Assessment of live kidney donors by magnetic resonance angiography: reliability and impact on outcomes.

BACKGROUND: Kidney allograft retrieval from live donors requires accurate determination of kidney anatomy prior to surgery, particularly the arterial supply. Traditionally, conventional angiography has been used to obtain this information. Magnetic resonance angiography (MRA) offers a non-invasive, cost-effective alternative, but has been considered to be less accurate. Despite this criticism, many centers have moved to MRA screening of potential kidney donors. The objective of this study is to evaluate our experience of the reliability of MRA in determining the arterial anatomy of living kidney donors as compared to the intra-operative findings. METHODS: We performed a retrospective review of gadolinium-enhanced, ultra-fast, three-dimensional, spoiled gradient-echo MRA in live kidney donors in the Southern Alberta Transplant Program and compared these results with the intra-operative findings during nephrectomy, as the gold standard. RESULTS: Of the 66 patients, an accessory renal artery was found intra-operatively in eight cases; two of which were erroneously diagnosed as normal by MRA. The negative predictive value for MRA was 0.97, false-negative rate was 0.25, and sensitivity was 0.75. No patient experienced side-effects from the MRA procedure. No donor needed conversion to open nephrectomy because of an undetected accessory renal artery. One allograft with an accessory renal artery developed thrombosis of the lower pole of the kidney despite arterial reconstruction. Kidney function in the recipient of this allograft was excellent and there was no urinary leak. CONCLUSION: In our hands, MRA determined the vascular anatomy of potential kidney donors with an acceptable negative predictive value of 97%.

Native arteriovenous fistulas: correlation of intra-access blood flow with characteristics of stenoses found during diagnostic angiography.

Surveillance of the intra-access blood flow (Qa) has improved identification of thrombosis risk (Qa < or = 500 ml/minute), and these patients are referred for angiogram and angioplasty. The purpose of this study was to correlate the Qa with patient and stenotic lesion characteristics both before and after angioplasty in a retrospective cohort of 210 patients who were preselected on the basis of reduced Qa (369 +/- 121 ml/minute). Angiograms revealed a total of 643 stenoses, and all patients had at least one significant stenosis (>50% luminal narrowing). There was no significant association between the preangioplasty Qa and the number, location, or length of stenoses, but there was a significant negative correlation between the degree of stenosis and the preangioplasty Qa. Five hundred eighty stenoses in 190 patients were treated with angioplasty; the postangioplasty Qa was 633 +/- 208 ml/minute. Of the residual stenoses, all had less than 50% narrowing. There was no correlation between the postangioplasty Qa and the length or degree of stenoses, but there was a significant negative correlation between the postangioplasty Qa and the number of stenoses. We conclude that the primary determinant of reduced preangioplasty Qa is the degree of stenosis, when stenoses are over 50%, whereas the primary determinant of reduced postangioplasty Qa is the number of stenosis. For patients with two or more residual stenoses and failure to achieve Qa > 500 p;ml/minute postangioplasty, the alternative procedure is a prompt surgical revision in order to maintain the goal of access patency.

Renal allograft compartment syndrome: an underappreciated postoperative complication.

PURPOSE: Renal allograft compartment syndrome (RACS) is early graft dysfunction secondary to retroperitoneal hypertension and resultant ischemia. Our purpose was to identify the incidence, therapies and outcomes of patients with RACS. METHODS: All patients who underwent a renal transplant between 2000 and 2005 were reviewed. Patients with signs of acute allograft dysfunction were identified. RACS was diagnosed via visual allograft hypoperfusion and/or with preoperative Doppler ultrasound. RESULTS: Among 458 patients, 11 (2%) were diagnosed with RACS. Characteristics between patient groups were similar. Five (45%) patients displayed adequate initial allograft function after transplantation. Doppler ultrasound was diagnostic. Six (55%) patients displayed poor initial allograft function and were classified as early presenters of RACS. Allograft function improved dramatically upon decompression. CONCLUSIONS: Clinicians must remain aware of RACS as a potential diagnosis when patients display rapid deterioration in kidney performance after good initial allograft function. Doppler ultrasound is useful in diagnosing late presenters.

Bladder vs enteric drainage in simultaneous pancreas-kidney transplantation.

BACKGROUND: As a valid therapeutic option for patients with type 1 diabetes mellitus (IDDM) and secondary diabetic nephropathy, simultaneous pancreas-kidney (SPK) transplantation remains more undeveloped than other solid organ transplantations due to restrictions of surgical techniques, especially modes of exocrine pancreatic secretion. Enteric drainage (ED) has recently been increasingly popular due to the long-term complications with bladder drainage (BD). Objectives. Compare results of SPK transplants with enteric vs bladder exocrine drainage since the beginning of our experience with this type of transplantation. METHODS: From March 1998 to October 2004, 53 SPK transplants were performed, consisting of 30 with bladder drainage (BD) and 23 with enteric drainage (ED). Induction therapy included antilymphocyte globulin (ALG) or anti-CD25 monoclonal antibody. Maintenance regimen consisted of tacrolimus (TAC)/cyclosporine (CsA), mycophenolate mofetil (MMF) and steroids. RESULTS: Mean age of recipients was 39+/-7 in both groups. No anastomosis leakage occurred in either group. Surgical complications were not significantly different between the two groups. Incidence of acute rejection, major infections and cytomegalovirus disease were also similar. However, the BD group was characterized by a slight increase in number of urologic complications, metabolic acidosis and dehydration. The length of initial hospital stay was likewise comparable. All patients with a functional graft no longer required exogenous insulin. BD actuarial patient survival and graft three-year survival were 96 and 86%, respectively. For ED, the respective results were 97 and 91%, respectively. CONCLUSION: Compared with BD, perioperative morbidity is not increased by ED, and ED is not associated with increased long-term pancreas graft failure. These data suggest that ED is superior to BD and should be considered as the preferred technique for simultaneous pancreas-kidney transplants.

Use of a minimally invasive donor nephrectomy program to select technique for live donor nephrectomy.

BACKGROUND: Live donor nephrectomy (LDN) is a major surgical procedure with an accepted low mortality and morbidity. Minimally invasive donor nephrectomy (MIDN) has been shown to decrease the wound morbidity associated with the lumbotomy of the classic open technique. Transplant programs face the challenge of initiating their MIDN programs without jeopardizing the safety of the donor and the graft quality. We present the experience at the University of Calgary after the initiation of a MIDN program, with a preoperative selective approach using the 3 major techniques for LDN. METHODS: From December 2001 to May 2004, 50 consecutive, accepted, live kidney donors were evaluated and chosen to undergo nephrectomy by an open, laparoscopic, or hand-assisted technique. Patients were chosen for a particular technique based on the criteria of vascular anatomy, size of abdominal cavity, previous surgery, and technical implications for the recipient. RESULTS: A total of 15 open, 11 laparoscopic, and 24 hand-assisted nephrectomies were performed. There were no statistically significant differences in sex, age, or body mass index between the groups. There were statistically significant differences in surgical times (P < .001) and in the number of days spent in the hospital (P < .001). All kidneys had primary function. There were 2 conversions in the hand-assisted group and 1 blood transfusion in the open group. Death-censored graft survival was 100% with an observation time of 20 months (SD +/- 9 months; range = 3-32 months). One graft from the hand-assisted group was lost from patient death with functioning graft 8 months after transplant. CONCLUSIONS: The learning curve for MIDN does not necessarily need to impact donor or recipient outcomes. The initiation of an MIDN program can be implemented safely if the cases are selected carefully and the use of the classic open technique is kept as an alternative.