A 71-year-old female on hemodialysis three times a week complained of increased bleeding lasting more than 15 minutes from her access, which is in her left upper extremity. She denies any other complaints.For the past four weeks, she has noticed progressively increased bleeding time after her dialysis needles are removed. This access has never been clotted. She does not take any medications, such as plavix, aspirin, or coumadin. Her KT/V decreased from 1.8 to 1.2 and her access blood flow has decreased by 25 % over the past five weeks.
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Question 1 Answer: B
The basilic vein is a large caliber vein (usually close to twice the size of a cephalic vein in diameter) that is located deep in medial aspect of the upper arm. Therefore, a longitudinal surgical incision is made on the skin (which is visible in figure 1) to bring this vein to the surface of the skin in the first stage of the surgical procedure. This makes the basilic vein grow in caliber.
In the second stage of the surgical procedure, this vein is swung across and placed in a tunnel in the lateral part of the arm to facilitate easy access so the dialysis nurse is able to cannulate the fistula. The correct answer is B because you see the classic longitudinal incision in the medial aspect of the arm. The cephalic vein is in the lateral aspect of the arm. The surgical incision usually is made across the elbow, so choice A is not correct.
Choices C and D are not correct because loop grafts or axillary grafts typically do not have a single longitudinal medial surgical incision. More commonly, grafts have two separate surgical incisions or scars, the first one to create the anastmosis between the graft and the vein and the second incision or scar is to create an anastmosis between the graft and the artery.
Question 2 Answer: D
As explained above, the brachial artery-basilic vein fistula is created with superficialization of the basilic vein (commonly referred to as “first stage”). Many surgeons elect to do the “second stage” of the fistula after a variable interval of 3-10 weeks that allows the basilic vein to enlarge and become less susceptible to injury, facilitating easy mobilization of this vein.
In the “second stage,” the basilic vein is swung across from its native medial location to a more lateral location and placed in a tunnel. This segment of the basilic vein, which is swung across, has a certain degree of angulation and classically develops stenosis in this segment. This stenosis (as seen in figure 2) is called “swing segment stenosis,” so the correct answer is D.
Arterial inflow is not shown in figure 2, so choice C is not correct. The basilic vein fistula does not drain into the cephalic arch and cephalic arch stenosis is not usually associated with a brachial artery-basilic vein fistula. Thus, choice B also is not correct. Figure 2 clearly depicts the swing segment for the basilic vein, which is stenosed.
Ramanath Dukkipati, MD, and Rajiv Dhamija, MD, prepared the case. Dr. Dukkipati is Assistant Professor of Medicine and Medical Director of Interventional Nephrology at the Harbor -UCLA Medical Center and David Geffen School of Medicine at the University of California in Los Angeles.
Dr. Dhamija is Assistant Professor of Medicine at Western University of Medical Sciences in Pomona, Calif., and an interventional nephrologist at Rancho Los Amigos National Rehabilitation Center, Downey, Calif.