Over-the-Wire Inversion Saphenectomy: A Simple, Minimally Invasive Vein Harvesting Technique for Arterial Bypass

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1 394 J ENDOVASC THER CLINICAL INVESTIGATION Over-the-Wire Inversion Saphenectomy: A Simple, Minimally Invasive Vein Harvesting Technique for Arterial Bypass Bradley B. Hill, MD 1,2 ; Rishad M. Faruqi, MD 2 ; Frank R. Arko, MD 1 ; Christopher K. Zarins, MD 1 ; and Thomas J. Fogarty, MD 1 1 Stanford University Medical Center, Stanford, California, USA. 2 Kaiser Permanente Medical Center, Santa Clara, California, USA. Purpose: To examine the feasibility and clinical outcome of a novel, minimally invasive technique for harvesting the great saphenous vein (GSV) for use in peripheral arterial bypass surgery. Methods: Between May 2001 through March 2003, 27 patients (15 men; mean age 7110 years) underwent extremity bypass procedures for limb salvage (88%) or disabling claudication (12%) using the inversion technique to harvest the GSV. The veins were turned inside out using a unique catheter and guidewire system. With the endothelial surface exposed, valve leaflets were excised, and adherent thrombus was washed away. Veins were inverted again to turn the endothelial surface back inside the lumen for use as a bypass conduit. Results: Inversion vein harvesting and arterial bypass were completed in 24 (89%) of 27 patients; 2 patients were treated with synthetic grafts because of small GSVs. Another patient was found after vein harvesting to have inadequate arterial outflow despite a good quality conduit. The average vein length was 4510 cm; a mean 41 incisions were made, including those for arterial exposure. Incisions made to divide vein tributaries averaged 2 cm in length. Duration of vein harvesting was 25 minutes (range 5 80). Wound complications were minor (2 hematomas, 2 cases of erythema, 2 seromas). Of 6 grafts that occluded after 30 days, 5 involved small-diameter vein grafts (3.5 mm). At a mean 12 months, primary and assisted primary graft patency rates were 88% (14/16) and 94% (15/ 16), respectively, for grafts with minimum diameters 4 mm versus 38% (3/8) primary patency for veins 4 mm(n8, p0.001). The limb salvage rate was 92% (22/24). Conclusions: Over-the-wire inversion saphenectomy is a simple and reliable minimally invasive technique for arterial bypass. Incisions are small and cosmetically superior to those of the traditional long incision method. One-year follow-up suggests that grafts harvested by inversion technique have excellent durability when the minimum vein diameter is 4 mm, as determined by preoperative vein mapping. J Endovasc Ther Key words: bypass grafting, great saphenous vein, saphenectomy, vein inversion technique Prospective studies have demonstrated advantages of endoscopic vein harvesting over traditional open vein harvesting. Benefits include lower wound morbidity, faster recovery, and better patient satisfaction compared to the open technique. 1 4 Histological studies have shown that endoscopic harvesting causes no more damage than open retrieval. 5,6 De- Drs. Hill and Fogarty have a financial interest in Grove Medical, Inc., which possesses intellectual property relevant to vein inversion technology. Address for correspondence and reprints: Bradley B. Hill, MD, Division of Vascular Surgery, H3639, 300 Pasteur Drive, Stanford University Medical Center, Stanford, CA USA. Fax: ; bhill@stanford.edu 2005 by the INTERNATIONAL SOCIETY OF ENDOVASCULAR SPECIALISTS Available at

2 J ENDOVASC THER OVER-THE-WIRE INVERSION SAPHENECTOMY 395 spite the favorable study results, endoscopic methods have not gained widespread acceptance among vascular surgery specialists because many consider the endoscopic systems somewhat cumbersome. Moreover, there is a requirement for additional instrumentation and setup. An inversion method has been described for removing the saphenous vein for treating patients with venous reflux disease. 7 Experience with this inversion technique led to the development of a new concept and minimally invasive system for harvesting vein grafts that does not require endoscopy or fluoroscopic visualization. By using a coaxial guidewire and catheter system, the great saphenous vein (GSV) can be completely removed from its bed in a precise and controlled fashion. The inversion method, in contradistinction to vein stripping, does not involve avulsion of the vein from its bed without surgically dividing its tributaries. The technique also provides opportunity for the surgeon to excise valve leaflets under direct vision. The vein can then be turned right side in again for use as an arterial bypass graft. METHODS Study Design and Patient Sample With the approval of the institutional review board, a retrospective review was conducted to identify all patients scheduled for inversion vein harvesting during peripheral arterial bypass procedures from May 2001 through March Data were gathered on patient demographics, diagnosis, vein diameter and length used for the grafts, number of incisions required, surgery time, graft patency at last follow-up, complications, and pre and postoperative ankle-brachial indices (ABIs). The review found 27 patients (15 men; mean age 71 years, range 50 85) who were scheduled for over-the-wire inversion vein harvesting during an extremity bypass procedure. Twenty-six patients had lower extremity bypasses for limb salvage (n22) and disabling claudication (n4). One patient underwent axillobrachial bypass for treatment of a complex traumatic axillary pseudoaneurysm. Whenever possible, candidates for extremity arterial bypass had preoperative vein mapping by duplex ultrasonography to measure the vein diameter from the ankle to the saphenofemoral junction (SFJ) and assess wall thickness and the presence/absence of varicosity. Technique At the time of surgery, proximal and distal arterial exposures were performed in preparation for bypass. At the appropriate location, and depending on the length of bypass graft needed, the distal GSV was exposed and ligated through a short skin incision. The proximal GSV was exposed through a groin incision and mobilized to the SFJ. A short transverse venotomy was made in the GSV at the distal incision, just proximal to the ligature, and a inch straight stiff Glidewire (Terumo Medical Corporation, Somerset, NJ, USA) was introduced into the vein and advanced proximally to the SFJ, where it was palpable through the vein wall. The wire was pulled back enough to allow clamping of the SFJ and division of the GSV. Bleeding from the unclamped side of the vein was controlled with a Silastic vessel loop, and the proximal GSV stump was oversewn. A vein extraction catheter (Grove Medical, Inc., Portola Valley, CA, USA) was advanced over the wire through the proximal end of the vein to the distal end, where the vein was then transected and suture ligated to the shaft of the catheter (Fig. 1). The vein was removed by the inversion technique (Fig. 2), with steady but gentle force on the catheter in a cephalad direction. Small tributaries were avulsed without damaging the GSV, but larger tributaries that created sufficient resistance were exposed, clipped, and divided through short counterincisions. Extreme care was taken to avoid unnecessary contact with the endothelial surface of the vein during all steps of the procedure. After removing the vein, it was placed in a shallow pan that contained a heparin-saline solution; the valve leaflets were excised using Potts scissors under direct vision with loupe magnification. Adherent thrombus was gently washed from the endothelial surface. The vein was then inverted again to turn the en-

3 396 OVER-THE-WIRE INVERSION SAPHENECTOMY J ENDOVASC THER dothelial surface back inside the lumen. This was done by clamping the proximal end of the catheter with a Kelly clamp to functionally fuse it to the guidewire. The vein was easily inverted by gently pulling the distal end of the wire while steadily grasping the vein near the conical tip of the catheter with the palmar surface of the hand. The vein was prepared in a routine fashion for arterial bypass by ligating or oversewing small tributaries, as indicated, with 7 0 polypropylene suture. Follow-up and Statistical Analysis Figure 1The conical-tip and smooth-tapered designs of the vein extraction catheters. Eyelets (arrows) located near the tip allow suture fixation of the vein to the catheter shaft. Patients were followed after hospital discharge by duplex ultrasonography at 1, 6, 12, and 18 months postoperatively, then yearly thereafter unless a problem was detected. Studies included measurement of peak systolic velocity at the inflow artery, proximal anastomosis, multiple sites along the graft Figure 2Steps of vein inversion technique. (A) The vein inversion is begun by suture fixation of the vein to the catheter tip. (B) Initial vein inversion is started by pulling the catheter in a cephalad direction. (C) The location of vein tributaries is determined by force feedback while pulling on the catheter. The skin dimple, which is created by traction on the tributary and surrounding tissues, marks the site for a short counterincision through which the tributary can be clipped or ligated and then divided. (D) Continuation of vein inversion after division of the tributary: note that the infolding edge of the vein travels at half the rate of the catheter during the inversion process. When the catheter tip emerges from the proximal end of the vein, the vein is inverted along half its length.

4 J ENDOVASC THER OVER-THE-WIRE INVERSION SAPHENECTOMY 397 Figure 2 continued (E) Once the vein has been fully inverted, the endothelial surface is exposed. The vein is outside the patient at this point, but it is still attached to the catheter tip. The guidewire is left in place inside both the catheter and vein, which allows valve leaflet excision under direct vision and removal of adherent thrombus that is frequently present after vein harvesting whether by open surgical or inversion technique. (F) The vein is reinverted by clamping the end of the catheter opposite the vein suture point, which will functionally fuse the catheter and guidewire together. The vein is gently reinverted starting at the suture point, and the remainder of the vein will follow over the wire and catheter with only minimal force required. The vein is then prepared in a routine fashion for use as a bypass conduit. (including the highest velocity detected), the distal anastomosis, and the outflow artery. ABIs were calculated for all lower extremities. Statistical analysis of patency outcomes was performed by the Fisher exact test with 2-tailed distribution. Statistical significance was defined at p0.05. RESULTS The vein inversion technique was applied successfully in 24 (89%) of 27 bypass procedures, including the axillobrachial bypass and a femoral-peroneal bypass that used a composite vein graft constructed from the right arm basilic and cephalic veins, both harvested by the inversion technique. Twenty-two patients had lower extremity bypasses utilizing autologous GSV (10 above knee and 12 below knee). GSV lengths averaged 4510 cm; a mean 41 incisions were made for vein harvest, including the proximal and distal incisions for arterial exposure. Incisions made to assist only in vein harvesting averaged 2 cm in length. On average, 8 valve leaflets were excised from 4 valves per patient. The mean duration of vein harvest was 25 minutes (range 5 80 minutes). Most bypasses (21/24) were performed with the vein in a nonreversed orientation. One patient was found after vein harvesting to have severe disease progression in her single tibial outflow vessel; bypass grafting was not successful because of inadequate arterial outflow despite a good quality conduit. Of 2 cases in which the inversion technique was not applied, 1 patient was found to have a vein 3 mm in diameter throughout most of its length at the time of operation. The other patient had diffuse sclerosis of the GSV. Both of these patients were treated using polytetrafluoroethylene grafts. For the patients who had initially successful lower extremity bypass grafts, the mean ABI was preoperatively and postoperatively. Wound complications associated with the short saphenectomy incisions were minor (2 hematomas, 2 cases of erythema, 2 seromas) and did not require hospital readmission or reoperation, although 1 patient had percutaneous drainage of an infected distal thigh lymphocele 7 months postoperatively. One patient with severe cardiomyopathy and a gangrenous forefoot died before hospital discharge from a malignant arrhythmia. One patient died at home on postoperative day 31 from bleeding at the distal arterial exposure incision; autopsy findings were consistent with a deep soft tissue infection and false aneurysm. Three other patients died after hospital discharge at 2, 5, and 6 months postoperatively (1 from malignancy and 2 from cardiopulmonary-related disease). The mean follow-up for the 24 patients who had successful bypass was months

5 398 OVER-THE-WIRE INVERSION SAPHENECTOMY J ENDOVASC THER to a primary patency of 38% (3/8) for veins 4 mm (n8, p0.001). The limb salvage rate was 92% (22/24). Figure 3Angiogram of inverted vein graft shows a patent superficial femoral artery (SFA) to popliteal saphenous vein graft 27 months after bypass grafting. The vein graft (between arrows) appears normal throughout its length. A stenosis (top arrow) at the distal SFA is noted just above the proximal anastomosis. The stenosis was treated successfully by balloon angioplasty. (range ). Six grafts occluded at 2, 3, 4, 6, 10, and 15 months. Five of the occluded grafts were small, with minimum diameters 3.5 mm documented on the preoperative duplex or at the time of bypass. The patient with the composite basilic and cephalic vein graft had successful percutaneous balloon angioplasty of 2 focal areas of graft stenosis during the 9th postoperative month. Another patient had balloon angioplasty 27 months after operation for a distal superficial femoral artery stenosis that was proximal to her graft (Fig. 3). At a mean 12-month follow-up, primary graft patency was 88% (14/16) and assisted primary patency was 94% (15/16) for grafts with minimum diameters 4 mm, as opposed DISCUSSION Our 1-year outcome for grafts 4 mmindiameter harvested using the inversion technique was excellent, as was overall limb salvage despite the lower patency in small grafts. In this simple and easy-to-use harvesting technique, the wire serves as a rail over which the vein is inverted and removed; it also helps stabilize the vein during inversion. Tributaries that are large enough to potentially damage the vein generate force feedback that tells the operator to stop pulling the inversion catheter. Traction on the tributary causes the skin to dimple, which marks the site for a short skin incision through which the operator palpates the guidewire with a fingertip and identifies the tributary to be divided. Unlike in situ bypass techniques, angiography is not required for locating patent tributaries and arteriovenous fistulas. The inversion technique is fast by comparison to the time it takes to close the long incisions typically made for conventional vein harvesting. Compared to other minimally invasive vein harvesting techniques, the inversion method assures a valveless conduit without adherent endoluminal thrombus and needs no endoscopic setup or CO 2 insufflation. We tried using endoscopy for the inversion technique early on but abandoned it because the imaging increased the complexity of the procedure and was not helpful. Vein mapping is important for preoperative planning, especially for bypass surgery in the peripheral vasculature where long conduits are needed, as opposed to coronary bypass that usually requires shorter graft segments. We currently do not use the inversion technique in veins with diameters 4 mm because of the risk of injuring the smaller veins. Future advances in catheter technology and techniques may eventually make inversion harvesting of smaller veins possible with acceptable long-term patency. Exposing the endothelium to the outside of the vein is not a new concept in bypass grafting. Vein patches by their very nature have

6 J ENDOVASC THER OVER-THE-WIRE INVERSION SAPHENECTOMY 399 Figure 4(A) A control specimen harvested by open surgical technique measures 4 to 5 mm in diameter; hematoxylin and eosin (H&E, original magnification 100) and factor VIII (original magnification 100) staining demonstrate preservation of vein wall architecture and presence of endothelial cells. (B) Vein specimen harvested by inversion technique shows gross and histological characteristics similar to that of the open surgical specimen. exposed endothelium from the time they are prepared until they are sewn into an artery. Double thickness inverted vein patches, which have been used for years for patching carotid arteriotomies without known complications, were devised to lessen the chance of patch rupture. After we evolved this inversion technique, we compared histological samples of 4-mm-diameter veins that were excised by inversion or conventional techniques; there were no significant differences in vein integrity (Fig. 4). The inversion technique has also been adapted to other surgical procedures, notably, the treatment of venous reflux disease. The less invasive nature of vein excision produces less soft tissue trauma and bleeding. The wire provides access in case the vein is transected in the mid thigh, and since the wire is still intraluminal, the procedure can be converted to a conventional procedure using a vein stripper. Another application of the over-the-wire technique is for brachiobasilic arteriovenous fistula procedures in the upper arm. In these cases, the inversion is performed by pushing the vein inside itself over the wire using a push catheter instead of the pull catheter technique used with harvesting of the GSV. Inversion saphenectomy also provides an opportunity for surgeons to further develop the endovascular skills that are becoming increasingly important within the vascular surgeon s scope of practice. As can be seen from our early experience with this technique, which included our learning curve, the overthe-wire approach to vein harvesting is easily learned. For the beginner, the inversion method can be used for removing the GSV for treating venous insufficiency. In terms of durability, we suspect myointimal hyperplasia as the primary cause of the graft failure we encountered in the 5 patients with small veins; however, poor distal arterial outflow may have also contributed because all 5 patients had tibial arterial disease. The graft failure that occurred at 10 months was in a 50-cm graft that had a minimum diameter of 4 mm. In this patient, inadequate distal outflow is suspected because the distal anastomosis was to an anterior tibial artery that reconstituted just above the ankle. In a surveillance duplex study at 6 weeks postoperatively, the graft was widely patent without stenosis, but peak systolic velocities were 0.6 m/s in the proximal portion of the graft. Conclusions Over-the-wire inversion saphenectomy is a simple and reliable minimally invasive technique for arterial bypass. Incisions are small and cosmetically superior to those of the traditional long incision method. One-year follow-up suggests that grafts harvested by in-

7 400 OVER-THE-WIRE INVERSION SAPHENECTOMY J ENDOVASC THER version technique have excellent durability when the minimum vein diameter is 4 mm, as determined by preoperative vein mapping. A larger clinical experience with inversion saphenectomy, including other clinical sites, is needed for validation of these conclusions. Currently, instrumentation designed specifically for the vein inversion procedure is not commercially available, and caution should be exercised when using the technique. REFERENCES 1. Allen KB, Heimansohn DA, Robison RJ, et al. Risk factors for leg wound complications following endoscopic versus traditional saphenous vein harvesting. Heart Surg Forum. 2000; 3: Schurr UP, Lachat ML, Reuthebuch O, et al. Endoscopic saphenous vein harvesting for CABG a randomized, prospective trial. Thorac Cardiovasc Surg. 2002;50: Felisky CD, Paull DL, Hill ME, et al. Endoscopic greater saphenous vein harvesting reduces the morbidity of coronary artery bypass surgery. Am J Surg. 2002;183: Bitondo JM, Daggett WM, Torchiana DF, et al. Endoscopic versus open saphenous vein harvest: a comparison of postoperative wound complications. Ann Thorac Surg. 2002;73: Meyer DM, Rogers TE, Jessen ME, et al. Histologic evidence of the safety of endoscopic saphenous vein graft preparation. Ann Thorac Surg. 2000;70: Lancey RA, Cuenoud H, Nunnari JJ. Scanning electron microscopic analysis of endoscopic versus open vein harvesting techniques. J Cardiovasc Surg (Torino). 2001;42: Goren G, Yellin AE. Invaginated axial saphenectomy by a semirigid stripper: perforate-invaginate stripping. J Vasc Surg. 1994;20: