Pancreas Transplantation in Black, Asian and Minority Ethnic Patients-Single Centre Experience in the UK.

Ethnic disparities in the outcomes after simultaneous pancreas kidney (SPK) transplantation still exist. The influence of ethnicity on the outcomes of pancreas transplantation in the UK has not been reported and hence we aimed to investigate our cohort. A retrospective analysis of all pancreas transplant recipients (n = 171; Caucasians = 118/Black Asian Ethnic Minorities, BAME = 53) from 2006 to 2020 was done. The median follow-up was 80 months. Patient & pancreas graft survival, rejection rate, steroid free maintenance rate, HbA1c, weight gain, and the incidence of secondary diabetic complications post-transplant were compared between the groups. p < 0.003 was considered significant (corrected for multiple hypothesis testing). Immunosuppression consisted of alemtuzumab induction and steroid free maintenance with tacrolimus and mycophenolate mofetil. Pancreas graft & patient survival were equivalent in both the groups. BAME recipients had a higher prevalence of type-2 diabetes mellitus pre-transplant (BAME = 30.19% vs. Caucasians = 0.85%, p < 0.0001), and waited for a similar time to transplantation once waitlisted, although pre-emptive SPK transplantation rate was higher for Caucasian recipients (Caucasians = 78.5% vs. BAME = 0.85%, p < 0.0001). Despite equivalent rejections & steroid usage, BAME recipients gained more weight (BAME = 7.7% vs. Caucasians = 1.8%, p = 0.001), but had similar HbA1c (functioning grafts) at 3-,12-, 36-, and 60-months post-transplant.

Endovascular Thrombectomy and Lysis for Acute Renal Vein Thrombosis: Indications, Technical Aspects, Outcome, and Disease Etiology.

PURPOSE: To report a rare case of acute renal vein thrombosis (RVT) that was treated with endovascular thrombectomy and lysis, and discuss potential etiology and indications for catheter-directed management. CASE REPORT: A 21-year-old female athlete presented with sudden pain in her left flank and vomiting. A 3-phase computed tomography (CT) angiogram identified total occlusion of the left renal vein with no excretion from the swollen tender left kidney. Catheter-directed thrombolysis and thrombectomy were initiated 24 hours after onset of symptoms. Complete resolution of the RVT with normalized renal function was achieved. Post-operative Doppler ultrasound scan confirmed normal renal resistance and flow in the renal vein. The patient was discharged on Apixaban and remains well at 6 months. Combined hormonal contraception via an intra-vaginal ring and raised Factor VIII activity were the only identified risk factors. CONCLUSION: Acute complete RVT with impaired kidney function is rare. Combined hormonal contraception and increased Factor VIII activity were potential risk factors. Endovascular thrombectomy and lysis restored renal perfusion and function, and can be used effectively in the management of fit patients with acutely compromised kidney function from total renal vein obstruction.

Fast-Track Cardiac Anesthesia Aids in the Early Diagnosis of Lower Extremity Compartment Syndrome: A Case Report.

A 21-year-old otherwise healthy male with severe asymptomatic mitral regurgitation underwent a mitral valve repair via right thoracotomy and right femoral cannulation for cardiopulmonary bypass. Due to his age and health status, the anesthetic was planned to facilitate early extubation. Immediately on arrival to the intensive care unit, the patient complained of severe right calf pain with decreased sensation of the plantar foot. He was diagnosed with compartment syndrome and was taken back to the operating room for emergent 4-compartment fasciotomy. The fast-track anesthetic allowed for early diagnosis and treatment and prevented a likely catastrophic outcome.

Carpal tunnel syndrome in patients with arteriovenous fistula for haemodialysis: A narrative review of the current literature.

The ideal choice of vascular access in patients requiring haemodialysis is an arteriovenous fistula. However, an important often under-reported complication encountered at follow-up is symptoms of tingling or numbness in the hand. This may represent carpal tunnel syndrome, impairment of the median nerve as it traverses through the carpal tunnel at the wrist by focal compression of this nerve. Contributory factors in the presence of an arteriovenous fistula may include venous hypertension and varying steal syndrome phenomena provoking micro-ischaemia. Studies that investigated the evolution of carpal tunnel syndrome in haemodialysis patients with an arteriovenous fistula revealed that the frequency of carpal tunnel syndrome associated with an arteriovenous fistula on haemodialysis ranged from 10.4% to 42.6%. An association between duration of haemodialysis with arteriovenous fistula and carpal tunnel syndrome development was also observed. Surgical release of carpal tunnel provided complete relief of paraesthesia in all treated patients in the examined, demonstrating an alleviation of symptoms and improved function of hand and quality of life in patients with an arteriovenous fistula. However, the aetiology and risk factors for development of carpal tunnel syndrome remain unclear and further studies should attempt to elucidate the pathophysiology of this occurrence in the presence of arteriovenous fistulas.

Feasibility of a 3 mm arteriotomy for brachiocephalic fistula formation.

BACKGROUND: The arteriovenous fistula is the modality of choice for long-term haemodialysis access. We describe the feasibility of routinely fashioning a brachiocephalic fistula utilising a 3 mm long arteriotomy in an attempt to reduce the incidence of symptomatic steal syndrome yet while maintaining satisfactory clinical outcomes. METHODS: All patients who underwent brachiocephalic fistula formation using a routine 3 mm long arteriotomy within Hammersmith Hospital between January 2017 and March 2018 were included. Primary outcomes included primary failure, failure of maturation, secondary patency and steal syndrome. RESULTS: Sixty-eight brachiocephalic arteriovenous fistula were fashioned utilising a 3 mm long arteriotomy during the study period. Mean age was 60.5 years with 59% having a history of diabetes mellitus. Mean followup was 368 days. Primary failure occurred in 10 (14.7%) patients. Cannulation was achieved in 67.3% of remaining fistula within 3-months, rising to 87.3% by 6-months. Primary patency at 6 and 12 months was 76% and 69%, respectively. Secondary patency at 6 and 12 months was 94% and 91%, respectively. Dialysis access steal syndrome was clinically apparent in three (4.4%) patients with all cases being managed conservatively. CONCLUSION: A 3 mm long arteriotomy may be routinely utilised for brachiocephalic fistula creation in an attempt to limit the incidence of steal syndrome yet while maintaining clinical patency outcomes.

Anticoagulation in simultaneous pancreas kidney transplantation - On what basis?

BACKGROUND: Despite technical refinements, early pancreas graft loss due to thrombosis continues to occur. Conventional coagulation tests (CCT) do not detect hypercoagulability and hence the hypercoagulable state due to diabetes is left untreated. Thromboelastogram (TEG) is an in-vitro diagnostic test which is used in liver transplantation, and in various intensive care settings to guide anticoagulation. TEG is better than CCT because it is dynamic and provides a global hemostatic profile including fibrinolysis. AIM: To compare the outcomes between TEG and CCT (prothrombin time, activated partial thromboplastin time and international normalized ratio) directed anticoagulation in simultaneous pancreas and kidney (SPK) transplant recipients. METHODS: A single center retrospective analysis comparing the outcomes between TEG and CCT-directed anticoagulation in SPK recipients, who were matched for donor age and graft type (donors after brainstem death and donors after circulatory death). Anticoagulation consisted of intravenous (IV) heparin titrated up to a maximum of 500 IU/h based on CCT in conjunction with various clinical parameters or directed by TEG results. Graft loss due to thrombosis, anticoagulation related bleeding, radiological incidence of partial thrombi in the pancreas graft, thrombus resolution rate after anticoagulation dose escalation, length of the hospital stays and, 1-year pancreas and kidney graft survival between the two groups were compared. RESULTS: Seventeen patients who received TEG-directed anticoagulation were compared against 51 contemporaneous SPK recipients (ratio of 1: 3) who were anticoagulated based on CCT. No graft losses occurred in the TEG group, whereas 11 grafts (7 pancreases and 4 kidneys) were lost due to thrombosis in the CCT group (P = 0.06, Fisher's exact test). The overall incidence of anticoagulation related bleeding (hematoma/ gastrointestinal bleeding/ hematuria/ nose bleeding/ re-exploration for bleeding/ post-operative blood transfusion) was 17.65% in the TEG group and 45.10% in the CCT group (P = 0.05, Fisher's exact test). The incidence of radiologically confirmed partial thrombus in pancreas allograft was 41.18% in the TEG and 25.50% in the CCT group (P = 0.23, Fisher's exact test). All recipients with partial thrombi detected in computed tomography (CT) scan had an anticoagulation dose escalation. The thrombus resolution rates in subsequent scan were 85.71% and 63.64% in the TEG group vs the CCT group (P = 0.59, Fisher's exact test). The TEG group had reduced blood product usage {10 packed red blood cell (PRBC) and 2 fresh frozen plasma (FFP)} compared to the CCT group (71 PRBC/ 10 FFP/ 2 cryoprecipitate and 2 platelets). The proportion of patients requiring transfusion in the TEG group was 17.65% vs 39.25% in the CCT group (P = 0.14, Fisher's exact test). The median length of hospital stay was 18 days in the TEG group vs 31 days in the CCT group (P = 0.03, Mann Whitney test). The 1-year pancreas graft survival was 100% in the TEG group vs 82.35% in the CCT group (P = 0.07, log rank test) and, the 1-year kidney graft survival was 100% in the TEG group vs 92.15% in the CCT group (P = 0.23, log tank test). CONCLUSION: TEG is a promising tool in guiding judicious use of anticoagulation with concomitant prevention of graft loss due to thrombosis, and reduces the length of hospital stay.

Cold Pulsatile Machine Perfusion versus Static Cold Storage in Kidney Transplantation: A Single Centre Experience.

INTRODUCTION: We present our experience with hypothermic machine perfusion (HMP) versus cold storage (CS) in relation to kidney transplant outcomes. METHODS: Retrospective analysis of 33 consecutive HMP kidney transplant outcomes matched with those of 33 cold stored: delayed graft function (DGF), length of hospital stay (LOS), estimated glomerular filtration rate (eGFR), and patient and graft survival were compared. Renal Resistive Indexes (RIs) during HMP in relation to DGF were also analysed. RESULTS: In the HMP group, mean HMP time was 5.7 ± 3.9 hours with a mean cold ischaemic time (CIT) of 15 ± 5.6 versus 15.1 ± 5.3 hours in the CS group. DGF was lower in the HMP group (p=0.041), and donation after Circulatory Death (DCD) was a predictor for DGF (p<0.01). HMP decreased DGF in DCD grafts (p=0.036). Patient and graft survival were similar, but eGFR at 365 days was higher in the HMP cohort (p<0.001). RIs decreased during HMP (p<0.01); 2-hours RI ≥ 0.45 mmHg/mL/min predicted DGF in DCD kidneys (75% sensitivity, 80% specificity; area under the curve 0.78); 2-hours RI ≥ 0.2 mmHg/ml/min predicted DGF in DBD grafts (sensitivity 100%, specificity 91%; area under the curve 0.87). CONCLUSION: HMP decreased DGF compared to CS, offering viability assessment pretransplant and improving one-year renal function of the grafts.

Heterogeneity in the nonplanarity and arterial curvature of arteriovenous fistulas in vivo.

OBJECTIVE: Native arteriovenous fistulas (AVFs) for hemodialysis are susceptible to nonmaturation. Adverse features of local blood flow have been implicated in the formation of perianastomotic neointimal hyperplasia that may underpin nonmaturation. Whereas computational fluid dynamic simulations of idealized models highlight the importance of geometry on fluid and vessel wall interactions, little is known in vivo about AVF geometry and its role in adverse clinical outcomes. This study set out to examine the three-dimensional geometry of native AVFs and the geometric correlates of AVF failure. METHODS: As part of an observational study between 2013 and 2016, patients underwent creation of an upper limb AVF according to current surgical best practice. Phase-contrast magnetic resonance imaging was performed on the day of surgery to obtain luminal geometry along with ultrasound measurements of flow. Magnetic resonance imaging data sets were segmented and reconstructed for quantitative and qualitative analysis of local geometry. Clinical maturation was evaluated at 6 weeks. RESULTS: There were 60 patients who were successfully imaged on the day of surgery. Radiocephalic (n = 17), brachiocephalic (n = 40), and brachiobasilic (n = 3) fistulas were included in the study. Centerlines extracted from segmented vessel lumen exhibited significant heterogeneity in arterial nonplanarity and curvature. Furthermore, these features are more marked in brachiocephalic than in radiocephalic fistulas. Across the cohort, the projected bifurcation angle was 73 ± 16 degrees (mean ± standard deviation). Geometry was preserved at 2 weeks in 20 patients who underwent repeated imaging. A greater degree of arterial nonplanarity (log odds ratio [logOR], 0.95 per 0.1/vessel diameter; 95% confidence interval [CI], 0.22-1.90; P = .03) and a larger bifurcation angle (logOR, 0.05 per degree; 95% CI, 0.01-0.09; P = .02) are associated with a greater rate of maturation, as is fistula location (upper vs lower arm; logOR, -1.9; 95% CI, -3.2 to 0.7; P = .002). CONCLUSIONS: There is significant heterogeneity in the three-dimensional geometry of AVFs, in particular, arterial nonplanarity and curvature. In this largest cohort of AVF geometry to date, the effect of individual geometric correlates on maturation is uncertain but supports the premise that future modeling studies will need to acknowledge the complex geometry of AVFs.

Vascular access in lipoprotein apheresis: a retrospective analysis from the UK's largest lipoprotein apheresis centre.

INTRODUCTION: Lipoprotein apheresis (LA) has proven to be an effective, safe and life-saving therapy. Vascular access is needed to facilitate this treatment but has recognised complications. Despite consistency in treatment indication and duration there are no guidelines in place. The aim of this study is to characterise vascular access practice at the UK's largest LA centre and forward suggestions for future approaches. METHODS: A retrospective analysis of vascular access strategies was undertaken in all patients who received LA treatment in the low-density lipoprotein (LDL) Apheresis Unit at Harefield Hospital (Middlesex, UK) from November 2000 to March 2016. RESULTS: Fifty-three former and current patients underwent 4260 LA treatments. Peripheral vein cannulation represented 79% of initial vascular access strategies with arteriovenous (AV) fistula use accounting for 15%. Last used method of vascular access was peripheral vein cannulation in 57% versus AV fistula in 32%. Total AV fistula failure rate was 37%. CONCLUSIONS: Peripheral vein cannulation remains the most common method to facilitate LA. Practice trends indicate a move towards AV fistula creation; the favoured approach receiving support from the expert body in this area. AV fistula failure rate is high and of great concern, therefore we suggest the implementation of upper limb ultrasound vascular mapping in all patients who meet treatment eligibility criteria. We encourage close ties between apheresis units and specialist surgical centres to facilitate patient counselling and monitoring. Further prospective data regarding fistula failure is needed in this expanding treatment field.

The effects of alcohol on coagulation in trauma patients: interpreting thrombelastography with caution.

BACKGROUND: The effects of alcohol on coagulation after trauma remain unclear. In vitro studies show that alcohol may decrease clot strength and inhibit fibrinolysis. Observational data indicate that alcohol leads to altered thrombelastography (TEG) parameters indicative of impaired clot formation. Clinical studies have been inconclusive to date. METHODS: Longitudinal plasma samples were prospectively collected from 415 critically injured trauma patients at a single Level 1 trauma center and were matched with demographic and outcome data. Citrated kaolin TEG and standard coagulation measures were performed in parallel. Univariate and group comparisons were performed by alcohol status, with subsequent linear and logistic regression analysis. RESULTS: A total of 264 patients (63.6%) had detectable blood alcohol levels (EtOH, >10 mg/dL). These patients were primarily male (87% vs. 79%), were bluntly injured (77% vs. 59%), and had lower median Glasgow Coma Scale (GCS) score (9.5 vs. 14, all p < 0.05) than the EtOH-negative patients. There were no notable differences in pH (7.29 vs. 7.31, p = nonsignificant) or injury severity (median Injury Severity Score [ISS], 11 vs. 14; p = nonsignificant) between the groups. The alcohol-positive patients had a prolonged TEG citrated kaolin R-time (reaction time), or time to initial clot formation (5.91 minutes vs. 4.43 minutes, p = 0.013), prolonged K-time (kinetics time), or time to fixed level of clot strength (1.77 minutes vs. 1.43 minutes, p = 0.036), and decreased α angle (66.5 degrees vs. 70.2 degrees, p = 0.001). In multiple linear regression, for every 10-mg/dL increase in EtOH, R-time was prolonged by 3.84 seconds (p = 0.015), and α angle decreased by 0.11 degrees (p = 0.013). However, in multiple logistic regression analyses, EtOH was a negative predictor of coagulopathy by international normalized ratio (>1.3) and was not predictive of transfusion requirements or early or late mortality. CONCLUSION: Patients with elevated EtOH present with impaired clot formation as assayed by TEG, but this does not correlate with standard measures of coagulopathy or with outcome. Reliance on TEG for determining coagulopathy in intoxicated trauma patients may lead to a misperceived hypocoagulable state and inappropriate transfusion. TEG appears to be affected by EtOH in a previously unreported way, warranting further investigation. LEVEL OF EVIDENCE: Prognostic and epidemiologic study, level III.

Safety of nephrectomy in morbidly obese donors.

OBJECTIVES: To satisfy donor organ shortage, overweight and obese donors are becoming a greater proportion of the kidney donor pool. Although good safety data exist in overweight and moderately obese individuals (body mass index = 25 to 35 kg/m²), there is little information about outcomes in morbidly obese donors (body mass index ≥ 40 kg/m²). The purpose of this study was to review the experience with morbidly obese donors in a single center and assist in the discussion about the feasibility of nephrectomy in such cases. MATERIALS AND METHODS: Outcomes of nephrectomy in morbidly obese donors between January 2005 and June 2010 were reviewed retrospectively and compared with outcomes in nonobese donors. RESULTS: Of 386 nephrectomies, 7 involved morbidly obese donors. Mortality and major complication rates were low in all body mass index categories. A high incidence of minor postoperative complications was observed in the morbidly obese, with 57% morbidly obese patients requiring treatment for complications including respiratory infection, compared with 30% in nonobese donors (P < .05). There were no significant differences in mean operative time, estimated blood loss, and length of hospital stay between all body mass index categories. Limited follow-up data (mean, 20 mo) showed similar renal function parameters between groups. CONCLUSIONS: The limited data suggest that nephrectomy may be feasible in selected morbidly obese donors. Further study is needed before major conclusions can be made.

Investigation and treatment of a complicated inflammatory aortoiliac aneurysm.

Inflammatory abdominal aortic aneurysms (IAAAs) account for 5% to 10% of all abdominal aortic aneurysms, occurring primarily in males. Their true etiology is unknown. Symptoms and signs of IAAA are so variable that they present to a wide range of specialties. There is debate in the literature whether IAAA is a manifestation of systemic autoimmune disease. We describe the case of a young female patient with complicated inflammatory aortoiliac aneurysmal disease, illustrating diagnostic and treatment challenges that remain. Our patient had a positive autoantibody screen, raised erythrocyte sedimentation rate, positive enzyme-linked immunosorbent spot test, and saccular aneurysms, including infective and inflammatory etiologies in her differential diagnosis. Early diagnosis is crucial to limit disease progression, morbidity, and mortality. Medical management is important to address the underlying disease process, but a combination of endovascular and open surgical intervention is often necessary for definitive treatment. Available evidence offers plausibility for benefit of endovascular intervention over open repair.

Live donor kidney transplantation: attitudes of patients and health care professionals concerning the pre-surgical pathway and post-surgical follow-up.

OBJECTIVES: We surveyed the following groups of individuals concerning their attitudes towards the pathway leading up to live donor kidney transplantation (LDKT) and post-operative follow-up: kidney transplant (deceased and live donor) recipients, live kidney donors and medical and nursing staff caring for end-stage renal disease and dialysis patients. MATERIALS AND METHODS: Participants were recruited within a tertiary renal and transplant centre and invited to complete anonymized questionnaires, be involved in focus groups and undertake structured interviews. RESULTS: A total of 464 participants completed the questionnaire (36% health care professionals and 64% patients). Most perceived donor risk as small or very small (62%), and 49% stated that a potential donor should be given up to 3 months to reconsider the decision to donate. Participants were almost equally divided as to whether consensus of the donor's family is necessary (46%) or not (44%) in LDKT. Seventy-one percentage of the participants suggested that patients have a greater appreciation of a LDKT if they have been on dialysis; 58% of participants thought that donor and recipient should recuperate beside each other after surgery; 45% thought that the post-operative follow-up for the donor should last up to a year; and 83% thought that donor follow-up should include medical status and quality of life. In the interviews, participants expressed several interesting views. CONCLUSIONS: Participants believed that LDKT is safe for the donor, and the pathway to surgery and post-operative follow-up should be performed in a way that ensures lack of coercion and includes family support and an extensive post-operative follow-up.

Malignancies confined to disused arteriovenous fistulae in renal transplant patients: an important differential diagnosis.

BACKGROUND: Swelling in an arteriovenous fistula (AVF) is commonly caused by thrombosis, aneurysm and infection. However, due to the increased risk of malignancy after transplantation, this should also be considered. PATIENTS: We discuss 4 patients with malignancy confined to an AVF after renal transplantation presenting in a 2-year period. Angiosarcoma was diagnosed in 3 patients and the other had post-transplant lymphoproliferative disorder (PTLD). Angiosarcoma behaves aggressively and 2 of our patients died within 6 months of diagnosis. There are 6 previous cases and 5 died within 16 months of diagnosis. PTLD at AVFs has not been documented previously. CONCLUSION: Malignancy at an AVF is a rare but important differential that can impact significantly on patient morbidity and mortality. Predilection for malignancy at an AVF is not understood. We review the literature and discuss possible aetiologies.

Focal central white matter lesions in Alexander disease.

Alexander disease is a neurodegenerative disorder of the central white matter caused by dominant mutations in GFAP, the gene encoding glial fibrillary acidic protein. Magnetic resonance imaging pattern recognition studies have established characteristic radiologic phenotypes for this disorder. In some cases, however, genetically confirmed cases do not express these features, and several reports have identified "atypical" radiologic findings in Alexander disease patients. Here, the authors report 3 genetically confirmed Alexander disease cases with focal central white matter lesions that, upon longitudinal clinical and radiologic evaluation, appear to reflect an atypical Alexander disease magnetic resonance imaging phenotype and not another pathophysiologic process such as encephalitis, infarction, or neoplasm.

The use of an implantable Doppler flow probe in kidney transplantation: first report in the literature.

OBJECTIVES: After a kidney transplant, surveillance of the graft blood supply is crucial. Any delay in detecting compromised graft perfusion affects organ survival. Current practice uses Doppler ultrasound to monitor vessel patency and graft perfusion and is performed repeatedly after kidney and pancreas transplant. We have used an implantable probe that allows for easy vessel attachment and safe, continuous, audible monitoring of vascular anastomoses. It has been used to observe microvascular tissue transplants, free flaps, and pediatric liver transplants, but as yet, it has not been used to monitor kidney allografts. We feel a transplanted kidney could benefit greatly from continuous blood flow monitoring. MATERIALS AND METHODS: To assess the feasibility of the probe in a renal transplant patient, we used the probe in 15 consecutive transplant recipients. RESULTS: Only 1 Doppler ultrasound was ordered during the 15 admissions compared with scans that are routinely ordered. There were no complications and all probes were removed easily. CONCLUSIONS: This probe can identify transplanted organs that are threatened owing to flagging or cessation of the blood supply, and allow for immediate intervention. This technique may save precious organs. Further controlled studies are needed to assess the use of the probe in routine clinical practice.