Pediatric renal transplantation-A UNOS database analysis of donor-recipient size mismatch.

BACKGROUND: We used the BSAi (Donor BSA/Recipient BSA) to assess whether transplanting a small or large kidney into a pediatric recipient relative to his/her size influences renal transplant outcomes. METHODS: We included 14 322 single-kidney transplants in pediatric recipients (0-17 years old) (01/2000-02/2020) from the United Network for Organ Sharing database. We divided cases into four BSAi groups (BSAi ≤ 1, 1 < BSAi ≤ 2, 2 < BSAi ≤ 3, BSAi > 3). RESULTS: There were no differences concerning delayed graft function (DGF) or primary non-function (PNF) rates, whether the grafts were from living or brain-dead donors. In both transplants coming from living donors and brain-dead donors, cases with BSAi > 3 and cases with 2 < BSAi ≤ 3 had similar graft survival (p = .13 for transplants from living donors, p = .413 for transplants from brain-dead donors), and both groups had longer graft survival than cases with 1 < BSAi ≤ 2 and cases with BSAi ≤ 1 (p < .001). The difference in 10-year graft survival rates between cases with BSAi > 3 and cases with BSAi ≤ 1 reached around 25% in both donor types. The better graft survival in transplants with BSAi > 2 was confirmed in multivariable analysis. CONCLUSIONS: There is no significant impact of donor-recipient size mismatch on DGF and PNF rates in pediatric renal transplants. However, graft survival is significantly improved when the donor's size is more than twice the pediatric recipient's size.

Endovascular salvage of thrombosed haemodialysis vascular access.

Background: Haemodialysis access thrombosis is associated with significant morbidity and access abandonment rates, for which endovascular salvage is a well described treatment option. This study aimed to evaluate the outcomes of endovascular salvage procedures of thrombosed vascular access circuits and identify factors influencing outcomes. Patients and methods: Retrospective review of 328 consecutive procedures performed over 10 years at our institution between January 2010 and December 2019. Patient demographics, access circuit characteristics, procedure details and outcome data were collected. Kaplan-Meier survival curves were used to estimate patency rates and Cox multivariate regression analysis to identify factors affecting outcomes. Results: Technical and clinical success rates were 87.8% and 75.9% respectively. The primary, primary assisted and secondary patency rates at 6 months were 42.2%, 46.7% and 59.1%; and at 12 months were 23.4%, 28.3% and 41.8% respectively. Median access circuit survival was 9.2 months. Major complication rate was 5.2% including 3 procedure-related deaths. Native AVF, lower time from thrombosis to intervention and pharmacomechanical thrombectomy using AngioJetTM predicted positive outcomes. Previous thrombectomy within 3 months and residual thrombus at completion were associated with poorer outcomes. Age and hypertension predicted higher complication rates. Conclusions: This is one of the largest single center series of endovascular salvage of thrombosed haemodialysis access and demonstrates that endovascular treatment is effective and provides durable access circuit survival. Careful patient screening is essential to optimize outcomes.

Crisis Containment: Tools for Harm Mitigation in Surgery.

BACKGROUND: Surgical crises represent unrecognized opportunities for improving patient safety and adding value in healthcare. The first step in a crisis response is to contain and mitigate harm. While the principles of damage control are well established in surgery, methods of containing harm on broader clinical and organizational levels are not clearly defined. STUDY DESIGN: A multimethods qualitative study identified crisis containment strategies and tools in commercial aviation. These were translated and clinically adapted in 3 stages: semi-structured observational fieldwork with commercial airlines, interviews with senior pilots, and focus groups with both healthcare and aviation safety experts. Thematic analysis and expert consensus methods were used to derive a framework for crisis containment. RESULTS: Fieldwork with 2 commercial airlines identified 2 crisis containment concepts: the detrimental impact of surprising or startling events on operator performance; and the use of prioritization tools to take basic but critical actions (Aviate, Navigate and Communicate model). Twenty-two experts in aviation and healthcare practice informed the topic of crisis containment in 17 interviews and 3 focus groups. Three strategies were identified and used to form a crisis containment algorithm: 1. Manage the operators' startle response to facilitate meaningful mitigating actions (STOP tool); 2. Take priority actions to secure core functions. These included managing patients' physiologic shock, optimizing environmental risks, and mobilizing resources (Perfuse, Move and Communicate tool); 3. Deploy well-rehearsed drills targeting case-specific harms or errors (Memory Actions). This model requires validation in clinical practice. CONCLUSIONS: Crisis containment can be achieved by controlling operators' startle response, applying prioritization tools, and deploying drills against specific failures. The application of this model may extend to healthcare areas outside surgery.

Avoid, Trap, and Mitigate: Development of an Evidence-Based Crisis Management Framework in Surgery.

BACKGROUND: Increasingly, surgeons are adopting broader roles in emergency response, on both clinical and executive levels. These have highlighted the need to develop healthcare-specific crisis management systems. Cross-professional research between safety-critical industries is a valuable method for learning crisis control. Commercial aviation, in particular, has been used to drive innovation in surgical safety. This study aimed to identify, adapt, and operationalize a surgical crisis management framework based on current practice in commercial aviation. STUDY DESIGN: A multimethod qualitative study interrogated safety experts in commercial aviation and healthcare. Stage I used immersive observational fieldwork in commercial aviation practice. Stage II performed semi-structured interviews with senior airline pilots. "Snowball" sampling targeted professional networks, recruiting 17 pilots from 4 airlines. Thematic analysis was used to derive a model of crisis management. Stage III undertook 3 focus groups with 5 pilots and 5 healthcare safety specialists. Expert consensus methods were used to adapt the model to clinical practice. RESULTS: Interview data provided 2,698 verbatim quotes on crisis management from aviation experts with a combined flying experience of 188,000 hours. Aviation crisis management was structured in 3 phases: avoid, trap, and mitigate. Adapted to clinical practice, these translated to crisis preparedness, recovery, and containment interventions. Additionally, the study identified 7 types of implementation tools and 9 crisis management skills that could be used to operationalize this framework in surgical practice. CONCLUSIONS: Surgical crisis management can follow the avoid, trap, and mitigate framework used in commercial aviation. Implementation relies on the combined use of crisis skills and performance tools. Crisis management should be delivered as part of a systems-based approach that relies on well-integrated failure management models. Simulation and in-situ validation of this framework is needed.

The implications of donor-recipient size mismatch in renal transplantation.

INTRODUCTION: Transplanting kidneys small for recipient's size results in inferior graft function. Body surface area (BSA) is related to kidney size. We used the BSA index (BSAi) (Donor BSA/Recipient BSA) to assess whether the renal graft size is sufficient for the recipient. METHODS: We included 26,223 adult single kidney transplants (01/01/2007-31/12/2019) from the UK Transplant Registry. We divided renal transplants into groups: BSAi ≤ 0.75, 0.75 < BSA ≤ 1, 1 < BSAi ≤ 1.25, BSAi > 1.25. We compared delayed graft function rates, primary non-function rates and graft survival among them. (Reference category: BSAi ≤ 0.75). RESULTS: Cases with BSAi ≤ 0.75 had the highest delayed graft function rates in living-donor renal transplants (11.1%) (0.75 < BSAi ≤ 1: OR = 0.59, 95% CI = 0.32-1.1, p = 0.095, 1 < BSAi ≤ 1.25: OR = 0.46, 95% CI = 0.23-0.89, p = 0.022, BSAi > 1.25: OR = 0.32, 95% CI = 0.13-0.77, p = 0.011) and in renal transplants from donors after brain death (26.2%) (0.75 < BSAi ≤ 1: OR = 0.72, 95% CI = 0.55-0.96, p = 0.024, 1 < BSAi ≤ 1.25: OR = 0.62, 95% CI = 0.47-0.83, p = 0.001, BSAi > 1.25: OR = 0.65, 95% CI = 0.47-0.9, p = 0.01). There were no significant differences in renal transplants from donors after circulatory death regarding delayed graft function rates (~ 40% in all groups). Graft survival was similar among BSAi groups in renal transplants from living donors and donors after brain death. Renal transplants from donors after circulatory death with BSAi ≤ 0.75 had the shortest graft survival (0.75 < BSAi ≤ 1: HR = 0.55, 95% CI = 0.41-0.74, p < 0.001, 1 < BSAi ≤ 1.25: HR = 0.48, 95% CI = 0.35-0.66, p < 0.001, BSAi > 1.25: HR = 0.45, 95% CI = 0.31-0.66, p < 0.001). Ten-year graft survival rate was 58.4% for renal transplants from donors after circulatory death with BSAi ≤ 0.75. CONCLUSIONS: Delayed graft function risk is higher in renal transplants with BSAi ≤ 0.75 coming from living donors and donors after brain death. Graft survival is greatly reduced in renal transplants from donors after circulatory death with BSAi ≤ 0.75.

Comparison between bovine carotid artery graft and polytetrafluoroethylene graft for haemodialysis vascular access: A systematic review and meta-analysis.

BACKGROUND: There is a renewed interest in using bovine carotid artery grafts for haemodialysis vascular access after recent advances in conduit manufacturing and endovascular management of access-related complications. Our aim was to summarize the results of the recent studies comparing bovine carotid artery grafts with polytetrafluoroethylene grafts as vascular access for haemodialysis. METHODS: A systematic review was conducted for original articles comparing bovine carotid artery with polytetrafluoroethylene grafts for haemodialysis vascular access published between January 2000 and December 2019 searching the databases of Medline, Scopus, Google Scholar, ClinicalTrials.gov and the Cochrane Central Register of Controlled Trials. RESULTS: Four studies were included (one prospective randomized controlled trial and three retrospective studies) with 676 patients in total (bovine carotid artery: 395, polytetrafluoroethylene: 281). There was lower graft infection rate per patient-year in bovine carotid artery grafts (mean difference: -0.03, p < 0.0001). Bovine carotid artery grafts required fewer interventions per patient-year to maintain or restore patency (mean difference: -0.81, p = 0.002). No significant difference was detected regarding pseudoaneurysm formation (p = 0.24), steal syndrome (p = 0.11) or patency rates (primary: 1 year: p = 0.15, 2 years: p = 0.69; primary assisted: 1 year: p = 0.18, 2 years: p = 0.54; secondary: 1 year: p = 0.22, 2 years: p = 0.17). CONCLUSION: Bovine carotid artery and polytetrafluoroethylene grafts have similar short-term and long-term outcomes, with a possible advantage of bovine carotid artery grafts concerning graft infections and number of required interventions. Thus, bovine carotid artery grafts can be a useful alternative modality for haemodialysis vascular access.

Hypoperfusion warm ischaemia time in renal transplants from donors after circulatory death.

BACKGROUND: The donor hypoperfusion phase before asystole in renal transplants from donors after circulatory death (DCD) has been considered responsible for worse outcomes than those from donors after brain death (DBD). METHODS: We included 10 309 adult renal transplants (7128 DBD and 3181 DCD; 1 January 2010-31 December 2016) from the UK Transplant Registry. We divided DCD renal transplants into groups according to hypoperfusion warm ischaemia time (HWIT). We compared delayed graft function (DGF) rates, primary non-function (PNF) rates and graft survival among them using DBD renal transplants as a reference. RESULTS: The DGF rate was 21.7% for DBD cases, but ∼40% for DCD cases with HWIT ≤30 min (0-10 min: 42.1%, 11-20 min: 43%, 21-30 min: 38.4%) and 60% for DCD cases with HWIT >30 min (P < 0.001). All DCD groups showed higher DGF risk than DBD renal transplants in multivariable analysis {0-10 min: odds ratio [OR] 2.686 [95% confidence interval (CI) 2.352-3.068]; 11-20 min: OR 2.531 [95% CI 2.003-3.198]; 21-30 min: OR 1.764 [95% CI 1.017-3.059]; >30 min: OR 5.814 [95% CI 2.798-12.081]}. The highest risk for DGF in DCD renal transplants with HWIT >30 min was confirmed by multivariable analysis [versus DBD: OR 5.814 (95% CI 2.798-12.081) versus DCD: 0-10 min: OR 2.165 (95% CI 1.038-4.505); 11-20 min: OR 2.299 (95% CI 1.075-4.902); 21-30 min: OR 3.3 (95% CI 1.33-8.197)]. No significant differences were detected regarding PNF rates (P = 0.713) or graft survival (P = 0.757), which was confirmed by multivariable analysis. CONCLUSIONS: HWIT >30 min increases the risk for DGF greatly, but without affecting PNF or graft survival.

Biological Mesh Repair of a Large Incisional Hernia Containing a Kidney Transplant in the Presence of Inflammation.

The incidence of incisional hernia after kidney transplantation varies between 1.1% and 3.8%. These are usually repaired electively using polypropylene mesh. We present here a case where a patient presented as an emergency, with a large painful incisional hernia over his kidney transplant, and evidence of local erythema and systemic inflammation. As this could have represented either infection or rejection, the patient was started on antibiotics and subsequently underwent graft nephrectomy and hernia repair using a biological (porcine-derived) acellular dermal matrix, Strattice™, with a satisfactory outcome. In addition, histology showed evidence of allograft rejection. This is the first reported case of an incisional hernia containing a rejecting kidney allograft, managed with nephrectomy and biological mesh repair.

UK renal transplant outcomes in low and high BMI recipients: the need for a national policy.

INTRODUCTION: We assessed the effect of recipient body mass index (BMI) on the outcomes of renal transplantation and the management of obese patients with end-stage renal disease across the UK. METHODS: We analyzed data of 25539 adult renal transplants (2007-2016) from the UK Transplant Registry. Patients were divided in BMI groups [underweight: < 18.5, normal: 18.5-24.9 (reference group), overweight: 25-29.9, class I obese: 30-34.9, class II/III obese: ≥ 35]. We also conducted a national survey of all UK renal transplant centers on the influence of BMI on decisions regarding management of renal transplant candidates. RESULTS: BMI ≥ 25 was an independent risk factor for delayed graft function and primary non-function (p ≤ 0.001). Underweight (p = 0.001), class I obese (p = 0.017) and class II/III obese recipients (p < 0.001) had poorer graft survival, however, 5- and 10-year graft survival rates were good. Patient survival was shorter for underweight recipients (p < 0.001) and longer for overweight (p = 0.028) and class I obese recipients (p = 0.013). The national survey revealed significant variability among transplant centers in BMI threshold for listing patients on transplant waiting list and limited support with conservative or surgical procedures for weight control. CONCLUSIONS: Obesity alone should not be a barrier for renal transplantation. A national strategy is required to give all patients equal chances in transplantation.

Comparison Between Robotic and Laparoscopic or Open Anastomoses: A Systematic Review and Meta-Analysis.

INTRODUCTION: Robotic surgery has been increasingly used in fashioning various surgical anastomoses. Our aim was to collect and analyze outcomes related to anastomoses performed using a robotic approach and compare them with those done using laparoscopic or open approaches through meta-analysis. METHODS: A systematic review was conducted for articles comparing robotic with laparoscopic and/or open operations (colectomy, low anterior resection, gastrectomy, Roux-en-Y gastric bypass (RYGB), pancreaticoduodenectomy, radical cystectomy, pyeloplasty, radical prostatectomy, renal transplant) published up to June 2019 searching Medline, Scopus, Google Scholar, Clinical Trials and the Cochrane Central Register of Controlled Trials. Studies containing information about outcomes related to hand-sewn anastomoses were included for meta-analysis. Studies with stapled anastomoses or without relevant information about the anastomotic technique were excluded. We also excluded studies in which the anastomoses were performed extracorporeally in laparoscopic or robotic operations. RESULTS: We included 83 studies referring to the aforementioned operations (4 randomized controlled and 79 non-randomized, 10 prospective and 69 retrospective) apart from colectomy and low anterior resection. Anastomoses done using robotic instruments provided similar results to those done using laparoscopic or open approach in regards to anastomotic leak or stricture. However, there were lower rates of stenosis in robotic than in laparoscopic RYGB (p=0.01) and in robotic than in open radical prostatectomy (p<0.00001). Moreover, all anastomoses needed more time to be performed using the robotic rather than the open approach in renal transplant (p≤0.001). CONCLUSION: Robotic anastomoses provide equal outcomes with laparoscopic and open ones in most operations, with a few notable exceptions.

Utilisation of small paediatric donor kidneys for transplantation.

With the increasing need for kidney transplantation in the paediatric population and changing donor demographics, children without a living donor option will potentially be offered an adult deceased donor transplant of marginal quality. Given the importance of long-term graft survival for paediatric recipients, consideration is now being given to kidneys from small paediatric donors (SPDs). There exist a lack of consensus and a reluctance amongst some centres in transplanting SPDs due to high surgical complication rates, graft loss and concerns regarding low nephron mass and long-term function. The aim of this review is to examine and present the evidence base regarding the transplantation of these organs. The literature in both the paediatric and adult renal transplant fields, as well as recent relevant conference proceedings, is reviewed. We discuss the surgical techniques, long-term graft function and rates of complications following transplantation of SPDs. We compare graft survival of SPDs to adult deceased donors and consider the use of small paediatric donors after circulatory death (DCD) organs. In conclusion, evidence is presented that may refute historically held paradigms regarding the transplantation of SPDs in paediatric recipients, thereby potentially allowing significant expansion of the donor pool.

Outcomes in Third and Fourth Kidney Transplants Based on the Type of Donor.

BACKGROUND: An increasing number of patients are requiring multiple retransplants. We assessed outcomes of third and fourth kidney transplants, to aid decision making on the most suitable donor type. METHODS: Data were collected retrospectively for 2561 transplants, including 69 third and 8 fourth, performed from 2000 to 2017. Demographics and outcomes for the combined third/fourth group were compared to first and second transplants. Within the third/fourth kidney transplant group, comparisons were made between deceased donors (n = 39), live donor HLA-compatible (n = 23) and -incompatible (n = 13) transplants, as well as between standard (n = 25) and extended-criteria (n = 14) deceased donor transplants. RESULTS: Patient survival did not differ significantly by transplant number (P = 0.532), whereas death-censored graft survival declined progressively, from 89% at 5 years in first, 85% in second and 74% in the third/fourth transplant group (P < 0.001). Within the combined third/fourth transplant subgroup, 5-year graft survival was found to be 100% in recipients of HLA-compatible live donors, compared to 75% in deceased donors and 53% in HLA-incompatible live donors, although this difference did not reach statistical significance (P = 0.083). No significant difference in patient survival (P = 0.356) or complication rates (P = 0.757) were detected between these groups. For recipients of deceased donors in the third/fourth transplant group, there were no significant differences between standard versus extended-criteria donors for any of the outcomes considered. CONCLUSIONS: Despite variable functional outcomes, third and fourth kidney transplant recipients experience comparable patient survival rates to first and second transplants, regardless of the donor type. In selected patients, HLA-incompatible live donors and extended-criteria deceased donors should be considered.

A novel 3D-printed hybrid simulation model for robotic-assisted kidney transplantation (RAKT).

Robotic-assisted kidney transplantation (RAKT) offers key benefits for patients that have been demonstrated in several studies. A barrier to the wider uptake of RAKT is surgical skill acquisition. This is exacerbated by the challenges of modern surgery with reduced surgical training time, patient safety concerns and financial pressures. Simulation is a well-established method of developing surgical skill in a safe and controlled environment away from the patient. We have developed a 3D printed simulation model for the key step of the kidney transplant operation which is the vascular anastomosis. The model is anatomically accurate, based on the CT scans of patients and it incorporates deceased donor vascular tissue. Crucially, it was developed to be used in the robotic operating theatre with the operating robot to enhance its fidelity. It is portable and relatively inexpensive when compared with other forms of simulation such as virtual reality or animal lab training. It thus has the potential of being more accessible as a training tool for the safe acquisition of RAKT specific skills. We demonstrate this model here.

A Re-evaluation of Discarded Deceased Donor Kidneys in the UK: Are Usable Organs Still Being Discarded?

BACKGROUND: A significant proportion of procured deceased donor kidneys are subsequently discarded. The UK Kidney Fast-Track Scheme (KFTS) was introduced in 2012, enabling kidneys at risk of discard to be simultaneously offered to participating centers. We undertook an analysis of discarded kidneys to determine if unnecessary organ discard was still occurring since the KFTS was introduced. METHODS: Between April and June 2015, senior surgeons independently inspected 31 consecutive discarded kidneys from throughout the United Kingdom. All kidneys were biopsied. Organs were categorized as usable, possibly usable pending histology, or not usable for implantation. After histology reports were available, final assessments of usability were made. RESULTS: There were 19 donors (6 donations after brain death, 13 donations after circulatory death), with a median (range) donor age of 67 (29-83) years and Kidney Donor Profile Index of 93 (19-100). Reasons for discard were variable. Only 3 discarded kidneys had not entered the KFTS. After initial assessment postdiscard, 11 kidneys were assessed as usable, with 9 kidneys thought to be possibly usable. Consideration of histological data reduced the number of kidneys thought usable to 10 (10/31; 32%). CONCLUSIONS: The KFTS scheme is successfully identifying organs at high risk of discard, though potentially transplantable organs are still being discarded. Analyses of discarded organs are essential to identify barriers to organ utilization and develop strategies to reduce unnecessary discard.

Successful endovascular treatment of transplant intrarenal artery stenosis in renal transplant recipients: Two case reports.

Transplant renal artery stenosis (TRAS) is a relatively rare complication after renal transplantation. The site of the surgical anastomosis is most commonly involved, but sites both proximal and distal to the anastomosis may occur, as well. Angioplasty is the gold standard for the treatment of the stenosis, especially for intrarenal lesions. We report two cases of intrarenal TRAS and successful management with angioplasty without stent placement. Both patients were male, 44 and 55 years old respectively, and they presented with elevated blood pressure or serum creatinine within three months after transplantation. Subsequently, they have undergone angioplasty balloon dilatation with normalization of blood pressure and serum creatinine returning to baseline level. Percutaneous transluminal balloon renal angioplasty is a safe and effective method for the treatment of the intrarenal TRAS.

Mycophenolate mofetil and sirolimus in hepatocyte transplantation in an experimental model of toxic acute liver failure.

INTRODUCTION: Hepatocyte transplantation is proposed as a solution for liver failure. The allotransplantation of hepatocytes has been studied extensively, however, graft rejection remains a major problem. The aim of the present study was to evaluate the immunosuppressive activity of mycophenolate mofetil (MMF), sirolimus, and their combination in an experimental model of hepatocyte allotransplantation in rats with acute liver failure. MATERIALS AND METHODS: Five male Wistar rats were used as hepatocyte donors and 60 male Lewis rats as recipients. The recipients were divided into five groups of 12 animals each. Group 1: no treatment. Group 2: cyclosporine. Group 3: sirolimus. Group 4: MMF. Group 5: MMF and sirolimus. All surviving animals were preserved for 15 days. For the induction of acute liver failure the recipients were injected with N-dimethyl-nitrosamine 24 hr before transplantation. The isolated hepatocytes were transplanted intrasplenically. RESULTS: Analysis of the results showed a statistically significant prolongation of animal survival for groups 3, 4, and 5. More animals in group 5 survived than those in groups 3 and 4, although the difference was not statistically significant. Transplant hepatocyte survival was significantly better in groups 3, 4, and 5. Hepatocytes transplanted in the spleen of animals of group 5 showed better survival compared with those of groups 3 and 4. CONCLUSION: Use of MMF and sirolimus, as monotherapy or in combination, is both effective and safe as immunosuppressive treatment in hepatocyte transplantation, as was proven in this experimental protocol.