Adena J. Osband, Transplant Surgery Fellow; Nicholas I. Jones, Surgical Resident; Mary Bonomo, Transplant Physician's Assistant; Radi F. Zaki, Attending and Chief of Transplant Surgery, Division of Transplantation, Department of Surgery, Albert Einstein Medical Center, Philadelphia, PA
Adena J. Osband, MD
Transplant Surgery Fellow
Nicholas I. Jones, MD
Mary Bonomo, PA-C
Transplant Physician's Assistant
Radi F. Zaki, MD
Attending and Chief
of Transplant Surgery
Division of Transplantation
Department of Surgery
Albert Einstein Medical Center
Introduction: Kidney transplantation is complicated in patients who have femoral arteriovenous (AV) grafts for hemodialysis access because these grafts alter the flow dynamics at the iliac vessels.
Results and discussion: This paper discusses the cases of two kidney transplant patients who had allografts placed ipsilateral to the femoral access site. Both patients required ligation of their AV grafts postoperatively due to no or poor diastolic arterial flow. The authors review the literature, which identified five similar cases.
Conclusion: To minimize the need for ligation in patients with femoral AV grafts, the authors recommend contralateral placement of the allograft, performing a detailed preoperative workup, or conducting intraoperative ultrasonography.
Hemodialysis access can become complex in patients who have been receiving hemodialysis for extended periods, have a hypercoagulable disease state, or develop superior vena cava syndrome. Once sites in both upper extremities have been exhausted, the next location becomes the femoral vessels.1 Access options include femoral loop arteriovenous (AV) grafts or saphenous vein transposition, with the former being encountered more frequently. As the waiting time for kidney transplants continues to increase, it is likely that transplant surgeons will encounter more end-stage renal disease patients who have functioning femoral AV grafts.
Traditionally, kidney transplants are placed in the iliac fossa, with vascular anastomoses to the common or external iliac artery and vein and easy access to the bladder. In patients who have femoral AV grafts, the flow dynamics across the iliac vessels are greatly altered by this fistulous connection, and this must be factored into the surgical plan.2 The arterial flow is diverted preferentially through the low-resistance system of the AV graft. This may result in increased flow toward the more distal AV graft rather than through the renal artery anastomosis, creating a shunt phenomenon. The iliac vein experiences a significant increase in venous blood pressure and flow.3 This can result in pelvic venous hypertension, which may obstruct outflow at the renal vein anastomosis.
We report the cases of two kidney transplant patients who currently have well-functioning allografts but whose femoral AV grafts required ligation at different times during the patients' postoperative recovery. As a result of these cases, we recommend either contralateral placement of the allograft or that intraoperative ultrasonography be used to assess flow dynamics at the AV graft, iliac vessels, and distal inferior vena cava.
Case 1—A 56-year-old man with end-stage renal disease secondary to hypertension received hemodialysis up until he underwent a cadaveric kidney transplant. The patient had multiple hemodialysis accesses placed in the past, was taking warfarin, and had a patent right femoral loop AV graft. His allograft was inserted in the right iliac fossa. Immediate postoperative ultrasonography of the allograft demonstrated no diastolic arterial flow (Figure A); however, compression of the AV graft restored the flow (Figure B). The patient was urgently returned to the operating room for ligation of his AV graft under local anesthesia. Follow-up ultrasonography demonstrated excellent flows.
Case 2—A 45-year-old woman with end-stage renal disease resulting from systemic lupus erythematosus came in for kidney retransplantation after the first transplanted kidney failed, necessitating its removal. The patient had been dialyzed via a right femoral AV graft, and her kidney was placed on the right side. At the conclusion of her transplant, the allograft was noted to have poor color, and the AV graft was preemptively ligated.
A literature review identified only five cases similar to the ones reported in this paper.4-6 Two cases involved children and detailed similar experiences with decreased allograft function secondary to steal syndrome from a femoral AV graft.4 This complication was documented by digital subtraction angiography, and AV graft ligation was undertaken, which improved flows. One of the patients in these cases had an allograft placed ipsilateral to the femoral access site, like the patients in this paper, whereas the other patient had a contralateral placement. The conclusion that even a remote AV fistula can cause steal syndrome is supported by a case in which a traumatic groin AV fistula was ligated, resulting in an improvement of allograft dysfunction and resolution of ischemic symptoms in the upper extremity.5 The other three cases involved patients whose allografts were placed ipsilateral to the femoral access site.6 All of these transplants functioned well postoperatively. The contralateral site for these patients had been used for a previous kidney transplant and contained the failed allograft, necessitating ipsilateral positioning. Preoperatively, the local hemodynamics was studied extensively with venography and pressure measurements to rule out stenosis or venous hypertension.
As compared with the other reported cases, we did not determine whether the arterial or venous end of the graft created the problem because steal syndrome or venous hypertension would present the same way and have identical solutions. The positioning of the transplant kidney in our patients and the documented improvement subsequent to ligation of the AV graft reflects the allograft's functional dependence on the local hemodynamics.
The loss of AV access in the immediate posttransplant setting is most dangerous in the event of delayed graft function. A patient whose allograft does not work immediately could require postoperative hemodialysis but would then have no dialysis access site. At even higher risk are patients whose graft function never recovers or later fails and who therefore require new, ongoing hemodialysis access. As these scenarios demonstrate, the decision to ligate a femoral AV graft must not be taken lightly.
A full preoperative assessment could minimize the possibility of precluding access for future hemodialysis. As has been done previously, each patient would be subjected to the risks of obtaining contrast venography and pressure measurements. Alternatively, it is possible to use duplex ultrasonography to evaluate patency and flow dynamics at the AV graft, iliac vessels, and distal inferior vena cava. While duplex ultrasonography would yield no absolute pressure data, it is noninvasive and can be done preoperatively or during surgery.
In our experience, the presence of a femoral AV graft may complicate ipsilateral positioning of the kidney transplant. In such cases, we recommend either contralateral placement of the allograft or performing a detailed preoperative workup. Although some literature advises against contralateral placement, this placement appears less troublesome than ipsilateral placement. If the patient's previous surgical interventions necessitate or favor ipsilateral placement, full preoperative evaluation of the local hemodynamics is recommended. In either circumstance, intraoperative duplex ultrasonography would best assess flow dynamics after revascularization of the allograft.
The authors have no relationship with any commercial entity that might represent a conflict of interest with the content of this article and attest that the data meet the requirements for informed consent and for the Institutional Review Boards.