The impact of vascular anastomosis time on early kidney transplant outcomes

Evidence-Based Complementary Benefit of the Vascular Surgeon Among the Team of Renal Transplantation; a Single Center Experience

BACKGROUND

In a kidney transplant tertiary referral center; we compared 3 operating team configurations of different surgical specialties to highlight the effect of the operating surgeon's specialty on various operative details and procedural outcome.

METHODS

A total of 50 cases of living donor transplantations were divided into 3 main groups according to the operating surgeons' specialty, the first group (A) includes 12 patients exclusively operated on by urologists with advanced training in transplantation, the second group (B) includes 35 patients operated by combined surgical specialties; a urologist and a vascular surgeon both with advanced transplantation training, and a third group (C) includes 3 cases where the transplant operation commenced with operating urologists as in group (A) but required intraoperative urgent notification of a vascular surgeon to manage unexpected intraoperative technical difficulties or major complications. Cases were studied according to operative details, anastomosis techniques, ischemia times, total procedure time, recovery of urinary output, intensive care unit (ICU) stay, postoperative surgical complications and serum creatinine level for up to 3 years of follow-up.

RESULTS

Study of operative details revealed that total duration of graft ischemia was significantly shorter in group (B) and significantly longer in group (C) (P value 0.001), Total procedural duration also varied significantly between the 3 groups, group (B) being the shortest while group (C) was the longest (P value less than 0.001). Technically; group (A) used only end to end arterial anastomosis as a standard technique, while group (B) used both end-to-end and end-to-side anastomoses as required per each case. End to side anastomosis in group (B) yielded better immediate graft response in the form of change in color, texture, earlier and more profuse postoperative urine volumes (P value 0.025). Furthermore, anastomosis to common and external iliac arteries (group B) yielded earlier and higher urine volumes than the internal iliac artery (P values 0.024 and 0.031 respectively). Group (B) recorded significantly less postoperative perigraft hematomas and lymphoceles compared to the other 2 groups. Equal rates of urine leaks, ICU stay, creatinine levels, patient and grafts survival rates among groups (A) and (B), while postoperative recovery and ICU stay duration were more lengthy in the complicated group (C).

CONCLUSIONS

A vascular surgeon operating in a transplantation team would deal comfortably and efficiently with various vascular related challenges and complications, thus avoiding unnecessary time waste, complications and costs.

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.

Delayed Graft Function and the Renin-angiotensin System

Delayed graft function (DGF) is a form of acute kidney injury (AKI) and a common complication following kidney transplantation. It adversely influences patient outcomes increases the financial burden of transplantation, and currently, no specific treatments are available. In developing this form of AKI, activation of the renin-angiotensin system (RAS) has been proposed to play an important role. In this review, we discuss the role of RAS activation and its contribution to the pathophysiology of DGF following the different stages of the transplantation process, from procurement and ischemia to transplantation into the recipient and including data from experimental animal models. Deceased kidney donors, whether during cardiac or brain death, may experience activation of the RAS. That may be continued or further potentiated during procurement and organ preservation. Additional evidence suggests that during implantation of the kidney graft and reperfusion in the recipient, the RAS is activated and may likely remain activated, extrapolating from other forms of AKI where RAS overactivity is well documented. Of particular interest in this setting is the status of angiotensin-converting enzyme 2, a key RAS enzyme essential for the metabolism of angiotensin II and abundantly present in the apical border of the proximal tubules, which is the site of predominant injury in AKI and DGF. Interventions aimed at safely downregulating the RAS using suitable shorter forms of angiotensin-converting enzyme 2 could be a way to offer protection against DGF.

The Kidney Transplant: Maintaining Excellent Outcomes While Increasing Skills Acquisition

OBJECTIVE/BACKGROUND

Kidney transplantation is a complex operation that incorporates multiple fundamental surgical techniques and is an excellent opportunity for surgical skill development during residency training. We hypothesized that increasing resident competency, measured as anastomosis time, could be demonstrated while maintaining high-quality surgical outcomes during the learning process.

METHODS

We performed a retrospective cohort study of surgical resident involvement in kidney transplantation and recorded the anastomosis time. The study population comprised adult, single organ kidney transplants (n = 2052) at a large academic transplant center between 2006 and 2019. Descriptive statistics included frequencies, medians, and means. A mixed model of anastomosis time on number of procedures was fitted. Poisson models were fitted with outcomes of the number of patients with delayed graft function and number of patients that underwent reoperation postoperatively, with the exposure being number of kidney transplants performed by resident.

RESULTS

Results from the mixed model suggest that as the number of times a resident performs the surgery increases, the time to conduct the operation decreases with statistical significance. The Poisson regression demonstrated no significant relationship between the operative volume of a resident and postoperative complications.

CONCLUSION

This study demonstrated statistical evidence that with an increase in the number of renal transplantations performed by a surgical resident, anastomosis time decreased. It also demonstrated no significant relationship between number of kidney transplants performed by a resident and postoperative complications, suggesting that patient outcomes for this operation are not adversely affected by resident involvement.

High-Intensity Transient Signals Detected in a Renal Allograft

High-intensity transient signals (HITS) are signals recorded by the Doppler ultrasounds, reflecting either the passage of microemboli, both solid or gaseous in the vessels, or artifacts. Their identification during Duplex US highlights the need for further evaluation to rule out a potential embolic source. A 49-year-old female was referred to our hospital for renal transplantation. The Doppler ultrasound done on day 4 after the surgery revealed the presence of high-intensity transient signals (HITS) suggesting the passage of an emboli. Renal magnetic resonance angiography (MRA) confirmed the presence of peripheral parenchymal defects suggestive of a distal embolus. A better understanding and recognition of this radiological sign are essential in order to initiate appropriate patient management when needed. In this report, we review the importance of HITS and present a case in which HITS were detected in an unusual location: an allograft kidney artery.

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.

The Effect of Recipient Back-Table Duration on Graft Outcome of Deceased Donor Kidneys: A Single-Center Prospective Cohort Study

Background: Little is known about the influence of the duration of the kidney back-table preparation period and kidney temperature on graft outcomes after transplantation. The aim of this study is to investigate the back-table duration and its relation to graft outcome and the relation between kidney temperature and graft outcome. Methods: In this prospective cohort study, deceased donor kidney temperature is measured at fixed time points using an infrared thermometer during back-table preparation and transplantation. Additionally, the back-table duration is measured using a timer. Results: Between September 2020 and July 2021, 49 kidneys were prospectively included in this study. Median back-table duration was 33.7 (standard deviation ± 14.1) min and donor kidney temperature increased up to 14.9 °C (±2.8) after 60 min of back-table preparation. Mean implantation time was 24.9 (±7.6) min and kidney temperature increased up to 25.9 °C (±2.4) after 30 min of implantation time. Longer back-table duration was significantly associated with higher rates of delayed graft function (p = 0.037). However, this observation did not sustain at 3 and 6-months post-transplantation. No association was found between kidney temperature and graft outcomes. Conclusion: Longer back-table duration is significantly associated with DGF after deceased donor kidney transplantation. No association was observed between kidney temperature and graft outcomes of deceased donor kidneys.

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.

Anastomosis Time and Outcomes after Donation after Circulatory Death Kidney Transplantation

BACKGROUND

At every stage in the transplantation process for a deceased-donor kidney, time means ischemia. Donation after circulatory death (DCD) kidneys are already subject to warm ischemia in the donor, but another underappreciated component of warm ischemia time is the time required for anastomosis prior to reperfusion. We studied the effect of anastomosis time (AT) on outcomes after DCD kidney transplantation.

STUDY DESIGN

This is a retrospective study of the Scientific Registry of Transplant Recipients, including all US adult DCD kidney transplantation recipients from 2009 to 2015 (N = 6,397). Our exposure was AT (time out of cold storage until reperfusion, quartiles). Outcomes included delayed graft function (DGF), death-censored graft survival, and overall patient survival. Multivariable logistic and Cox regression quantified the association of AT with outcomes, adjusting for donor and recipient factors (including donor warm ischemia time).

RESULTS

AT accounted for 67% of total warm ischemia time on average, with a median AT of 38 minutes (median total warm ischemia 56 minutes). Longer AT (fourth [≥48min] vs first quartile [≤30min]) was associated with increased DGF (odds ratio = 1.19, p = 0.024) and increased graft failure (hazard ratio = 1.21, p = 0.043) but was not associated with patient survival. Comparing patients with the longest vs shortest AT, adjusted DGF incidence was 44.0% vs 36.7% (p = 0.024), and 5-year graft survival was 84.8% vs 88.2% (p = 0.004).

CONCLUSION

Prolonged AT is associated with worse graft outcomes in DCD kidney transplant recipients. Efforts to minimize rewarming during implantation and optimize AT may improve graft outcomes.

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.

Super-Minimal Incision Technique in Pediatric Kidney Transplantation: A Paired Kidney Analysis

BACKGROUND

Recently, the demand for minimally invasive techniques in kidney transplantation (MIKT) has increased. However, there is only a limited number of studies on MIKT, especially in pediatric kidney transplants. Hence, we evaluated whether there is a difference between the super-minimal incision technique in pediatric kidney transplantation (SMIPKT) and conventional kidney transplantation (CKT).

METHODS

Between December 2018 and November 2021, 34 patients who underwent pediatric kidney transplantation with a follow-up of 1 month were enrolled. A paired kidney analysis was performed to minimize donor variability and bias. The SMIPKT and CKT groups included 17 patients.

RESULTS

There was no difference in baseline clinical characteristics, including age, sex, the donor/ recipient weight ratio (DRWR), choice of dialysis modality, pretransplant dialysis time, BMI, renal artery number, cause of ESRD, DGF, length of the kidney and cold ischemic time, tacrolimus concentration at 3 and 7 days, serum creatinine at 1 month and postoperative complication rate between the SMIPKT and CKT groups (all P > 0.05). However, the length of the incision, operation time, intraoperative bleeding, postoperative drainage volume within 24 h and Vancouver scar scale at 1 month were statistically significant (all P < 0.05).

CONCLUSION

Compared with CKT, our results indicated that SMIPKT showed more satisfactory cosmetic results, shorter SMIPKT operating time, and reduced intraoperative bleeding and postoperative drainage volume within 24 h. There were also no statistical differences in postoperative complications. Hence, we suggest that SMIPKT is an appropriate method for pediatric kidney transplantation.

"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.

Early Transplant Arteriopathy in Kidney Transplantation

BACKGROUND

Early dysfunction of renal allografts may be associated with vascular injury, which raises the specter of active rejection processes that require medical intervention. In our practice, we have encountered patients who present with delayed graft function and demonstrate a unique pattern of endothelial cell injury that raises concern for rejection in their biopsy. Therefore, we sought to systematically determine the biopsy characteristics and outcome of these patients.

METHODS

During a 17-year period at the University of Washington in Seattle, United States, we identified 24 cases of a distinct arterial vasculopathy presenting in the first year posttransplantation. This early transplant arteriopathy (ETA) is characterized by endothelial cell swelling and intimal edema but without the intimal arteritis that defines vascular rejection.

RESULTS

Approximately 1% of transplant biopsies during the study period showed ETA, almost all of which were in deceased donor organs (96%), and most presented with delayed graft function (54%) or increased serum creatinine (38%) soon after transplantation (median 13 days; range, 5-139). In this study, 77% of patients were managed expectantly, with only 2 patients (7.6%) subsequently developing acute vascular rejection. Except for 1 patient who died, all patients had functioning allografts at 1 year follow-up.

CONCLUSION

Recognizing ETA and distinguishing it from vascular rejection is important to prevent over-treatment because most patients appear to recover allograft function rapidly with expectant management.

Protection From the Second Warm Ischemic Injury in Kidney Transplantation Using an Ex Vivo Porcine Model and Thermally Insulating Jackets

BACKGROUND

Kidney transplantation is the optimum treatment for kidney failure in carefully selected patients. Technical surgical complications and second warm ischemic time (SWIT) increase the risk of delayed graft function (DGF) and subsequent short- and long-term graft outcomes including the need for post-transplant dialysis and graft failure. Intraoperative organ thermal regulation could reduce SWIT, minimizing surgical complications due to time pressure, and limiting graft ischemia-reperfusion injury.

METHODS

A novel ischemic-injury thermal protection jacket (iiPJ) was designed and fabricated in silicone composite and polyurethane (PU) elastomer prototypes. Both were compared with no thermal insulation as controls. Time to reach ischemic threshold (15°C) and thermal energy transfer were compared. A water bath model was used to examine the thermal protective properties of porcine kidneys, as a feasibility study prior to in vivo translation.

RESULTS

In both iterations of the iiPJ, the time taken to reach the warm ischemia threshold was 35.2 ± 1.4 minutes (silicone) and 38.4 ± 3.1 minutes (PU), compared with 17.2 ± 1.5 minutes for controls (n = 5, P < .001 for both comparisons). Thermal energy transfer was also found to be significantly less for both iiPJ variants compared with controls. There was no significant difference between the thermal performance of the 2 iiPJ variants.

CONCLUSION

Protection from SWIT by using a protective insulation jacket is feasible. With clinical translation, this novel strategy could facilitate more optimal surgical performance and reduce transplanted organ ischemia-reperfusion injury, in particular the SWIT, potentially affecting delayed graft function and long-term outcomes.

An Effective Cooling Device for Minimal-Incision Kidney Transplantation

BACKGROUND This study investigated the safety and efficacy of a new cooling device for use in minimal-incision kidney transplantation (MIKT). MATERIAL AND METHODS From June 2016 to December 2021, 9 patients underwent MIKT surgery in our hospitals using the new cooling device to maintain hypothermia. We recorded and analyzed information on the etiology, comorbid status, ongoing renal replacement assessment, BMI, HLA mismatching sites of donors and recipients, and perioperative and postoperative clinical data for recipients. RESULTS Kidney transplantation was successfully performed in all patients. The kidney surface temperature measurement results showed that the intraoperative renal anterior and posterior surface temperatures were stable at approximately 3.8±1.2°C and 5.2±1.3°C, respectively, during ice-water circulation. The mean operation time was 112±15 min, the artery anastomosis time was 16±6.0 min, and the vein anastomosis time was 14±4.5 min. All recipients recovered uneventfully. The patients were followed up for 6-30 months. Urinary and vascular complications were not found in any recipients. CONCLUSIONS The new cooling device can facilitate MIKT. It is safe and feasible to carry out MIKT using the new cooling device, which can reduce surgical trauma and improve the quality of vascular anastomosis with satisfactory cosmetic results.

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.

Robotic-assisted kidney transplantation in obese recipients compared to non-obese recipients: the European experience

PURPOSE

The main objective was to compare minor (Clavien I-II) and major (Clavien ≥ III) intra- and postoperative complications of living donor robotic assisted kidney transplantation (RAKT) in obese (≥ 30 kg/m² BMI), overweight (< 30/ ≥ 25 kg/m² BMI) and non-overweight recipients (< 25 kg/m² BMI).

METHODS

For the present retrospective study, we reviewed the multi-institutional ERUS-RAKT database to select consecutive living donor RAKT recipients. Functional outcomes, intra- and postoperative complications were compared between obese, overweight and non-overweight recipients.

RESULTS

169 living donor RAKTs were performed, by 10 surgeons, from July 2015 to September 2018 in the 8 European centers. 32 (18.9%) recipients were obese, 66 (39.1%) were overweight and 71 (42.0%) were non-overweight. Mean follow-up was 1.2 years. There were no major intra-operative complications in either study group. Conversion to open surgery occurred in 1 obese recipient, in 2 overweight recipients and no conversion occurred in non-overweight recipients (p = 0.3). Minor and major postoperative complications rates were similar in the 3 groups. At one-year of follow-up, median eGFR was similar in all groups [54 (45-60) versus 57 (46-70) versus 63 (49-78) ml/min/1.73 m² in obese, overweight and non-overweight recipient groups, respectively, p = 0.5]. Delayed graft function rate was similar in the 3 groups. Only the number of arteries was an independent predictive factor of suboptimal renal function at post-operative day 30 in the multivariate analysis.

CONCLUSION

RAKT in obese recipients is safe, compared to non-overweight recipients and yields very good function, when it performed at high-volume referral centers by highly trained transplant teams.

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.

Robotic kidney transplantation in the obese patient: 10-year experience from a single center

Despite increasing obesity rates in the dialysis population, obese kidney transplant candidates are still denied transplantation by many centers. We performed a single-center retrospective analysis of a robotic-assisted kidney transplant (RAKT) cohort from January 2009 to December 2018. A total of 239 patients were included in this analysis. The median BMI was 41.4 kg/m² , with the majority (53.1%) of patients being African American and 69.4% of organs sourced from living donors. The median surgery duration and warm ischemia times were 4.8 hours and 45 minutes respectively. Wound complications (mostly seromas and hematomas) occurred in 3.8% of patients, with 1 patient developing a surgical site infection (SSI). Seventeen (7.1%) graft failures, mostly due to acute rejection, were reported during follow-up. Patient survival was 98% and 95%, whereas graft survival was 98% and 93%, at 1 and 3 years respectively. Similar survival statistics were obtained from patients undergoing open transplant over the same time period from the UNOS database. In conclusion, RAKT can be safely performed in obese patients with minimal SSI risk, excellent graft function, and patient outcomes comparable to national data. RAKT could improve access to kidney transplantation in obese patients due to the low surgical complication rate.

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.

Dual Kidney Transplantation: A Single-Center Experience in Thailand

BACKGROUND

Dual kidney transplants (DKTs) from expanded criteria donors (ECDs) have been performed in our hospital since 2014. We needed to review our clinical outcome and update criteria to selected ECDs for DKTs.

MATERIALS AND METHODS

Between January 2014 and December 2016, 4 DKTs and 269 deceased donor kidney transplants were performed. The outcome of DKTs was reviewed. The literature was reviewed for surgical technique and indication for DKT.

RESULTS

Four DKTs were performed between 2014 and 2016. One-year graft survival rate was 100%. One patient developed delayed graft function. No morbidity or mortality occurred.

CONCLUSIONS

DKTs in our center were safe and had good outcome with optimized selected criteria. DKT can improve the rate of kidney transplant in a developing country.

A novel technique for en bloc kidney transplantation from infant donors with extremely low body weight by using the distal abdominal aorta as an outflow tract

Pediatric kidney donors remain underutilized due to the high risk of postoperative thrombosis. To address this problem, we developed a novel en bloc kidney transplantation technique using donor thoracic aorta and the distal abdominal aorta as inflow and outflow tracts, respectively. Briefly, eight kidneys from deceased infant donors under five months old and with low body weight (1.9-4.9 kg) were transplanted en bloc into four pediatric and four adult patients. The donor's common iliac artery or external iliac artery was anastomosed to the recipient's distal external iliac artery or inferior epigastric artery, respectively, as an outflow tract. Recipients received basiliximab or antithymocyte globulin as induction therapy followed by tacrolimus, mycophenolate mofetil, and prednisone but without prophylactic anticoagulation. Delayed graft function was observed in one patient but was reversed at 90 days posttransplant. Two patients had urine leakage, which was cured by conservative treatment. Two recipients developed lung infections that eventually cleared. No patients experienced posttransplant vascular thrombosis. After 1-1.5 years of follow-up, all patients are well and have normal serum creatinine levels. In conclusion, this novel en bloc kidney transplantation technique using a modified arterial inflow and outflow tract can prevent vascular thrombosis and provide adequate graft function.

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.

Renal Transplantation as a Platform for Teaching Residents Open Vascular Surgical Techniques: Effects on Early Graft Function

BACKGROUND

Over the past decade, increases in vascular fellowships and the use of endovascular technology have decreased the general surgery residents' exposure to open vascular surgery. We sought to elucidate whether renal transplant is a safe way to teach general surgery residents the essential tenants of vascular surgery without adversely affecting early patient outcomes.

METHODS

All solitary, adult deceased donor kidney transplants performed at the University of Wisconsin from 2011 through 2016 were identified and divided into a resident-assist (RA) and fellow-assist cohorts (FA). DGF, defined by the requirement of dialysis within 1 week of transplant, was the primary outcome. Early graft survival and postoperative complications were considered the secondary endpoints.

RESULTS

Of the 774 total cases, there were 228 (29.5%) in the RA cohort and 546 (70.5%) in the FA cohort. The RA and FA cohorts had comparable characteristics, except for a nonclinically significant difference in mean donor creatinine (0.96 vs 0.88mg/dL, p = 0.03). RA cases had a similar DGF rate compared to FA cases (25% vs 26%, p = 0.93). Additionally, there was no difference in 2-year graft survival (93.7% vs 95.5%, p = 0.38), nor the rates of graft thromboses (0.4% vs 0.7%, p = 0.65), incisional hernias (0.9% vs 1.8%, p = 0.35), and ureteral strictures (2.2% vs 1.6%, p = 0.55) between the 2 cohorts.

CONCLUSIONS

Resident involvement in renal transplantation has no effect on DGF and early allograft function. Though the procedural involvement of each resident in a case is variable, it seems to be a safe way to teach retroperitoneal vascular exposure and anastomotic techniques.

Factors Associated With Prolonged Warm Ischemia Time Among Deceased Donor Kidney Transplant Recipients

Supplemental digital content is available in the text.

Background

Prolonged warm ischemia time (WIT) is associated with graft failure and mortality, however less is known about factors associated with prolonged WIT.

Methods

In a cohort of United States deceased donor kidney transplant recipients identified using the Scientific Registry of Transplant Recipients (Jan 2005-Dec 2013), we identified factors associated with prolonged WIT (defined as ≥ 30 minutes versus 10-30 minutes) using hierarchical multilevel models adjusting for center effect, and WIT as a continuous variable using multiple linear regression of log-transformed data.

Results

Among 55 829 patients, potentially modifiable risk factors associated with prolonged WIT included increased recipient body mass index (BMI) (odds ratio [OR], 1.57; 95% confidence interval [CI], 1.44-1.72 for BMI > 35), right donor kidney (OR, 1.14; 95% CI, 1.08-1.19), and a prolonged cold ischemic time (OR, 1.23; 95% CI, 1.13-1.33 for cold ischemia time > 24 hours). Transplanting a right kidney into an obese recipient further prolonged WIT (OR, 1.75; 95% CI, 1.55-1.98; for BMI > 35), increasing overall WIT by 11.0%. There was no correlation between median WIT for a given center and annual center transplant rate (pairwise correlation coefficient, 0.0898).

Conclusions

In conclusion, several modifiable factors are associated with prolonged WIT and may represent strategies to improve WIT and subsequent posttransplant outcomes.

Robot-Assisted Transplant Surgery - Vision or Reality? A Comprehensive Review

Minimally invasive surgery is standard procedure for many operations. Further refinements include the introduction of robotic surgery which is still an emerging field especially in laparoscopic surgery. Since the successful introduction of the da Vinci Robotic Surgical System, the robotic approach in organ transplantation has become of great interest in both the live donor organ retrieval and the recipient operation. Robotic surgery for kidney, liver, and pancreas transplantation is feasible. Over 700 donor nephrectomies and 100 kidney transplantations have been performed already, and robotic surgery is standard in a small number of pioneer centers; however, larger series and most importantly randomized controlled trials for the highest evidence are needed. Longer warm ischemia time and higher costs limit these procedures at the moment.

Development and Feasibility of a Robotic Laparoscopic Clipping Tool for Wound Closure and Anastomosis

This paper reports the design, development, and initial evaluation of a robotic laparoscopic clipping tool for single manipulator wound closure and anastomosis (tubular reconnection). The tool deploys biodegradable clips and clasps with the goal of (i) integrating grasping and suturing into a single device for single hand or manipulator use, (ii) applying the equivalent of interrupted sutures without the need of managing suture thread, and (iii) allowing for full six degrees-of-freedom (DOFs) laparoscopic control when mounted on a robot arm. The specifications, workflow, and detailed design of the robotic laparoscopic tool and injection molded bio-absorbable T shaped clip and locking clasp are reported. The clipping tool integrates forceps to grab and stabilize tissue and a clip and clasp applier to approximate and fixate the tissue. A curved needle is advanced on a circular needle path and picks up and drags clips through tissue. The clip is then tightened through the tissue and a clasp is clamped around the clip, before the clip is released from the needle. Results of several bench test runs of the tool show: (a) repeatable circular needle drive, (b) successful pick-up and deployment of clips, (c) successful shear of the clip to release the clip from the needle, and (d) closure of clasp on clip with an average of 2.0 N holding force. These data indicate that the robotic laparoscopic clipping tool could be used for laparoscopic wound closure and anastomosis.

Intra-Abdominal Cooling System Limits Ischemia-Reperfusion Injury During Robot-Assisted Renal Transplantation

Robot-assisted kidney transplantation is feasible; however, concerns have been raised about possible increases in warm ischemia times. We describe a novel intra-abdominal cooling system to continuously cool the kidney during the procedure. Porcine kidneys were procured by standard open technique. Groups were as follows: Robotic renal transplantation with (n = 11) and without (n = 6) continuous intra-abdominal cooling and conventional open technique with intermittent 4°C saline cooling (n = 6). Renal cortex temperature, magnetic resonance imaging, and histology were analyzed. Robotic renal transplantation required a longer anastomosis time, either with or without the cooling system, compared to the open approach (70.4 ± 17.7 min and 74.0 ± 21.5 min vs. 48.7 ± 11.2 min, p-values < 0.05). The temperature was lower in the robotic group with cooling system compared to the open approach group (6.5 ± 3.1°C vs. 22.5 ± 6.5°C; p = 0.001) or compared to the robotic group without the cooling system (28.7 ± 3.3°C; p < 0.001). Magnetic resonance imaging parenchymal heterogeneities and histologic ischemia-reperfusion lesions were more severe in the robotic group without cooling than in the cooled (open and robotic) groups. Robot-assisted kidney transplantation prolongs the warm ischemia time of the donor kidney. We developed a novel intra-abdominal cooling system that suppresses the noncontrolled rewarming of donor kidneys during the transplant procedure and prevents ischemia-reperfusion injuries.

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.

Immediate breast reconstruction with omental flap for luminal breast cancer patients: Ten clinical case reports

RATIONALE

Luminal subtype breast cancer, accounting for 70 to 80% of all breast cancers, has been reported to be associated with good prognosis. However, for the patients with large mass or worse mass position, omental flap transplantation may provide a new option for breast reconstruction.

PATIENT CONCERNS

Ten patients (6 luminal B1, 2 luminal B2, 2 luminal A), were enrolled into the study, between January 23, 2015 and August 22, 2016. The mean age was 34.6 ± 6.96 (24-44) years old. Immunohistochemistry demonstrated that the tumor cells were positive for estrogen receptor and progestrone receptor.

DIAGNOSES

According to the clinicopathological features, diagnosis of breast cancer patients were made.

INTERVENTIONS

Breast-conserving surgery, laparoscopic greater omentum harvest and vascular anas-tomosis were carried out orderly. Postoperative operative results, cosmetic outcomes, complications, as well as blood supply were investigated for surgery evaluation. Reasonable chemotherapy and irradia-tion were adopted to patients according to the pathological condition.

OUTCOMES

We successfully accomplished breast reconstruction by omental flap transplantation, ex-cept one failed case because of the necrosis of omentum and changed to fat transplantation. The volumes and symmetry of breasts were all satisfied. The blood supply was detected to be fluent. Only one case of slight hematoma and another case of one distant metastasis were observed during fol-low-up period. No arm mordities or arm movement restriction occurred after surgery. Moreover, radia-tion therapy and chemotherapy had no clear effects on the reconstructed breast.

LESSONS

Immediate breast reconstruction surgery by transplanting omental flap for luminal breast cancer patients can be considered successful based on the excellent clinic outcome.

Factors Associated With Delayed Graft Function and Their Influence on Outcomes of Kidney Transplantation

BACKGROUND

One of the main postoperative complications of kidney transplant is delayed graft function (DGF), which means absence of graft function after transplant or the need for dialysis during the first week post procedure. The occurrence of DGF currently in our hospital is high and has been attributed to a combination of many factors. The aim of this study was to evaluate the factors associated to DGF and their influence in the outcome of kidney transplants.

METHODS

Historical cohort of 150 patients transplanted with live or deceased donor kidneys from 2011 to 2013.

RESULTS

DGF was associated to time in dialysis and the number of recipient pre-transplant transfusions, donors age, serum creatinine level, use of vasoactive drugs in the donor, distance from place of organ retrieval and transplant center, and duration of cold ischemia time. DGF influenced post-transplantation outcome in regard to length of stay in intensive care, length of hospital stay, acute rejection episodes, and higher creatinine levels at discharge. Patients and graft survival were shorter in the DGF group.

CONCLUSIONS

There are multiple factors related to DGF, the most important being those related to donors, and organ storage. The most important factor related to the recipient was the dialysis vintage. We did not find a correlation between DGF and HLA-compatibility. DGF consequences are important, including worse graft function and survival, as well as impact in recipient morbidity and mortality.

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 Impact of Anastomosis Time During Kidney Transplantation on Graft Loss: A Eurotransplant Cohort Study

Recent studies raised the concern that warm ischemia during completion of vascular anastomoses in kidney implantation harms the transplant, but its precise impact on outcome and its interaction with other risk factors remain to be established. We investigated the relationship between anastomosis time and graft survival at 5 years after transplantation in 13 964 recipients of deceased donor solitary kidney transplants in the Eurotransplant region. Anastomosis time was independently associated with graft loss after adjusting for other risk factors (adjusted hazard ratio [HR] 1.10 for every 10-min increase, 95% confidence interval [CI] 1.06-1.14; p < 0.0001), whereas it did not influence recipient survival (HR 1.00, 95% CI 0.97-1.02). Kidneys from donation after circulatory death (DCD) were less tolerant of prolonged anastomosis time than kidneys from donation after brain death (p = 0.02 for interaction). The additive effect of anastomosis time with donor warm ischemia time (WIT) explains this observation because DCD status was no longer associated with graft survival when adjusted for this summed WIT, and there was no interaction between DCD status and summed WIT. Time to create the vascular anastomoses in kidney transplantation is associated with inferior transplant outcome, especially in recipients of DCD kidneys.

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.

Extraction Time of Kidneys From Deceased Donors and Impact on Outcomes

Cold ischemia time (from flush to out-of-ice) and warm ischemia time (from out-of-ice to reperfusion) are known to impact delayed graft function (DGF) rates and long-term allograft survival following deceased donor kidney transplantation. We propose an additional ischemia time, extraction time, beginning with aortic cross-clamp and perfusion/cooling of the kidneys, and ending with removal of the kidneys and placement on ice on the backtable. During this time the kidneys rewarm, suffering an additional ischemic insult, which may impair transplant function. We measured extraction times of 576 kidneys recovered and transplanted locally between January 2006 and December 2008, then linked to Scientific Registry of Transplant Recipients (SRTR) data for outcomes. Extraction time ranged from 14 to 123 min, with a mean of 44.7 min. In SRTR-adjusted analyses, longer extraction time and DGF were statistically associated (odds ratio [OR] = 1.19 per 5 min beyond 60 min, 95% confidence interval [CI] 1.02-1.39, p = 0.03). Up to 60 min of extraction time, DGF incidence was 27.8%; by 120 min it doubled to nearly 60%. Although not statistically significant (OR = 1.19, 95% CI 0.96-1.49, p = 0.11), primary nonfunction rate also rose dramatically to nearly 20% by 120 min extraction time. Extraction time is a novel and important factor to consider when evaluating a deceased donor kidney offer and when strategizing personnel for kidney recovery.

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.