That was my response when my vascular surgery mentor from med school told me about her plan.
“Yap, I’ve done it before. It’s the only viable option we have left.
The patient is a Caucasian female in her late 50s. She has extensive aorto-iliac occlusive disease, and status post past aorto-bifem bypasses that failed and salvaged with stents and fem-fem. The fem-fem then failed and more stents were placed. She is now presenting with postprandial abdominal pain, weight loss and food fear, a classic triad of chronic mesenteric ischemia, as well as right sided lower extremity rest pain. Her aorta had extensive calcification throughout, including the supraceliac region, and there was no inflow site adequate for an aorto-mesenteric bypass. Fortunately, extra-anatomical bypass was never done for her in the past. Duplex revealed retrograde flow at common hepatic artery and CT revealed a patent hepatic artery despite severe stenosis at other splanchnic vessels. CT with runoff showed a patent right profunda artery with distal collateralization.
So the outline of bypass was something like this:
In the end, the patient gained palpable right lower extremity pulses and audible doppler signal throughout the branches of her SMA.
Some takeaways and pointers from this procedures are listed below:
- Tunneling via midaxillary line if axillo-fem bypass only; tunneled deep to the pectoralis major and into the abdominal cavity under the costal margin if axillo-mesenteric bypass. In this case, the tunneling was via right midaxillary line but one of the bifurcated limb of graft was swung over the costal margin into the peritoneal cavity.
- Third part of axillary artery after emerging from pec minor was used for inflow. This part of axillary artery gives simpler exposure (need to split pec minor/major if more proximal part is used).
- Ringed PTFE graft for simple procedure (no need for vein harvest) and it is protected from kinking compared to GSV. However, if bowel were infarcted then GSV preferred due to less likelihood of graft infection.
- Greater omentum was first sutured around the entry point of the graft into the abdomen and then invaginated over the main body of the graft using interrupted Vicryl suture to exclude it from peritoneal cavity.
- Interposing vein collar/cuff was not used, but it might have been a good idea…
- The smaller size of graft is preferred (8mm). A larger diameter will result in slower velocity, increasing the buildup of pseudointima.
- Endarterectomy of visceral arterial ostium not possible due to no clamping site at supraceliac aorta due to calcification. However, this might be an option if clamp site as present (or do a thoraco-hepatic-profunda bypass)
- Endovascular intervention was out in this case due to prior aorto-bifem (thrombosed proximal CFA) and supraceliac calcification (rendering brachial approach difficult).
- Axillary inflow might just serve as a bridging procedure to allow temporary clinical stabilization and definitive reconstruction at a later date. However, in this patient it will likely serve as definitive repair.
- Renal arteries were patent in this patient, so even though aortic plaque usually originates at the infrarenal aorta, this patient just had ostial lesions at the visceral branches and atherosclerosis of supra celiac region, which represent a rarer progression of aortic atherosclerosis.
If one knows what she is doing, one can achieve great things in what seems to first timers as really funky ways.