Although numerous methods of intra-operative renal cooling have been proposed, most suffer from practical limitations, and none have been widely adopted. Herein we describe a novel device specifically designed to maintain renal hypothermia during kidney transplant surgery.Methods: Aluminum tubing was organized in a serpentine pattern to create a malleable, form-fitting cooling jacket to manipulate renal allografts during transplant surgery. Adult porcine kidneys were used to test the device with 4°C saline as coolant. Kidneys were placed at 24°C; surface and core temperatures were monitored using implanted thermocouples. Anastomosis of porcine kidney vessels to GORE-TEX® vascular grafts in an ex-vivo operative field was performed to assess the functionality of the device.Results: The device maintained surface and core graft temperatures of ≤5°C after 60 minutes of WIT. Furthermore, the device provided hands-free retraction and support for the allograft. We found that ex-vivo anastomosis testing was enhanced by the presence of the cooling jacket.Conclusions: This proof-of-concept study demonstrated that our novel device is a practical tool for renal transplantation and can maintain sufficiently cool graft temperatures to mitigate WIT in an ex-vivo setting. This device is the first of its kind and has the potential to improve kidney transplant outcomes by eliminating WIT during graft implantation.

Continuous renal surface cooling technique (CSCT) in robotic-assisted kidney transplantation: technique and outcomes from a high-volume center: a prospective cohort study

BACKGROUND

Robot-assisted kidney transplantation (RAKT) surgery is an advanced minimally invasive technique, albeit with extended surgical and kidney ischemia time. To safeguard kidney function, the authors have devised a continuous surface cooling method (CSCT) for intraoperative kidney cooling.

MATERIALS AND METHODS

Patients receiving RAKT were divided into CSCT group and conventional group. The CSCT is a custom-designed apparatus composed of a single-layer plastic bag, featuring an inflow and an outflow that create a closed circuit for the continuous flow of cooling saline. The conventional group utilized ice slush for kidney graft cooling (Vattikuti Urology Institute-Medanta Technique, VUIMT). Patients who underwent open renal transplantation during the same period were also included in the study. All patients were subject to a minimum 2-month follow-up. And 1:3 propensity score matching was used to minimize selection bias.

RESULTS

A total of 144 patients underwent CSCT, 47 underwent VUIMT, and 196 underwent open surgery were included in the study, while after matching, 129, 43, 129 patients were included in the three groups, respectively. The median follow-up time was 19 months. None of the patients experienced delayed graft function, patient mortality, or graft loss. After introducing the kidney into the abdominal cavity for 20 minutes, the surface temperature of the kidney in the CSCT group was notably lower compared to the VUIMT group (15.42±0.88 vs. 21.74±2.53°C, P =0.001). This temperature disparity became more pronounced at 65 min (19.74±1.61 vs. 29.82±1.63°C, P <0.001). At both 3 and 7 days post-transplantation, creatinine levels in the VUIMT group were significantly higher than those in the CSCT and open surgery groups (at 3 days, 244.13±45.61 vs. 182.51±55.47 in CSCT group, P <0.001, or vs. 182.77±61.32 in the open surgery group, P <0.001; at 7 days, 162.42±54.86 vs. 143.11±44.32 in the CSCT group, P <0.001, or vs. 135.23±45.27 in the open surgery group, P <0.001). No differences were observed in blood creatinine, estimated glomerular filtration rate, and perioperative complications between the CSCT and open surgery groups.

CONCLUSION

The CSCT presents a significant advantage over the traditional VUIMT method in terms of kidney cooling and early postoperative kidney function preservation. Additional research is required to ascertain whether the CSCT can enhance the long-term prognosis of kidney transplant recipients.

Safety and graft outcome of right retroperitoneal laparoscopic donor nephrectomy for living donor kidney transplantation: A comparison with left retroperitoneal laparoscopic donor nephrectomy

INTRODUCTION

The left kidney is often preferred for living donor kidney transplantation because of its anatomical advantages. However, the right kidney may be procured due to donor conditions. Few studies have assessed the safety and graft outcome of right retroperitoneal laparoscopic donor nephrectomy (RDN). This study aimed to compare the outcomes between right and left RDN with respect to donor outcome and the graft function of recipients.

METHODS

This retrospective study included 230 consecutive living donor kidney transplants performed at our institution between May 2019 and March 2023. We reviewed the outcomes of kidney transplant in the right and left kidneys after RDN.

RESULTS

A total of 230 living donor kidney transplants were performed, with 32 donors receiving right RDN (right RDN group) and 198 donors receiving left RDN (left RDN group). The renal veins and ureters were significantly shorter in the right RDN group than in the left RDN group (both p < .001). Donor operation and warm ischemia time were significantly longer in the right RDN group than in the left RDN group (p = .012 and p < .001, respectively). None of the groups exhibited any cases of delayed graft function owing to donor-related reasons. Perioperative changes in the estimated glomerular filtration rate of recipients and death-censored graft survival were not significantly different between the two groups.

CONCLUSIONS

In RDN, the outcomes of right donor nephrectomy were comparable to those of left donor nephrectomy in terms of donor safety and recipient renal function.

Retrospective analysis of the perioperative outcome in living donor kidney transplantation with multiple renal arteries: does accessory vessel ligation affect the outcome?

PURPOSE

Accurate surgical reconstruction of arterial vascular supply is a crucial part of living kidney transplantation (LDKT). The presence of multiple renal arteries (MRA) in grafts can be challenging. In the present study, we investigated the impact of ligation versus anastomosis of small accessory graft arteries on the perioperative outcome.

METHODS

Clinical and radiological outcomes of 51 patients with MRA out of a total of 308 patients who underwent LDKT with MRA between 2011 and 2020 were stratified in two groups and analyzed. In group 1 (20 patients), ligation of accessory arteries (ARAs) and group 2 (31 patients) anastomosis of ARAs was performed.

RESULTS

Significant differences were observed in the anastomosis-, surgery-, and warm ischemia time (WIT) in favor of group 1. Students t-test showed comparable serum creatinine levels of 2.33 (± 1.75) to 1.68 (± 0.83) mg/dL in group 1 and 2.63 (± 2.47) to 1.50 (± 0.41) mg/dL in group 2, were seen from 1 week to 1 year after transplant. No increased rates of Delayed graft function (DGF), primary transplant dysfunction and transplant rejection were seen, but graft loss and revision rates were slightly higher when the ARAs were ligated. Analysis of Doppler sonography revealed that segmental perfusion deficits tend to regenerate during the clinical course.

CONCLUSION

Ligation of smaller accessory renal arteries may not affect the outcome of living kidney transplantation, except for a minor increase in the reoperation rate. Segmental perfusion deficits of the graft seem to regenerate in most cases as seen in Doppler sonography.

A comparison of pre- and post-operative outcomes in living donors undergoing transperitoneal laparoscopic nephrectomy and open nephrectomy: a retrospective single-center study

BACKGROUND

Kidney transplantation is often regarded as the preferred therapy for end-stage renal disease. Several surgical procedures have been developed to reduce postoperative donor complications, while maintaining kidney quality.

OBJECTIVE

This study aimed to compare the preoperative and postoperative outcomes of living kidney donors who underwent either transperitoneal laparoscopic nephrectomy or open nephrectomy.

DESIGN AND SETTING

Retrospective study conducted in Istanbul, Turkey.

METHODS

Fifty-five living-related kidney donors underwent nephrectomy and were retrospectively divided into two groups: 21 donors who underwent open nephrectomy (Group 1) and 34 donors who underwent transperitoneal laparoscopic nephrectomy (Group 2).

RESULTS

In comparison to the donors who underwent open nephrectomy, those who underwent transperitoneal laparoscopic nephrectomy had significantly shorter postoperative hospital stays (2.3 ± 0.2 versus 3.8 ± 0.8 days, P = 0.003), duration of urinary catheterization (1.2 ± 0.8 days versus 2.0 ± 0.7 days, P = 0.0001), operating times (210 ± 27 minutes versus 185 ± 24 minutes, P = 0.02), and less blood loss (86 ml versus 142 ml, P = 0.048). There was no statistically significant difference between the two groups with regard to the estimated blood transfusion and warm ischemia time. The preoperative week, first postoperative week, and 1-month postoperative serum creatinine levels were comparable between the groups.

CONCLUSIONS

Laparoscopic donor nephrectomy can be safely performed at centers with expertise in laparoscopic surgery. Laparoscopic donor nephrectomy has better outcomes than open donor nephrectomy in terms of length of hospital stay, duration of urinary catheterization, operating time, and blood loss.

The Impact of Combined Warm and Cold Ischemia Time on Post-transplant Outcomes

Background

Prolonged warm ischemia time (WIT) and cold ischemia time (CIT) are independently associated with post-transplant graft failure; their combined impact has not been previously studied. We explored the effect of combined WIT/CIT on all-cause graft failure following kidney transplantation.

Methods

The Scientific Registry of Transplant Recipients was used to identify kidney transplant recipients from January 2000 to March 2015 (after which WIT was no longer separately reported), and patients were followed until September 2017. A combined WIT/CIT variable (excluding extreme values) was separately derived for live and deceased donor recipients using cubic splines; for live donor recipients, the reference group was WIT 10 to <23 minutes and CIT >0 to <0.42 hours, and for deceased donor recipients the WIT was 10 to <25 minutes and CIT 1 to <7.75 hours. The adjusted association between combined WIT/CIT and all-cause graft failure (including death) was analyzed using Cox regression. Secondary outcomes included delayed graft function (DGF).

Results

A total of 137 125 recipients were included. For live donor recipients, patients with prolonged WIT/CIT (60 to ≤120 minutes/3.04 to ≤24 hours) had the highest adjusted hazard ratio (HR) for graft failure (HR = 1.61, 95% confidence interval [CI] = 1.14-2.29 relative to the reference group). For deceased donor recipients, a WIT/CIT of 63 to ≤120 minutes/28 to ≤48 hours was associated with an adjusted HR of 1.35 (95% CI = 1.16-1.58). Prolonged WIT/CIT was also associated with DGF for both groups although the impact was more driven by CIT.

Conclusions

Combined WIT/CIT is associated with graft loss following transplantation. Acknowledging that these are separate variables with different determinants, we emphasize the importance of capturing WIT and CIT independently. Furthermore, efforts to reduce WIT and CIT should be prioritized.

Mean Warm Ischemia Time among Kidney Transplant Patients in a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

In renal transplantation, warm ischemia time is the interval from the removal of a procured kidney from ice storage to initiating graft reperfusion. Successful kidney transplantation depends on warm ischemia time. The study aims to find the mean warm ischemia time among kidney transplant patients in a tertiary care centre.

Methods

This descriptive cross-sectional study was conducted among kidney transplant patients in a tertiary care centre. Data from 15 December 2012 to 15 October 2022 were collected between 1 December 2022 to 4 January 2023 from the hospital records. Ethical approval was taken from the Nepal Health Research Council (Reference number: 1341). All first-time living-related kidney transplant recipients were included in the study. All the patients undergoing kidney transplants from brain-dead donors were excluded from the study. Convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated.

Results

Among 230 patients, the mean warm ischemia time was 35.45±7.35 min. The mean first warm ischemia time was 4.28±2.05 min and the mean second warm ischemia time was 31.27±7.04 min. The mean age of the recipients was 35.14±10.49 years (range 14-64), of which 173 (75.20%) were male and 57 (24.80%) were female.

Conclusions

The mean warm ischemia time among kidney transplant patients in a tertiary care centre was similar to the studies done in similar settings.

Keywords

kidney transplantation; prevalence; warm ischemia.

Systematic review of techniques and devices used to avoid warm ischemia time injury during kidney transplantation

PURPOSE

The lack of a reliable and reproducible technique to ensure a constantly low temperature of the graft during kidney transplantation (KT) may be a cause of renal nonfunction. The aim of this review was to assess all the methods and devices available to ensure hypothermia during vascular anastomosis in KT.

METHODS

A literature search was conducted through May 2022 using PubMed/Medline, Cochrane Library, Embase and Web of Science databases. Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were followed to identify eligible studies. The review protocol was registered on PROSPERO (CRD42022326550).

RESULTS

A total of 20 studies reporting on four hypothermia techniques met our inclusion criteria. Simple instillation of cold serum is not sufficient, the graft reaching up to 33 ℃ at the end of warm ischemia time (WIT). Plastic bags filled with ice slush have questionable efficiency. The use of a gauze jacket filled with ice-slush was reported in 12/20 studies. It ensures a graft temperature up to 20.3 ℃ at the end of WIT. Some concerns have been linked to potentially inhomogeneous parenchymal cooling and secondary ileus. Novel devices with continuous flow of ice-cold solution around the graft might overcome these limitations, showing a renal temperature below 20 ℃ at all times during KT.

CONCLUSION

The gauze filled with ice slush is the most common technique, but several aspects can be improved. Novel devices in the form of cold-ischemia jackets can ensure a lower and more stable temperature of the graft during KT, leading to higher efficiency and reproducibility.

Renal Vessel Extension With Cryopreserved Vascular Grafts: Overcoming Surgical Pitfalls in Living Donor Kidney Transplant

In LDKT, right kidneys and kidneys with anomalous vascularization are often deferred because of concerns on complications and vascular reconstructions. To date, only few reports have examined renal vessel extension with cryopreserved vascular grafts in LDKT. The aim of this study is to investigate the effect of renal vessel extension on short-term outcomes and ischemia times in LDKT. From 2012 to 2020, recipients of LDKT with renal vessels extension were compared with standard LDKT recipients. Subset analysis of rights grafts and grafts with anomalous vascularization, with or without renal vessel extension, was performed. Recipients of LDKT with (n = 54) and without (n = 91) vascular extension experienced similar hospital stays, surgical complications and DGF rates. For grafts with multiple vessels, renal vessel extension granted a faster implantation time (44±5 vs. 72±14 min), which resulted comparable to that of standard anatomy grafts. Right kidney grafts with vascular extension had a faster implantation time compared to right kidney grafts without vascular lengthening (43±5 vs. 58±9 min), and a comparable implantation time to left kidney grafts. Renal vessel extension with cryopreserved vascular grafts allows faster implantation time in right kidney grafts or grafts with anomalous vascularization, maintaining similar surgical and functional outcomes.

Renal transplant anastomotic time-Every minute counts!

The impact of anastomotic time in renal transplant is under recognized and not well studied. It is one of the few controllable factors that affect the incidence of delayed graft function (DGF). Our study aimed at quantifying the impact of anastomotic time. We performed a retrospective review of 424 renal transplants between the years 2006 and 2020. A total of 247 deceased donor renal transplants formed the study cohort. Patients were divided into two groups based on the presence or absence of DGF. Variables with p < 0.3 were analyzed using the binary logistic regression test. The final analysis showed anastomotic time to be significantly associated with DGF with odds ratio of 1.04 per minute corresponding to 4% increase in DGF incidence with every minute increment in anastomotic time. Other variables that had significant impact on DGF were DCD donor (odds ratio - 8.7) and donor terminal creatinine. We concluded that anastomotic time had significant impact on the development of DGF and hence should be minimized.

Technical skills simulation in transplant surgery: a systematic review

Purpose

 Transplant surgery is a demanding field in which the technical skills of the surgeon correlates with patient outcomes. As such, there is potential for simulation-based training to play an important role in technical skill acquisition. This study provides a systematic assessment of the current literature regarding the use of simulation to improve surgeon technical skills in transplantation.

Methods

 Data were collected by performing an electronic search of the PubMed and Scopus database for articles describing simulation in transplant surgery. The abstracts were screened using the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. Three reviewers analyzed 172 abstracts and agreed upon articles that met the inclusion criteria for the systematic review.

Results

 Simulators can be categorized into virtual reality simulators, cadaveric models, animal models (animate or inanimate) and synthetic physical models. No virtual reality simulators in transplant surgery are described in the literature. Three cadaveric models, seven animal models and eight synthetic physical models specific to transplant surgery are described. A total of 18 publications focusing on technical skills simulation in kidney, liver, lung, pancreas, and cardiac transplantation were found with the majority focusing on kidney transplantation.

Conclusions

 This systematic review identifies currently reported simulation models in transplant surgery. This will serve as a reference for general surgery and transplant surgery professionals interested in using simulation to enhance their technical skills.

The effect of single or multiple arteries in the donor kidney on renal transplant surgical outcomes

BACKGROUND

As the number of end-stage renal disease (ESRD) patients is increasing, but there are not enough living donors, it is necessary to broaden the criteria for candidates who can undergo donor nephrectomy. Thanks to surgeons' increasing experience with laparoscopic donor nephrectomy (LND), multiple renal artery grafts, previously considered a relative contraindication to donor nephrectomy, have become candidates for LDN. We aimed to compare the outcomes of donors and recipients with single artery and with multiple arteries in LDN.

METHODS

A total of 214 patients were included in the study. Patients were divided into two groups according to the number of donor arteries: donors with one artery (group 1) and donors with multiple arteries (group 2). The number of donor arteries, operative time, warm ischemia time (WIT), cold ischemia time (CIT), arterial anastomosis time, venous anastomosis time, the extent of bleeding, and preoperative complications were recorded to evaluate the preoperative data.

RESULTS

The mean operation time in group 1 was 90.3 ± 11.8 min, while in group 2, it was 102.1 ± 5.5 min (p = 0.000). WIT group 1 was 90.9 ± 4.3 s and group 2 100.6 ± 2.1 s (p = 0.000). Arterial anastomosis time was 12.25 ± 3.8 in group 1 and 22.5 ± 4.5 in group 2 (p = 0.000). No statistically significant difference was found between the two groups in other parameters.

CONLUSION

Increasing the number of donor arteries in renal transplantation (RT) operations prolonged the operation time on both the donor and recipient sides. Still, it had no negative impact on complications or graft function in the postoperative period.

Building a Low-Cost and Low-Fidelity Kidney Transplant Model: A Technical Report on the San Antonio Kidney Transplant Model

One of the most challenging aspects of the kidney transplant operation is performing vascular anastomoses in the confines and depths of the iliac fossa. General surgery residents need to be adequately trained in this skill to maximize their intraoperative experience during their transplant surgery rotation. While several kidney transplant models have been developed, they are limited in their ability to simulate the challenges of performing anastomoses at varying depths and in confined spaces. Furthermore, they may be expensive or require specialized equipment, such as three-dimensional printers, to build. In this technical report, we describe how to build a low-fidelity, low-cost, and portable kidney transplant model capable of simulating vascular anastomoses at varying depths. Our model can be easily replicated for less than 30 USD using materials available in local stores. It uses inexpensive and reusable parts, allowing trainees a high volume of repetitions.

Creating a Single Inflow Orifice From Living Donor Kidney Allografts With Multiple Renal Arteries

Background: Multiple renal arteries (MRA) are often encountered during living-donor kidney transplantation (LDKT), requiring surgeons to pursue complex renovascular reconstructions prior to graft implantation. With improvements in reconstruction and anastomosis techniques, allografts with MRA can be successfully transplanted with similar outcomes to allografts with a single renal artery. Here, we describe in detail various surgical techniques for reconstruction of MRA grafts with the intent of creating a single arterial inflow.

Methods: We retrospectively reviewed the medical records of all LDKT recipients with laparoscopically procured MRA kidneys between March 2008 and July 2021. Recipient and donor characteristics, operative data, type of reconstruction, and recipient outcomes were analyzed. The primary outcomes were the incidence of developing delayed graft function (DGF) and/or a vascular or urological complication within 12 months post-transplant.

Results: Seventy-three LDKT recipients of MRA donor allografts were evaluated. Two renal arteries (RA) were encountered in 62 allografts (84.9%) and three RA in 11 allografts (15.1%). Renal artery reconstruction was performed in 95.8% (70/73) of patients. Eighteen different reconstruction techniques of MRA were utilized, the most common being side-to-side anastomosis in allografts with two RA (N = 44) and side-to-side-to-side anastomosis in allografts with three RA (N = 4). Interposition grafting was performed in seven cases (9.6%). A single ostium was created in 69 cases (94.5%), and the median warm ischemia time was 27 (range 20–42) minutes. None of the patients developed DGF or post-operative vascular or urological complications. Median creatinine at 3, 6, and 12 months post-transplant remained stable at 1.1 mg/dl. With a median follow-up of 30.4 months post-transplant, only one graft failure has been observed–death-censored graft survival was 98.6%.

Conclusion: Complex reconstruction techniques to create a single renal artery ostium for graft implantation anastomosis in allografts with MRA show acceptable warm ischemic times, with no increased risk of post-operative vascular or urological complications.

Description and Outcomes of Three Different End-to-Side Microsurgical Techniques for the Anastomosis of Accessory Renal Artery With the Dominant Renal Artery in Kidney Transplantation

BACKGROUND

In this study, we compared the outcomes of three different surgical microscope-assisted end-to-side anastomosis techniques between the dominant and accessory renal arteries during living donor kidney transplant.

METHODS

The demographics, serum creatinine levels, warm and cold ischemia times, rate of complications, and incidence of delayed graft function of 135 kidney recipients were analyzed according to the type of arterial anastomosis. Group A (n = 98) had one dominant renal artery (DRA) with one end-to-side anastomosis to the external iliac artery (EIA) using a surgical microscope. Group B (n = 17) had one DRA plus one accessory renal artery (ARA) with two separate end-to-side anastomoses to the EIA using a surgical microscope. Group C (n = 20) had one DRA with end-to-side anastomosis to the EIA and one ARA with an ex vivo on-bench end-to-side anastomosis to the DRA using a surgical microscope.

RESULTS

Compared with groups A and B, the cold ischemia time and the rate of delayed graft function were significantly higher in group C (P ≤ .001). At 6 months after transplant, group B demonstrated a higher creatinine value (2.40 ± 3.41 mg/dL) than group A and group B (P = .032). Also, the decrease in creatinine at postoperative month 6 was limited in group B as compared with groups A and C.

CONCLUSIONS

An end-to-side anastomosis between ARA (group B) and DRA (group A) of the kidney graft using a surgical microscope on the bench ex vivo results in superior outcomes. Single arterial anastomosis techniques are associated with a better function in a 6-month follow-up than two separate arterial anastomoses.

Does the Side Matter? A Retrospective Cohort Study Comparing Left and Right Pure Laparoscopic Donor Nephrectomies

OBJECTIVES

Right laparoscopic donor nephrectomy (RLDN) is no longer regarded inferior to left LDN (LLDN). However, this knowledge is based on many studies suffering from inherent learning curves, center-specific imbalances, and different laparoscopic techniques.

METHODS

Pure LDNs at a high-volume referral center from 2011 to 2016 were retrospectively analyzed. Patient, graft characteristics, outcomes of LDNs, and corresponding open kidney transplantations were compared between LLDN and RLDN including a follow-up.

RESULTS

160 (78.4%) LLDNs and 44 (21.6%) RLDNs only differed regarding graft characteristics, as more right grafts had multiple veins (34.1 vs. 6.9%, p < 0.001) and worse scintigraphic function (44 vs. 51%, p < 0.001). RLDNs were shorter (201 vs. 220 min, p = 0.032) with longer warm ischemia time (165 vs. 140 s, p < 0.001), but left grafts were transplanted faster (160 vs. 171 min, p = 0.048). Recipients of right kidneys had more postoperative complications (grade 3: 25.6 vs. 11.3%, p = 0.020). At a follow-up of 45 (range 6-79) months, neither the kidney function, nor death-censored graft (5-year: LLDN 89 vs. 92%, p = 0.969) and patient survival (5-year: LLDN 95 vs. 98%, p = 0.747) differed.

CONCLUSIONS

Pure LLDN and RLDN can have different outcomes at high-volume centers, especially higher complications for recipients of right grafts. However, long-term function and graft survival are the same irrespective of the chosen side.

"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.

Step-by-step Development of a Cold Ischemia Device for Open and Robotic-assisted Renal Transplantation

BACKGROUND

Kidney transplantation (KT) is the best renal replacement treatment. The rewarming time is associated with ischemia/reperfusion damage. In both the open (open KT [OKT]) and the robotic (robotic-assisted KT [RAKT]) approaches, ice slush is used to maintain graft temperature (T°) below 20 °C. This may result in nonhomogeneous graft T° maintenance and, particularly during RAKT where the graft is completely inside the abdominal cavity, rises concerns regarding systemic hypothermia.

OBJECTIVE

To design a cold ischemia device (CID) to maintain a constant and homogeneous low graft T° during surgery.

DESIGN, SETTING, AND PARTICIPANTS

In IDEAL phase 0, a CID was developed and tested to determine its cooling effect on the kidney inside a closed system at 37.5 °C, by comparing it with kidney alone versus a gauze-jacket filled with ice slush. The CID was evaluated in pigs undergoing OKT and RAKT, assessing feasibility and adverse reactions. In IDEAL phase 1, the CID was tested in human OKT and RAKT.

SURGICAL PROCEDURE

OKT and RAKT.

MEASUREMENTS

In all phases, T° was evaluated at scheduled time points.

RESULTS AND LIMITATIONS

In the preliminary tests of IDEAL phase 0, the CID was able to maintain a low graft T° and superiority to other groups (p =  0.002). In the in vivo animal model, the CID maintained a low and constant graft T° in OKT (n = 3) and RAKT (n = 3), with a mean T° at 50 min of 10.8 °C and 14.9 °C, respectively. IDEAL phase 1 demonstrated feasibility of both approaches (OKT, n = 2 and RAKT, n = 3) using the CID, and graft T° never exceeded 20 °C (mean T°: OKT 15.7 °C vs RAKT 18.3 °C). No complications were recorded. The main limitation consists in the low number of participants.

CONCLUSIONS

The CID assured a constant low graft T° during rewarming time, in both OKT and RAKT.

PATIENT SUMMARY

A cold ischemia device (CID) is the first step toward a feasible, safe, and reproducible method to maintain a low graft temperature during surgery. The employment of a CID may optimize the functional outcomes.

[The first 50 robot-assisted donor nephrectomies : Lessons learned]

Hintergrund

Die minimal-invasive Donornephrektomie (DN) ist inzwischen operativer Standard, bezüglich der Rolle von roboterassistierten Verfahren gibt es bisher keinen Konsens.

Fragestellung

Die ersten 50 transperitonealen roboterassistierten Donornephrektomien (RDN) einer urologischen Universitätsklinik in Deutschland wurden retrospektiv ausgewertet.

Material und Methoden

Patientencharakteristika, intra- und postoperative Parameter wurden erfasst und die Nierenfunktion in einem 5‑jährigen Follow-up ausgewertet. Signifikante Prädiktoren für die Nierenfunktion bei Entlassung und ein Jahr postoperativ wurden in einem multivariablen Regressionsmodell bestimmt.

Ergebnisse

Die RDN hat exzellente Ergebnisse mit niedriger Komplikationsrate, kurzer warmer (WIZ) und kalter Ischämiezeit (KIZ) sowie geringem Blutverlust und kurzer Patientenverweildauer. Die Seite der Nierenentnahme hat hierauf keine Auswirkungen. Nach RDN sind etwa 50 % der Spender formal niereninsuffizient, was aber zumeist ohne Relevanz ist, weil sich die Nierenfunktion der Spender im Follow-up nicht weiter verschlechtert. Die postoperative Nierenfunktion lässt sich bei der RDN mithilfe der präoperativen eGFR (errechnete glomeruläre Filtrationsrate) und dem Spenderalter sehr gut vorhersagen.

Schlussfolgerungen

Die robotische DN stellt eine sehr gute Alternative zu anderen minimal-invasiven Operationsverfahren dar, die von Beginn an exzellente operative Ergebnisse ermöglicht.

Laparoscopic Live Donor Nephrectomy: Experience of High-Volume Center with 2,477 Cases

OBJECTIVE

Donors' health and safety are mandatory in the living-donor kidney transplantation procedure. Laparoscopic live donor nephrectomy (LLDN) provides an increase in donor numbers with its benefits and becomes a standard of care. We aimed to explain the results, complication rates, tips, and tricks of the largest number of LLDN case series ever performed in the literature.

MATERIALS AND METHODS

Between August 2012 and December 2019, 2,477 live donor case files were analyzed retrospectively. Age, gender, hospitalization times, body mass index, warm ischemia times, operation times, numbers of arteries, side of the kidneys, and complications were noted.

RESULTS

1,421 (57.4%) of 2,477 donors were female (p = 0.007). Operation times and warm ischemia times were found longer in right-sided LLDN and donors with multiple renal arteries (p = 0.046, <0.001, and <0.001, respectively). Obesity (BMI >30 kg/m2) did not affect warm ischemia times while prolonging the operation times (p = 0.013). Hospitalization times and numbers of complications were higher in obese donors.

CONCLUSIONS

LLDN seems to be a reliable solution with fewer complications and higher satisfaction rates. We hope to illuminate the way with tips and trick points for beginner transplant surgeons based on the experience obtained from 2,477 LLDN cases.

A Standardized Warm Ischemia Time for the Induction of Injury in Murine Kidney Transplants

One of the cornerstone research models used in our laboratories is the induction of ischemic injury through cold ischemia followed by warm ischemia to donor kidneys to mimic the clinical realities of transplantation. The experimental design of the present study included bilateral nephrectomies on the day of syngeneic kidney transplant, with serum creatinine measured 24 hours postoperatively to measure acute function. Cold ischemia time in these experiments was always 30 minutes, and warm ischemia time was not standardized but always recorded. It became apparent that some transplanted kidneys that should have displayed injury were producing close to normal serum creatinine levels on postoperative day 1. In reviewing our data, we found a potential correlation between warm ischemia time and serum creatinine, in particular a significant proportion of low serum creatinine results (0.48 ± 0.26 mg/dL vs 1.99 ± 1.11 mg/dL; P < .05) was associated with warm ischemia times that were significantly shorter than our historical average (29.2 ± 2.7 min vs 35.7 ± 2.2 min; P < .05). The kidneys with lower serum creatinine also displayed lower apoptosis and brush border injury scores and fewer tubular casts. Therefore, we concluded that establishing a minimum warm ischemia time was just as important as standardized cold ischemia time to ensure consistent injury in this model.

Grafts With Multiple Renal Arteries in Kidney Transplantation

BACKGROUND

Renal grafts with multiple renal arteries (MRA) are a compelling issue in surgery of kidney transplantation. Transplantations using "grafts with MRA" have conflicting results. Here, we present our experiences on the issue.

METHOD

This is a single-center, observational, descriptive study. One hundred ninety-nine patients with end-stage renal disease received a kidney graft from their living- or deceased-related donors in our center between July 2016 and May 2017. We included all recipients to the study. Patients were divided into the following 2 groups: Group 1, recipients who received a renal graft with single renal artery, and Group 2, recipients who received a renal graft with MRA. Groups were compared for estimated glomerular filtration rates (months 1-3 and 12), delayed graft function, and graft survival. Data were analyzed by using SPSS for Windows version 15.

RESULTS

One hundred ninety-five recipients with all documented data were analyzed. Graft function was compared between 2 groups in months 1, 3, and 12 and found both to have similar outcomes. MRA has been indicated to have no impact on delayed graft function, higher risk for vascular injury, and biopsy-proven acute tubular necrosis. Also, anastomosis sides have been found to have no importance on graft function in recipients with MRA (P > .05 between all sides).

CONCLUSION

Our study indicates grafts with MRA and grafts with a single renal artery have comparable results in the first post-transplant year.

Review 1: Lung transplant-from donor selection to graft preparation

For various end-stage lung diseases, lung transplantation remains one of the only viable treatment options. While the demand for lung transplantation has steadily risen over the last few decades, the availability of donor grafts is limited, which have resulted in progressively longer waiting lists. In the early years of lung transplantation, only the 'ideal' donor grafts are considered for transplantation. Due to the donor shortages, there is ongoing discussion about the safe use of 'suboptimal' grafts to expand the donor pool. In this review, we will discuss the considerations around donor selection, donor-recipient matching, graft preparation and graft optimisation.

Robot-Assisted versus Laparoscopic Donor Nephrectomy: A Comparison of 250 Cases

Living kidney donation is the best treatment for end-stage renal disease, however, the best surgical approach for minimally-invasive donor nephrectomy (DN) is still a matter of debate. This bi-centric study aimed to retrospectively compare perioperative outcomes and postoperative kidney function after 257 transperitoneal DNs including 52 robot-assisted (RDN) and 205 laparoscopic DNs (LDN). As primary outcomes, the intraoperative (operating time, warm ischemia time (WIT), major complications) and postoperative (length of stay, complications) results were compared. As secondary outcomes, postoperative kidney and graft function were analyzed including delayed graft function (DGF) rates, and the impact of the surgical approach was assessed. Overall, the type of minimally-invasive donor nephrectomy (RDN vs. LDN) did not affect primary outcomes, especially not operating time and WIT; and major complication and DGF rates were low in both groups. A history of smoking and preoperative kidney function, but not the surgical approach, were predictive for postoperative serum creatinine of the donor and recipient. To conclude, RDN and LDN have equivalent perioperative results in experienced centers. For this reason, not the surgical approach, but rather the graft- (preoperative kidney function) and patient-specific (history of smoking) aspects impacted postoperative kidney function.

Identification of Factors Associated With Acute Tubular Necrosis Following Kidney Transplant in Northern Mexico: Increased Risk With Cold Ischemia After 8 Hours

AIM

To identify potential risk factors associated with the incidence of acute tubular necrosis (ATN) following kidney transplant in a sample of patients from northern Mexico.

METHODS

Secondary analysis of data extracted from clinical files of patients who underwent a kidney transplant between 2000 and 2017 at Christus Muguerza Hospital in the city of Chihuahua. The final sample with complete data included 485 patients. ATN was diagnosed in 13.2% of patients using pathologic, clinical, and laboratory criteria. Adjusted odds ratio (ORs) with 95% CIs from multivariate binary logistic regression were used to identify predictors of ATN.

RESULTS

Only 4 of 21 variables analyzed remained statistically significant in the final adjusted model. Cold and warm ischemia followed time-trend patterns with higher odds with longer ischemia times. For cold ischemia, compared with 0 to 240 minutes, ORs were 1.32 (95% CI, 0.49-3.51) for 241-480 minutes, 4.87 (95% CI, 2.29-10.3) for 481-960 minutes, and 10.0 (95% CI, 2.86-35.0) for > 960 minutes; for warm ischemia, compared with 40 to 59 minutes, these were 6.27 (95% CI, 1.95-20.8) for 60-70 minutes and 10.32 (95% CI, 1.95-54.4) for 71-110 minutes. Hypotension during surgery was associated with a higher chance of ATN (OR, 15.9; 95% CI, 4.97-50.9). When the recipients' age was 30 years or older, the probability also increased significantly (OR, 2.88; 95% CI, 1.09-7.57). The final model fitted well and explained 27% of the probability to develop ATN after a kidney transplant.

CONCLUSION

Shortening the duration of ischemia and avoiding hypotension during surgery is essential to prevent ATN following a kidney transplant.

Predictive Factors for Improved Renal Function in Renal Transplantation Recipients

OBJECTIVE

The purpose of this study is to analyze varying predictive factors for improved graft function among renal transplant recipients.

METHODS

Two hundred eleven consecutive donor and recipient pairs who underwent renal transplantation between January 2011 and December 2015 were enrolled in our study. Factors that affected renal graft function were analyzed. Statistical analyses were performed using SPSS version 16.0 software (SPSS Inc, Chicago, IL, United States).

RESULTS

The mean age of donors in years was 30 (range, 17-62), with a mean body mass index (BMI) of 23.20 kg/m² (range, 16.10-39.50). Mean total warm ischemic time in minutes was 44.80 (range, 26.10-83.45). The mean age of the recipients in years was 48 (range, 12-78) with a mean BMI of 22 kg/m² (range, 14.80-37.30). Estimated glomerular filtration rate at 6 and 12 months post-transplantation were 69 mL per minute per 1.73 m² (range, 10-137) and 65 (range, 16-110), respectively. Based on several parameters, there was no significant factor that improved renal graft function at 6 and 12 months after transplant. Total warm ischemic time almost showed statistical significance in predicting improved renal graft function after transplant. Future study with a longer period of observation and a larger sample size should be done for further investigation.

CONCLUSIONS

Total warm ischemic time is a promising parameter to predict improved renal graft function post-transplantation.

Implantation Warm Ischemia Time in Kidney Transplant Recipients: Defining Its Limits and Impact on Early Graft Function

Background

Prolonged cold ischemia is an established risk factor for poor early graft function (EGF). However, warm ischemia incurring during graft implantation has received little attention regarding its possible detrimental effect on EGF. The aim of our study was to examine the impact of recipient warm ischemia time on EGF.

Material/Methods

The data of 102 consecutive kidney transplants were analyzed to determine the association between duration of graft implantation time (IT) and EGF. Recipient IT groups were (GI) up to 45 min, (GII) 45–60 min, and (GIII) >60 min. EGF was categorized as immediate (IGF), slow (SGF), or delayed graft function (DGF). In recipients with IGF, graft function was further assessed by time needed for reduction in serum creatinine by 50% (SC50) of pre-transplant value, and serum creatinine on day 7 (SCD7).

Results

Of a total of 102 recipients, 55 (55%) were in GI, 33 (32%) were in GII, and 14 (13%) were in GIII. Factors prolonging IT were recipient body mass index (BMI) (p=0.02) and multiple arteries in donor kidneys (p<0.01). No recipients in GI had DGF or SGF, while 2 in GII had DGF, and 5 patients in GIII had poor EGF. SC50 was significantly longer in GIII and GII versus GI (40.8±42.4 and 32.8±20.4 vs. 22.2±17.2 [p=.02, p≤.01]), respectively. Mean SCD7 was also significantly higher in GIII and GII versus GI. The mean last serum creatinine was comparable among all groups.

Conclusions

IT of more than 45 min was a risk factor for poor EGF, but achieved statistical significance only when it exceeded 60 min. Longer IT also significantly slowed the fall in SC50, and led to a higher SCD7. However, poor EGF and suboptimal early SC trends had little long-term effect on serum creatinine.

Warm Ischemia Time at Vascular Anastomosis is an Independent Predictor for Delayed Graft Function in Kidney Transplant Recipients

OBJECTIVES

Delayed graft function after kidney transplant can affect patient and graft survival, resulting in prolonged hospital stay and need for dialysis. Ischemia times during organ procurement and reanastomosis at transplant are key factors in delayed graft function.

MATERIALS AND METHODS

We analyzed all living- and deceased-donor renal transplants in Ireland over a 33-month period, with effect of warm ischemia time during anastomosis on delayed graft function being the primary outcome. We performed statistical regression analyses to account for confounding variables. Patients had identical surgical technique and immunosuppression protocols.

RESULTS

Of 481 transplants during the study period, 20 patients were excluded because of paired-kidney exchange, nephron dosing transplant, or simul-taneous pancreas-kidney transplant. In the donor pool, 70% were donors after brainstem death, 3.6% were donors after cardiac death, and 26% were living donors. All living donors were direct altruistic donors and underwent stringent assessment via the ethics committee and multidisciplinary team meeting. Of living donors, 8% were not related. These were true altruistic donors who were acquaintances of the recipients and volunteered themselves for assessment. They were assessed in accordance with the declaration of Istanbul and received no compensation of any kind for donation. Of total patients, 18% had delayed graft function, defined as need for dialysis within 7 days of transplant. Warm ischemia time during anastomosis significantly affected risk of delayed graft function but not graft survival or function at 3 months. This factor did not correlate with hospital stay duration. Time on dialysis and recipient weight significantly correlated with risk of delayed graft function.

CONCLUSIONS

Our findings support a role for minimizing warm ischemia time during anastomosis to reduce delayed graft function and need for dialysis in the perioperative period. However, a longer time does not appear to affect creatinine levels and therefore graft function at 3 months.

Pharmacological Protection of Kidney Grafts from Cold Perfusion-Induced Injury

One of the greatest challenges facing the field of organ transplantation is the shortage of donor organs for transplantation. Renal transplantation increases quality of life and survival of patients suffering from end-stage renal disease. Although kidney transplantation has evolved greatly over the past few decades, a not insignificant amount of injury occurs to the kidney during recovery, preservation, and implantation and leads to the loss of function and loss of years of dialysis-free living for many patients. The use of kidneys from expanded criteria donors (ECD) and donation after circulatory determination of death (DCDD) has been adopted partly in response to the shortage of donor kidneys; however these kidneys are even more susceptible to ischemic injury. It has been shown that matrix metalloproteinases (MMPs) and reactive oxygen species (ROS) are involved in mechanisms of injury to the transplant kidney. There is also some evidence that inhibition of MMP activity and/or ROS production can protect the kidney from injury. We review possible pharmacological strategies for protection of kidney graft from injury during recovery, preservation, and implantation.

First Canadian experience with robotic laparoendoscopic single-site vs. standard laparoscopic living-donor nephrectomy: A prospective comparative study

INTRODUCTION

We aimed to compare the outcomes of robotic laparoendoscopic single-site living donor nephrectomy (R-LESS LDN) vs. standard laparoscopic living donor nephrectomy (LLDN).

METHODS

Between October 2013 and November 2015, 39 patients were allocated to either standard LLDN (n=25) or R-LESS LDN (n=14). Patient demographics, perioperative outcomes, analgesic requirement, visual analogue scale of pain at postoperative days 1, 3, 7, and 30, and a health-related quality of life and body image questionnaire were prospectively collected.

RESULTS

There were no significant differences in demographics and intraoperative outcomes between the two cohorts. The R-LESS LDN cohort had lower analgesic requirement (p=0.002) and lower visual pain scores on days 1 and 3 (p=0.001). Additionally, body image and satisfaction scores in the R-LESS group were also superior compared to the LLDN cohort (p=0.008). There was no significant difference in the postoperative complications according to the Clavien-Dindo system. Recipient graft functional outcomes were equivalent.

CONCLUSIONS

This is the first evidence that R-LESS LDN is safe and associated with comparable surgical and early functional outcomes compared to LLDN, while pain, donor body image, and satisfaction scores were improved compared to LLDN.

Outcomes of Kidney Transplantation by Using the Technique of Renal Artery Anastomosis First

Introduction

The surgical technique for kidney transplantation has been well established: the renal vein is anastomosed first, followed by renal artery anastomosis. Alternatively, the renal artery can be anastomosed first and then the renal vein for kidney transplantation. However, there is a lack of data on the outcomes of kidney transplantation by using this alternative approach. The objective of this paper was to review the outcomes of kidney transplant by using this approach.

Methods

A review of 205 consecutive kidney transplants was conducted. All kidney transplants were performed by doing renal artery anastomosis first and then the renal vein. Data were collected, including vascular/urological complications and kidney graft function.

Results

All transplants were performed successfully with no occurrence of renal artery/vein thrombosis and urine leakage. There were five cases of renal artery stenosis that were managed with endovascular intervention. There was no recurrence on follow-up. One ureteric stenosis required surgical reconstruction.

Conclusions

This alternative vascular anastomotic technique is efficient and safe. It avoids flip-flopping the kidney graft during the vessel anastomoses and may be more practical in minimally invasive surgery for a kidney transplant due to the space constraint.

Implantation of Right Kidneys: Is the Risk of Technical Graft Loss Real?

BACKGROUND

The left kidney (LK) is preferred by transplant surgeons, because its vein is always of good length and has a thick wall that enables safe suturing. On the other hand, the right renal vein is generally shorter and thinner walled, and well known for its technical difficulty during venous anastomosis, and can result in graft loss. We examined our living (LD) and deceased donor (DD) recipient data and compared the incidence of technical graft loss and early graft function in right and left kidneys.

METHODS

A cohort of 58 adult and pediatric recipients received an LD or DD kidney between January 2015 and December 2016. The donor and recipient data were retrieved and retrospectively analyzed. Technical graft loss was defined as graft thrombosis within the 7 days after transplant.

RESULTS

Right kidneys (RKs) were not a risk factor for technical graft loss, and no graft was lost for technical reasons in either LD or DD transplants. Early graft function in LK and RKs was also comparable in the LD cohort, and there were no LKs in the DD cohort.

CONCLUSION

Based on our data, the use of RKs was not a risk factor for technical graft loss and early graft function was comparable to LKs.

Ischemic Conditioning in Kidney Transplantation

Ischemia–reperfusion injury is a composite of the injury sustained during a period of reduced or absent blood flow to a tissue or organ and the additional insult sustained on reperfusion, which limits the amount of tissue that can be salvaged. Ischemia–reperfusion injury is the predominant insult during kidney transplantation, contributing to graft dysfunction, increased rates of acute rejection, and reduced rejection-free graft survival. In this review, we discuss the potential therapeutic benefits of a cost-effective and low-risk intervention, ischemic preconditioning, and its potential for improving kidney function following transplantation.

Minimally Invasive, Laparoscopic, and Robotic-assisted Techniques Versus Open Techniques for Kidney Transplant Recipients: A Systematic Review

CONTEXT

Literature on conventional and minimally invasive operative techniques has not been systematically reviewed for kidney transplant recipients.

OBJECTIVE

To systematically evaluate, summarize, and review evidence supporting operating technique and postoperative outcome for kidney transplant recipients.

EVIDENCE ACQUISITION

A systematic review was conducted in PubMed-Medline, Embase, and Cochrane Library between 1966 up to September 1, 2016, according to Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. Articles were included and scored by two independent reviewers using Group Reading Assessment and Diagnostic Evaluation (GRADE), Newcastle-Ottawa Quality Assessment Scale (NOS), and Oxford guidelines for level of evidence. Main outcomes were graft survival, surgical site infection, incisional hernia, and cosmetic result. In total, 18 out of 1954 identified publications were included in this analysis.

EVIDENCE SYNTHESIS

Included reports described conventional open, minimally invasive open, laparoscopic, and robotic-assisted techniques. General level of evidence of included studies was low (GRADE: 1-3; NOS: 0-4; and Oxford level of evidence: 4-2). No differences in graft or patient survival were found. For open techniques, Gibson incision showed better results than the hockey-stick incision for incisional hernia (4% vs 16%), abdominal wall relaxation (8% vs 24%), and cosmesis. Minimally invasive operative recipient techniques showed lowest surgical site infection (range 0-8%) and incisional hernia rates (range 0-6%) with improved cosmetic result and postoperative recovery. Disadvantages included prolonged cold ischemia time, warm ischemia time, and total operation time.

CONCLUSIONS

Although the level of evidence was generally low, minimally invasive techniques showed promising results with regard to complications and recovery, and could be considered for use. For open surgery, the smallest possible Gibson incision appeared to yield favorable results.

PATIENT SUMMARY

In this paper, the available evidence for minimally invasive operation techniques for kidney transplantation was reviewed. The quality of the reviewed research was generally low but suggested possible advantages for minimally invasive, laparoscopic, and robot-assisted techniques.

The influence of warm ischemia elimination on kidney injury during transplantation - clinical and molecular study

Kidney surface cooling was used during implantation to assess the effect of warm ischemia elimination on allograft function, histological changes and immune-related gene expression. 23 recipients were randomly assigned to a group operated on with kidney surface cooling during implantation (ice bag technique, IBT group), and the other 23 recipients receiving the contralateral kidney from the same donor were operated on with a standard technique. Three consecutive kidney core biopsies were obtained during the transplantation procedure: after organ recovery, after cold ischemia and after reperfusion. Gene expression levels were determined using low-density arrays (Format 32, TaqMan). The IBT group showed a significantly lower rate of detrimental events (delayed graft function and/or acute rejection, p = 0.015) as well as higher glomerular filtration rate on day 14 (p = 0.026). A greater decrease of MMP9 and LCN2 gene expression was seen in the IBT group during total ischemia (p = 0.003 and p = 0.018). Elimination of second warm ischemia reduced the number of detrimental events after kidney transplantation, and thus had influence on the short-term but not long-term allograft function. Surface cooling of the kidney during vascular anastomosis may reduce some detrimental effects of immune activation resulting from both brain death and ischemia-reperfusion injury.

Absence of the Effect of Pretransplant Body Mass Index on Post Kidney Transplant Outcomes

CONTEXT

Obesity has been reported as risk factor for reduced posttransplant graft and patient survival and increased delayed graft function (DGF).

OBJECTIVE

The purpose of this work is to analyze the effect of body mass index (BMI) on defined transplant outcomes in patients transplanted under defined guidelines in a kidney transplant program.

DESIGN

Review of a prospectively collected database in renal transplant recipients receiving rabbit antithymocyte globulin induction, mycophenolate mofetil, tacrolimus, and early corticosteroid withdrawal between 2001 and 2011.

SETTING

This review was conducted in a single abdominal transplant program in the United States.

MAIN OUTCOME MEASURES

Primary outcome was death-censored graft survival categorized by posttransplant body mass groups. Secondary outcomes included DGF as well as patient survival.

RESULTS

Four hundred sixty seven patients were identified. No difference was observed in graft survival or DGF between BMI groups. One-year, death-censored graft survival and patient survival rates ranged from 97.5% to 100% and 96.6% to 100%, respectively. Delayed graft function was uncommon across all BMI groups, ranging from 5.3% to 9.1%, with the lowest incidence in patients with a BMI ≥ 35 kg/m(2). Biopsy-proven acute rejection rates at 1 year were similar across all groups (10.1%-14%) as were estimated glomerular filtration rates were at 1, 3, and 5 years.

CONCLUSION

Our results do not show an effect of BMI on posttransplant outcomes, suggesting that relaxation of BMI criteria may be warranted for recipient selection.

Prolonged warm ischemia time is associated with graft failure and mortality after kidney transplantation

Warm ischemia time is a potentially modifiable insult to transplanted kidneys, but little is known about its effect on long-term outcomes. Here we conducted a study of United States kidney transplant recipients (years 2000-2013) to determine the association between warm ischemia time (the time from organ removal from cold storage to reperfusion with warm blood) and death/graft failure. Times under 10 minutes were potentially attributed to coding error. Therefore, the 10-to-under-20-minute interval was chosen as the reference group. The primary outcome was mortality and graft failure (return to chronic dialysis or preemptive retransplantation) adjusted for recipient, donor, immunologic, and surgical factors. The study included 131,677 patients with 35,901 events. Relative to the reference patients, times of 10 to under 20, 20 to under 30, 30 to under 40, 40 to under 50, 50 to under 60, and 60 and more minutes were associated with hazard ratios of 1.07 (95% confidence interval, 0.99-1.15), 1.13 (1.06-1.22), 1.17 (1.09-1.26), 1.20 (1.12-1.30), and 1.23 (1.15-1.33) for the composite event, respectively. Association between prolonged warm ischemia time and death/graft failure persisted after stratification by donor type (living vs. deceased donor) and delayed graft function status. Thus, warm ischemia time is associated with adverse long-term patient and graft survival after kidney transplantation. Identifying strategies to reduce warm ischemia time is an important consideration for future study.

Renal Transplantation by Automatic Anastomotic Device in a Porcine Model

Automatic vascular staplers for vascular anastomoses in kidney transplantation may dramatically reduce the operative time and, in particular, warm ischemia time, thus increasing the outcome of transplantation. Ten pigs underwent kidney auto-transplantation by automatic anastomotic device. Kidneys were collected by laparotomy with selective ligations at the renal hilum and perfused with cold storage solution. To overcome the shortage in length of renal hilum, a tract of the internal jugular vein was harvested to increase the length of the vessels. The anastomoses were totally performed by the use of the anastomotic device. On 10 kidney transplants, nine were successful and no complications occurred. Renal resistive indexes showed a slight increase in the immediate postoperative period returning normal at 10 days of follow-up. We demonstrated the possibility to perform renal vascular anastomoses by means of an automatic anastomotic device. This instrument developed for coronary bypass surgery by virtue of the small caliber of the vessels could be adopted on a larger scale for renal transplantation. The reduced warm ischemia time needed for anastomosis may help to achieve a better outcome for the graft and expand the pool of marginal donors in renal transplantation.

Utility of inguinal incision in retroperitoneoscopic live donor nephrectomy

BACKGROUND

Retroperitoneoscopic live donor nephrectomy has been performed in many countries. The purpose of this study was to evaluate the inguinal incision as a route for hand-assisted manipulation and allograft retrieval.

METHODS

From April 2011 to June 2012, a prospective clinical study of 21 cases of retroperitoneal live donor nephrectomy was performed at our hospital. All donors were grouped in a test group (n = 11, inguinal incision) or a control group (n = 10, lumbar incision). The operative time, warm ischaemia time, blood loss, hospital stay, cosmetic satisfaction, incision complications, and recipient's serum creatinines were compared between groups.

RESULTS

All 21 cases of retroperitoneal live donor nephrectomy were accomplished successfully without serious complications. There was no difference in blood loss and operative time between groups. The mean warm ischaemic time and hospital stay was shorter (P < 0.01), and satisfaction with cosmesis was greater (P < 0.05) in the test group. The abdominal asymmetry (4/10) and wound dehiscence occurred only in the control group. The recipient's serum creatinine was lower in the test group at 1 day (P < 0.01) and 3 days (P < 0.05) after transplantation.

CONCLUSION

The inguinal incision offers an ideal route for hand-assisted manipulation and allograft retrieval during retroperitoneoscopic live donor nephrectomy, and has a potential to be generally applied in the future.

The impact of vascular anastomosis time on early kidney transplant outcomes

Background

Most studies have found cold ischemic time to be an important predictor of delayed graft function in kidney transplantation. Relatively less is known about the warm time associated with vascular anastomosis and early outcomes.

Methods

A retrospective cohort of 298 consecutive solitary deceased donor kidney recipients from January 2006 to August 2012 was analyzed to examine the association between anastomosis time and delayed graft function (need for dialysis) and length of hospital stay.

Results

Delayed graft function (DGF) was observed in 56 patients (18.8%). The median anastomosis time was 30 minutes (interquartile range 24, 45 minutes). Anastomosis time was independently associated with DGF in a multivariable, binary logistic regression analysis (odds Ratio (OR) 1.037 per minute, 95% CI 1.016, 1.057, P = 0.001). An anastomosis time >29 minutes was also associated with a 3.5 fold higher (OR 3.5, 95% CI 1.6, 7.3, P = 0.001) risk of DGF. Median days in hospital was 9 (interquartile range 7, 14 days). Every 5 minutes of longer anastomosis time (0.20 days per minute, 95% CI 0.13, 0.27, P <0.001) was associated with 1 extra day in hospital in a multivariable linear regression model. An anastomosis time >29 minutes was associated with 3.8 (95% CI 1.6, 6.0, P <0.001) more days in hospital.

Conclusion

Anastomosis time may be an underappreciated but modifiable variable in dictating use of hospital resources. The impact of anastomosis time on longer term outcomes deserves further study.