Vein patches still work, but are they better in 2023 than in 2003?

One of the conclusions of the BEST-CLI trial (ref 1) was that of equivalency between alternate bypass conduits and interventions when a single saphenous vein is not available. I recently contacted Dr. Matt Menard to see if there had been subgroup analysis of these bypasses which represents a heterogeneous group of conduits including PTFE, PTFE with vein patch, spliced vein, composite vein, and even possibly allograft. The results from the abstract were intriguing -“83 of 194 patients (42.8%) in the surgical group and in 95 of 199 patients (47.7%) in the endovascular group (hazard ratio, 0.79; 95% CI, 0.58 to 1.06; P = 0.12) after a median follow-up of 1.6 years” with the primary MALE endpoint. If this was a football game, there would be a video review of the call. And they are looking at this, I was assured by Matt, but we would all have to wait for this year’s SVS VAM. Dr. Matt Menard is coming to speak at our 12th Annual Vascular Disease Update (link) which I highly encourage you to register and attend (addendum).

The Cohort 1 from BEST-CLI is an illustration of the vascular surgeons’ LIMA to LAD. It’s something we already knew from years of experience, but laid out in level 1 data (below).

The BEST-CLI paper is short on detail about cohort 2. This is where a lot of clinical decisions get made, and I suspect the vast majority of patients are getting interventions because fewer surgeons are facile with leg bypasses and vein patches.

Why the vein patch? While not a panacea for the lack of vein, from its inception, it has proved a worthy adjunct in limb salvage. Decades before endovascular therapies showed good limb salvage with modest to poor patency rates, Dr. Frank Veith showed that infrageniculate PTFE bypasses showed good limb salvage with poor patency (reference 2). Vein patches, such as the Taylor patch illustrated at the top, showed good patencies (reference 3) in an era where DOACS, DAPT, and statins were not available.

Why a patch works is debated. Some feel it is the modification of the end to side anastomosis that creates an optimal shape for containing turbulence which leads to intimal hyperplasia. This was the concept behind the Distaflo graft which I tried but have abandoned for not improving patency in my personal experience.

The best explanation of why vein cuffs work is from an animal study from Vienna. Intimal hyperplasia is best explained as a foreign body reaction and the reaction is worse with a true foreign body than with autologous materials. A simple anastomosis with PTFE to tibial artery creates a ring of hyperplasia. Vein patching moves this severe foreign body reaction off of the artery, leaving a gentler vein to artery reaction to occur on the outflow (reference 4).

My final point is that these surgical papers used to be the mainstay of podium presentation in the 90’s and ’00’s, but are now infrequent as the bulk of the time at these meetings is devoted to gadgets which almost always involves purchasing a box and contracting for disposables (the printer and ink business model). I am going to review our institutional results of these PTFE bypasses, and hope to see more from other groups. I look forward to the BEST-CLI papers to come, and other trials.

References

1. Farber A, Menard MT, et al. BEST-CLI Investigators. Surgery or Endovascular Therapy for Chronic Limb-Threatening Ischemia. N Engl J Med. 2022 Dec 22;387(25):2305-2316. doi: 10.1056/NEJMoa2207899. Epub 2022 Nov 7. PMID: 36342173.
2. Veith FJ, Gupta SK, Ascer E, White-Flores S, Samson RH, Scher LA, Towne JB, Bernhard VM, Bonier P, Flinn WR, et al. Six-year prospective multicenter randomized comparison of autologous saphenous vein and expanded polytetrafluoroethylene grafts in infrainguinal arterial reconstructions. J Vasc Surg. 1986 Jan;3(1):104-14. doi: 10.1067/mva.1986.avs0030104. PMID: 3510323.
3. Taylor RS, Loh A, McFarland RJ, Cox M, Chester JF. Improved technique for polytetrafluoroethylene bypass grafting: long-term results using anastomotic vein patches. Br J Surg. 1992 Apr;79(4):348-54. doi: 10.1002/bjs.1800790424. PMID: 1576506.
4. Trubel W, Schima H, Czerny M, Perktold K, Schimek MG, Polterauer P. Experimental comparison of four methods of end-to-side anastomosis with expanded polytetrafluoroethylene. Br J Surg. 2004 Feb;91(2):159-67. doi: 10.1002/bjs.4388. PMID: 14760662.

Addendum

The Annual Vascular Update at University Hospital has something for everyone, including a presentation on IRAD by Dr. Santi Trimarchi, and BEST-CLI by Dr. Matthew Menard. Local faculty from Cleveland are also featured in a broad review of vascular medicine and surgery chaired by Drs. Mehdi Shishehbor, Heather Gornik, and our chair in vascular surgery, Dr. Jae Sung Cho. Link. I will be presenting on neurovascular compression syndromes and renal failure/heart failure.