Kidney retransplants after initial graft loss to vascular thrombosis

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.

Patient Selection for Kidney Transplant

The incidence of end-stage renal disease has continued to increase. Similarly, the number of patients living with a functioning renal allograft has also increased. Transplantation has improved with advances in surgical techniques, immunosuppression, and better control of comorbid conditions. Transplantation is transformative and offers the greatest potential for restoring a healthy, productive, and durable life to appropriately selected patients. This article describes factors to address in selection of renal transplant candidates and discusses commonly encountered perioperative events. Paramount to selecting appropriate candidates is the collaboration between a multidisciplinary team focused on a systematic process guided by protocols and common practices.

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.

Late Allograft Renal Vein Thrombosis Treated With Anticoagulation Alone: A Case Report

BACKGROUND

Allograft renal vein thrombosis is a rare complication of kidney transplantation. Most cases occur in the first 2 weeks after transplantation, but there are cases described many years after the transplant surgery. Allograft loss is the usual outcome.

METHODS

We present a case of a renal transplant recipient with allograft renal vein thrombosis associated with deep venous thrombosis of a lower limb, 9 years after transplantation. He was successfully treated with anticoagulation alone, with recovery of allograft function.

RESULTS

The patient was given unfractioned heparin and elastic compression stockings. Five days later, the patient recovered diuresis and hemodialysis treatment was discontinued. Doppler ultrasound was done and revealed partial re-permeabilization of allograft renal vein, with maximal velocity of 15 cm/s. After 30 months of follow-up, the patient was maintained on oral anticoagulation with warfarin, and no thromboembolic or hemorrhagic events were documented. The patient's serum creatinine was stable, between 1.6 and 1.8 mg/dL.

CONCLUSIONS

Our patient demonstrated that anticoagulation alone and dialytic support might be able to promote total recovery of allograft function after renal vein thrombosis.

Immediate Vascular Complications After Kidney Transplant: Experience from 2100 Recipients

OBJECTIVES

Vascular complications, especially immediate events during kidney transplant, are the major cause of graft loss, and prompt surgical intervention is important for salvage of the graft and recipient. In this study, our aim was to show our experiences with vascular interventions and their effects on graft outcomes in transplant patients with suspected immediate vascular events.

MATERIALS AND METHODS

Over 24 years (from 1990 to 2014), 2100 renal transplant procedures (1562 living and 538 deceased donors) were performed by one fixed team. We reviewed the recipients to find cases with immediate vascular complications, including artery or vein kinking or torsion, renal artery thrombosis, and renal vein thrombosis. Diagnosis of a vascular event was suspected when urinary output suddenly stopped and was confirmed by color Doppler ultrasonography or immediate exploration. Characteristics of the patients and events, surgical interventions for saving grafts, and graft outcomes were assessed.

RESULTS

Our study included 28 vascular accidents (1.3% of total renal transplants). Arterial kinking or torsion, venous kinking or torsion, renal artery thrombosis, and renal vein thrombosis occurred in 11 (0.52%), 2 (0.09%), 12 (0.57%), and 3 patients (0.14%). Nine of the 11 cases of arterial kinking occurred with use of internal iliac artery. Eleven of 13 grafts with vascular kinking or torsion were saved by immediate surgical intervention, but only 4 grafts in patients with renal artery thrombosis and only 1 graft in patients with renal vein thrombosis were saved by surgical intervention. Delayed graft function occurred in all cases of saved renal artery and renal vein thrombosis but only in 5 cases (4 arterial and 1 venous) of vascular kinking or torsion.

CONCLUSIONS

The incidence of immediate vascular complications was 1.3% in our study. Sudden cessation of urine after renal transplant is a warning sign, and immediate diagnosis of vascular events will help salvage the graft with proper intervention.

Acute renal artery thrombosis after kidney transplantation

Early kidney transplant loss as a result of acute thrombosis of the renal artery remains a constant and devastating complication, with an incidence of 0.2-7.5%. While uncommon, arterial obstruction in the early postoperative period is a surgical emergency and must be ruled out if previously established diuresis ceases suddenly. Arterial thrombosis may occur as a result of injury to a diseased artery, problems with anastomoses, hypercoagulability or malpositioning of the allograft. In this study, we analyzed data on a group of 105 renal transplant recipients who presented with acute postoperative graft dysfunction between January 2006 and May 2012, to identify cases of acute renal artery thrombosis. We report on our experience of immediate re-transplantation following early kidney transplant thrombosis. Overall, two (1.9%) patients suffered early (within 48 hours of surgery) allograft renal artery thrombosis. In both patients, transplantation had not been complicated by atherosclerotic lesions or other thrombophilic states and postoperative diuresis had been successfully achieved, but diuresis ceased abruptly during the early postoperative period. Emergent duplex ultrasound scans were performed and acute renal artery thrombosis was detected in both patients. The patients were operated immediately and retransplantation procedures were conducted. We have reported our experience of immediate retransplantation following early primary graft dysfunction due to renal artery thrombosis. In conclusion, close monitoring of postoperative diuresis and, if necessary, immediate retransplantation in this situation can prove to be a successful treatment for preventing graft loss.

Vascular complication in live related renal transplant: An experience of 1945 cases

Introduction and Objective:

Among the surgical complications in renal transplantation, the vascular complications are probably most dreaded, dramatic, and likely to cause sudden loss of renal allograft. We present our experience and analysis of the outcome of such complications in a series of 1945 live related renal transplants.

Materials and Methods:

One thousand nine hundred and forty five consecutive live related renal transplants were evaluated retrospectively for vascular complications. Complications were recorded and analyzed for frequency, time of presentation, clinical presentation, and their management.

Results:

The age of patients ranged from 6 to 56 years (mean = 42). Vascular complications were found in 25 patients (1.29%). Most common among these was transplant renal artery stenosis found in 11 (0.58%), followed by transplant reznal artery thrombosis in 9 (0.46%), renal vein thrombosis in 3 (0.15%), and aneurysm formation at arterial anastmosis in 2 (0.10%) patient. The time of presentation also varied amongst complications. All cases of arterial thrombosis had sudden onset anuria with minimal or no abdominal discomfort, while venous thrombosis presented as severe oliguria associated with intense graft site pain and tenderness. Management of cases with vascular thrombosis was done by immediate surgical exploration. Two patients of renal artery stenosis were managed with angioplasty and stent placement.

Conclusions:

Major vascular complications are relatively uncommon after renal transplantation but still constitute an important cause of graft loss in early postoperative period. Aneurysm and vessel thrombosis usually require graft nephrectomy. Transplant renal artery stenosis is amenable to correction by endovascular techniques.

Increased Risk of Hemorrhagic Complications in Renal Allograft Recipients Receiving Systemic Heparin Early Posttransplantation

The aim of this paper is to document the risk of hemorrhagic complications in renal allograft recipients requiring systemic heparinisation within the first 2 weeks posttransplantation.

METHODS

A retrospective chart review of 326 RA recipients from January 1998 to July 2003 was subjected to statistics by SPIDA with P values <.05 considered significant.

RESULTS

16/326 (4.9%) recipients were initiated on intravenous (IV) heparin within the study period. Enoxaparin was subsequently used in 10/16 (62.5%) of these recipients. Intravenous heparin was instituted at a median 8 (1-14) days posttransplantation. Hemorrhagic complications occurred in 10/16 (62.5%) recipients on IV heparin versus 11/310 (3.5%) nonanticoagulated RA recipients (P = .0001). Hemorrhage occurred at a mean 9.75 (2-43) days into the course of IV heparin. The median peak APTT 24 hours prior to hemorrhage in RA recipients on heparin was 68.5 (58-180) versus a median peak APTT of 70 (50-140) among recipients on heparin who did not sustain a hemorrhagic complication (P = .30). A major intervention (predominantly surgery) was required in 6/16 (37%) recipients on IV heparin versus 7/310 (2.2%) nonheparinised RA recipients (P < .0001). Enoxaparin was instituted at a mean 22.5 (4-55) days posttransplantation. Delayed hemorrhage subsequently occurred in 4/10 (40%) recipients on enoxaparin. In conclusion, major and minor hemorrhagic complications occur more commonly among recipients requiring early post transplant IV heparin. Hemorrhage occurred despite APTT monitoring with APTT levels tending to be similar in RA recipients with versus without complications. Delayed hemorrhage was also seen with the subsequent use of enoxaparin.

Aspectos quirúrgicos en los terceros y cuartos retrasplantes renales

INTRODUCTION AND OBJECTIVES

A quarter of patients waiting for kidney transplantation are patients with previous graft failure. Outcome of first and second renal transplant make these the gold standard for end renal stage disease, but this is not so clear in the case of third and further renal transplant, especially at the time of organ shortage. We revise our experience in patients with three or more kidney transplants focusing on surgical aspects and graft outcome.

MATERIAL AND METHOD

1364 renal transplants have been carried out in our centre since 1975 until December 2003. We have retrospectively revised the 34 patients with three renal transplants and the 5 with four. We analyse the surgical technique, surgical complications and graft outcome.

RESULTS

Mean age was 42 years (21-65). Average mismatches between donor and recipient was 3.2. All kidneys, but one case of living donor, were harvested from cadaver donors, mostly in multiple organ-procurement. Average time from the last renal transplant was 5 years (3 days-17 years) and from the last transplant carried out in the iliac fossa reused until the new transplant was 9 years (3 days- 17.5 years). All implants were performed through an iterative lumboliliac incision (25 on the right side, 11 on the left one and in 3 cases where side was not registered). Mean average duration of the procedure was 166 minutes (100-300). Nephrectomy of previous graft at the moment of the implant was carried out in 13 patients (33%). Vascular anastomosis was made on the common iliac vessels (50%) or on the external ones (50%) in end to side way, Ureteroneocystostomy was performed in an extravesical way except in 1 patient with cutaneous diversion. Vascular complications were 4 haemorrages (1 patient died), 3 venous and 2 arterial thrombosis. We had an abscess secondary to intestinal fistulae. Other surgical complications were 4 lymphoceles, three of them needed surgical treatment, and one perirenal haematoma treated in a conservative way. No urological complications were seen. In total 6 grafts (15%) were lost due to surgical complications. Graft actuarial survival rate at 1 year was 65%, 40% at 5 and 28% at 10 years.

CONCLUSIONS

Three and four renal transplant survival rates are shorter than first and second ones. Iterative access through lumboiliac incision is associated with a higher vascular complication rate, probably in these patients a transperitoneal access would be better. Multicentric studies with higher numbers of patients are needed to define more clearly which patients would benefit from multiple kidney retransplants.

Bleeding and Thrombosis in High-Risk Renal Transplantation Candidates Using Heparin

BACKGROUND

Heparin can reduce the risk of renal artery/vein thrombosis in renal transplant patients with hypercoagulable states (HCS), but is associated with a high bleeding risk. Little is known about risk factors for this bleeding risk or the optimal anticoagulation target.

OBJECTIVE

To determine factors associated with this bleeding risk and determine the optimal partial thromboplastin time (PTT) ratio.

METHODS

We retrospectively reviewed medical records of consecutive adult renal transplant recipients administered heparin for perioperative renal thrombosis prevention (1998–2002).

RESULTS

Twenty-eight (3.86%) of 725 consecutive renal transplant recipients received heparin to prevent renal thrombosis. Eighteen patients (64.3%) had clinically important bleeding (14 major bleeding). Patients with and without bleeding were similar in baseline demographic characteristics and overall mean PTT. Bleeding occurred at a mean PTT ratio of 2.5 ± 1, higher than the overall mean in bleeders and nonbleeders (p = 0.001). Among postoperative characteristics, higher maximum PTT (p = 0.052) and prolonged surgical antibiotic prophylaxis (p = 0.053), particularly with cefotetan (p = 0.091), trended toward a significant association with bleeding. Two renal thrombotic episodes occurred, both at PTT ratios <1.5. A PTT ratio of 1.5–1.9 resulted in no thrombosis and ≤4.2% bleeding.

CONCLUSIONS

The benefits and risks of therapeutic heparin anticoagulation in renal transplant patients with HCSs were confirmed. Higher PTTs and cefotetan antibiotic surgical prophylaxis could contribute to bleeding. The optimal PTT ratio appeared to be 1.5–1.9 to prevent thrombosis and limit bleeding risk.

Hypercoagulability in renal transplant recipients. Identifying patients at risk of renal allograft thrombosis and evaluating strategies for prevention

Renal transplantation improves survival and quality of life for patients with end-stage renal disease (ESRD). Improvements in immunosuppressive therapy have reduced early allograft loss due to acute rejection to very low levels. Early allograft loss, due to acute thrombotic complications, remains a constant and proportionally increasing complication of renal transplantation. Identifying risk factor(s) for thrombosis amenable to preventive strategies has been elusive. Epidemiological studies have attempted to define risk in terms of modifiable (drugs, dialysis modality, surgical procedure) and non-modifiable (age, diabetes mellitus, vascular anomalies) factors, or identify changes in coagulation or fibrinolysis promoting a more thrombotic state. Most recently the evolution of thrombophilia research has established the potential for inherited hypercoagulability to predispose to acute allograft thrombosis. Inheritance of the factor V Leiden (FVL), prothrombin G20210A mutation, or the presence of antiphospholipid antibodies (APA) may increase the risk of renal allograft thrombosis approximately 3-fold in selected patients. Patients with ESRD due to systemic lupus erythematosus (SLE) appear at particularly high risk of thrombosis, especially if they have either APA or detectable beta(2)-glycoprotein-1. Data for other hypercoagulable states such as hyperhomocystinemia or the C677T polymorphism of the methylenetetrahydrofolate reductase gene are deficient. Patients with APA, FVL, or prothrombin G20210A mutation also appear to have greater graft loss due to vascular rejection, possibly reflecting immunological injury upon the vascular wall exacerbated or induced by the prothrombotic state. While substantial in vitro data suggest cyclosporine is prothrombotic, an independent clinical association with allograft thrombosis is unproven. Interventions to reduce thrombotic risk including heparin, warfarin, and aspirin have been evaluated in both selected high-risk groups (heparin and warfarin) and unselected populations (heparin and aspirin). In unselected patients at low clinical risk, aspirin (75-150 mg/day) with or without a short period of unfractionated heparin (5000U twice a day for 5 days) appears to reduce the risk of renal allograft thrombosis significantly with a low risk of bleeding, especially when compared with low molecular weight heparins which risk accumulation in renal failure. In high-risk groups (identified thrombophilic risk factor, previous thrombosis, or SLE) longer period of heparin, with or without aspirin and maintenance with warfarin, should be considered. Re-transplantation following graft loss due to vascular thrombosis can be undertaken with a low risk of recurrence. Further prospective studies evaluating both putative risk factors and intervention strategies are required to determine whether routine clinical screening for thrombophilic factors is justified.

Antiphospholipid antibodies and renal transplantation: a risk assessment

Data from 110 transplanted patients show that the presence of antiphospholipid antibodies (aPL) at the time of transplantation is an important risk factor for early renal allograft failure. Sera were tested for IgG, IgM and IgA to CL, PS, PE and PC. Haemodialysis patients had a significantly higher incidence of aPL compared to patients who did not receive haemodialysis (P = 0.0171). aPL-positive ESRD patients on peritoneal dialysis (CAPD) or who had never received haemodialysis were at maximal risk; 100% failure (P = 0.0022). aPL-positive patients receiving haemodialysis were not at such risk. Biopsy findings from the failed kidneys show abundant fibrin deposition in the microvasculature. Serial blood samples from transplanted patients showed aPL titres to decrease immediately after transplant and increase after removal of the failed graft, indicating that aPL specifically target the allografts. To confirm this, we were able to isolate aPL from a failed graft after transplant nephrectomy. Ninety-seven per cent of the aPL-positive patients' historic pre-transplant serum samples demonstrated the presence of the same aPL specificity detected in the final crossmatch sera. The exposure to heparin during haemodialysis suggested to us that heparin reduces the risk of clotting in aPL positive transplant candidates. To lessen the risk of graft loss in aPL positive kidney transplant patients (including CAPD), subcutaneous heparin was administered peri- and post-operatively. To date, none of the heparin-treated aPL-positive transplanted patients suffered an early graft loss. Further, they experienced fewer rejection episodes requiring biopsy and thus are prescribed less steroid therapy than patients not treated with heparin.

Coagulation: consultative hemostasis

Clinical hematologists are frequently consulted for the care of hospitalized patients with complicated coagulopathies. This chapter provides an update on the scientific and clinical advances noted in disseminated intravascular coagulation (DIC) and discusses the challenges in hemostasis consultation. In Section I, Dr. Marcel Levi reviews advances in our understanding of the pathogenic mechanisms of DIC. Novel therapeutic strategies that have been developed and evaluated in patients with DIC are discussed, as are the clinical trials performed in patients with sepsis. In Section II, Dr. Lawrence Leung provides an overview of the challenging problems in thrombosis encountered in the inpatient setting. Patients with deep vein thrombosis that is refractory to conventional anticoagulation and those with extensive mesenteric thrombosis as well as the evaluation of a positive PF4/heparin ELISA in a post-operative setting are discussed. Novel treatments for recurrent catheter thrombosis in dialysis patients is addressed as well. In Section III, Dr. Julie Hambleton reviews the hemostatic complications of solid organ transplantation. Coagulopathy associated with liver transplantation, contribution of underlying thrombophilia to graft thrombosis, drug-induced microangiopathy, and the indication for postoperative prophylaxis are emphasized. Dr. Hambleton reviews the clinical trials evaluating hemostatic agents in patients undergoing liver transplantation.

Pretransplant peritoneal dialysis and graft thrombosis following pediatric kidney transplantation: a NAPRTCS report

Graft thrombosis is a common cause of graft failure in pediatric renal transplantation. Several previous studies, including a North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) review of pretransplant dialysis status and graft outcomes, have described a potential correlation of peritoneal dialysis (PD) and graft thrombosis. This issue is of particular concern for pediatric transplant programs as more than 65% of children with end stage renal disease are treated with PD. We reviewed 7247 pediatric renal transplants performed between 1987 and 2001. Thrombosis was the cause of graft loss in 2.7% (199) of all the transplants performed. Among failed transplants, thrombosis was the third most common cause of graft loss in both index (11.6%) and subsequent transplants (14.5%). Thrombosis becomes the most common cause of graft failure (21%, 61/294) if one looks at transplants in the later cohort, from 1996 to 2001. This change is primarily because of a decrease in the incidence of acute rejection. In the PD group, 3.4% of all grafts were lost as a result of thrombosis. This compares with 1.9% in the hemodialysis group, 2.4% in the pre-emptive transplant group, and 4.1% among patients who received both dialysis modalities. There was a statistically significant difference in thrombosis failure risk in the different dialysis groups (p = 0.005) with those who received only peritoneal dialysis having the highest risk. Additional significant risk factors for graft thrombosis included; cadaver donor source (p < 0.001), cold ischemia time >24 h (p < 0.001), history of prior transplant (p < 0.001), donor age <6 yr (p < 0.001), and >5 pretransplant blood transfusions (p = 0.02). Using stepwise proportional hazards modeling, only pretransplant peritoneal dialysis, >24 h cold ischemia time, prior transplant, and donor age <6 yr were simultaneously associated with an increased risk of thrombosis. We conclude that pretransplant PD is associated with an increased risk of graft thrombosis. Special precautions should be undertaken in pediatric renal transplant patients who have received PD, especially infants and young children.

Antiphospholipid antibodies: discovery, definitions, detection and disease

Antiphospholipid antibodies (aPL) are immunoglobulins of IgG, IgM and IgA isotypes that target phospholipid (PL) and/or PL-binding plasma proteins. Detection of aPL in the laboratory is done currently by both immunoassays and functional coagulation tests. Convention defines aPL specificity in immunoassays according to the particular PL substrate present, for example aPS represents antiphosphatidylserine antibodies. This may be technically incorrect inasmuch as a particular PL may be responsible for binding and highly concentrating a specific plasma protein, the latter then becomes the target for the aPL. The binding of beta(2)GP-I (apolipoprotein H) to the negatively charged PL, cardiolipin (CL) provides a good example of this circumstance. In contrast, aPL which specifically prolong coagulation times in in vitro are called lupus anticoagulants (LA). The precise PL target(s) of the aPL responsible for LA activities are unknown and often debated. The persistent finding of aPL in patients in association with abnormal blood clotting and a myriad of neurological, obstetrical and rheumatic disorders often compounded by autoimmune diseases has led to an established clinical diagnosis termed antiphospholipid syndrome (APS). The common denominator for these APS patients is the presence of circulating aPL on two or more occasions and the observation of events attributable to abnormal or accelerated blood clotting somewhere in vivo. The purpose of this review is to collect, collate, and consolidate information concerning aPL.

Management of thrombophilia in renal transplant patients

Renal allograft recipients with thrombophilia (a hypercoagulable state) are at higher risk for early allograft loss. Following an episode of allograft renal vein thrombosis in a patient subsequently diagnosed with protein C deficiency, we adopted universal screening for hypercoagulable risk factors. Patients with a history of a thromboembolic event underwent laboratory screening for thrombophilia. Eight patients with a defined hypercoagulable disorder or a strong clinical history of thrombosis even in the absence of hematologic abnormalities were treated with anticoagulation following renal transplantation. We reviewed the outcomes of these eight patients and all renal transplant recipients at our center who developed thrombotic complications after renal transplantation. Since the introduction of universal screening for hypercoagulable risk factors, 235 consecutive transplants were performed without allograft thrombosis. Eight patients with evidence of thrombophilia, recognized before renal transplantation, received perioperative heparin and postoperative oral anticoagulation. Two of these eight patients developed perinephric hematomas requiring evacuation, blood transfusion, and temporary withholding of anticoagulation. Of interest, two of the remaining 227 patients, not identified with thrombophilia before surgery, developed thrombotic complications after renal transplantation. A hypercoagulable disorder was subsequently documented in each. Identifying patients with thrombophilia before transplantation and defining their management presents many challenges. The risk of allograft thrombosis must be weighed against the risk of perioperative bleeding and the need for long-term anticoagulation. Recommendations for managing thrombophilia in renal transplant recipients are suggested based on our experience and review of the literature.

Renal allograft loss due to proximal extension of ileofemoral deep venous thrombosis

Renal allograft recipients with thrombophilic (hypercoagulable) states are at higher risk for early allograft loss. Presumably, the combination of endothelial injury at surgery and thrombophilia predisposes to arterial or venous thrombosis. Of 270 consecutive renal transplants at our center one allograft failed secondary to renovascular thrombosis. At exploration the iliac and renal veins were thrombosed. Thrombectomy and re-implantation were attempted, but unsuccessful. Also noted at surgery was extensive clot in the femoral vein that could not be removed by embolectomy catheters. Post-operatively, a Doppler ultrasound confirmed the presence of extensive deep venous thrombosis (DVT) in the femoral and popliteal veins. The adherent nature of this clot, the extent of clot found less than 12 h after renal transplantation and the absence of leg edema suggested that the DVT existed prior to surgery. This case demonstrates that a pre-existing, asymptomatic DVT can precipitate allograft thrombosis and highlights the importance of diagnosing thrombophilia in patients undergoing renal transplantation. Current practices in our unit have evolved to include screening for thrombophilia in all patients with a suggestive history. As thrombophilic states are increasingly appreciated in the end-stage renal disease population, effective management of these patients while on hemodialysis and at the time of renal transplantation presents an ongoing challenge.

Are wound complications after a kidney transplant more common with modern immunosuppression?

BACKGROUND

The most common surgical complication after a kidney transplant is likely related to the wound. The purpose of this analysis was to determine the incidence of, and risk factors for, wound complications (e.g., infections, hernias) in kidney recipients and to assess whether newer immunosuppressive drugs increase the risk for such complications.

METHODS

Between January 1, 1984 and September 30, 1998, we performed 2013 adult kidney transplants. Of these 2013 recipients, 97 (4.8%) developed either a superficial or a deep wound infection. Additionally, 73 (3.6%) recipients developed either a fascial dehiscence or a hernia of the wound. We used univariate and multivariate techniques to determine significant risk factors and outcomes.

RESULTS

Mean time to development of a superficial infection (defined as located above the fascia) was 11.9 days posttransplant; to development of a deep infection (defined as located below the fascia), 39.2 days; and to development of a hernia or fascial dehiscence, 12.8 months. By multivariate analysis, the most significant risk factor for a superficial or deep wound infection was obesity (defined as body mass index>30 kg/m2) (RR=4.4, P=0.0001). Other significant risk factors were a urine leak posttransplant, any reoperation through the transplant incision, diabetes, and the use of mycophenolate mofetil (MMF) (vs. azathioprine) for maintenance immunosuppression (RR=2.43, P=0.0001). Significant risk factors for a hernia or fascial dehiscence were any reoperation through the transplant incision, increased recipient age, obesity, and the use of MMF (vs. azathioprine) for maintenance immunosuppression (RR=3.54, P=0.0004). Use of antibody induction and treatment for acute rejection were not significant risk factors for either infections or hernias. Death-censored graft survival was lower in recipients who developed a wound infection (vs. those who did not); it was not lower in recipients who developed an incisional hernia or facial dehiscence (vs. those who did not).

CONCLUSIONS

Despite immunosuppression including chronic steroids, the incidence of wound infections, incisional hernias, and fascial dehiscence is low in kidney recipients. As with other types of surgery, the main risk factors for postoperative complications are obesity, reoperation, and increased age. However, in kidney recipients, use of MMF (vs. azathioprine) is an additional risk factor -one that potentially could be altered, especially in high-risk recipients.