Repair of type IV thoracoabdominal aneurysm with a combined endovascular and surgical approach

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1 Repair of type IV thoracoabdominal aneurysm with a combined endovascular and surgical approach William J. Quiñones-Baldrich, MD, Thomas F. Panetta, MD, Candace L. Vescera, RN, and Vikram S. Kashyap, MD, Los Angeles, Calif We report an unusual case of type IV thoracoabdominal aneurysm (TAA) with superior mesenteric artery (SMA), celiac artery, and bilateral renal artery aneurysms in a patient who underwent an earlier repair of two infrarenal abdominal aortic aneurysm (AAA) ruptures. Because of the presence of the visceral artery aneurysms and the earlier operation through the retroperitoneum, standard surgical treatment via a retroperitoneal approach with an inclusion grafting technique was considered difficult. A combined surgical approach achieving retrograde perfusion of all four visceral vessels and endovascular grafting allowing exclusion of the TAA was accomplished. Complete exclusion of the aneurysm and normal perfusion of the patient s viscera was documented by means of follow-up examinations at 3 and 6 months. The repair of a type IV TAA with a combined endovascular and surgical approach (CESA) allowed us to manage both the aortic and visceral aneurysms without thoracotomy or re-do retroperitoneal exposure and minimized visceral ischemia time. If the durability of this approach is confirmed, it may represent an attractive alternative in patients with aneurysmal involvement of the visceral segment of the aorta. (J Vasc Surg 1999;30: ) Surgical intervention for type IV thoracoabdominal aneurysm (TAA) has traditionally involved a retroperitoneal exposure and in-line grafting by means of the inclusion patch technique for visceral revascularization. The left renal artery frequently requires either a separate bypass grafting procedure or reimplantation with a Carrel patch. Alternatively, a medial visceral rotation technique can be used when the proximal neck of the aneurysm is in the most distal descending thoracic or supraceliac aorta. Results of these approaches have been satisfactory; however, morbidity can reach 10% to 20%, 1 with the most common complications resulting in renal failure, procedural bleeding, and/or spinal cord ischemia. We present a case of a type IV TAA that was complicated by the presence of large superior mesenteric artery (SMA), celiac artery, and bilateral renal artery aneurysms. In addition, the patient had twice survived rupture of an infrarenal abdominal From the Department of Vascular Surgery, UCLA Center for the Health Sciences and the Department of Vascular Surgery, State University of New York (Dr Panetta). Reprint requests: William J. Quiñones-Baldrich, MD, Vascular Surgery, UCLA Center for the Health Sciences, Le Conte Ave, # CHS, Los Angeles, CA Copyright 1999 by The Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter /99/$ /4/99316 aortic aneurysm (AAA), with earlier repairs by means of both the transperitoneal and retroperitoneal approach. At the time of the second AAA repair, the diagnosis of a suprarenal aneurysm was entertained and was confirmed postoperatively by means of a computed tomography (CT) scan. The combined presence of a type IV TAA and large aneurysms at the origin of each of the visceral vessels in a reoperative field would make standard surgical repair formidable. The presence of the visceral aneurysms precluded the inclusion technique, and thus, a combined bypass grafting and replacement technique would most likely be required. The availability of endovascular grafting at our institution allowed us to use a combined endovascular and surgical approach (CESA) for the management of this complex lesion. To our knowledge, this is the first reported case of TAA repair using a CESA. CASE REPORT Mr P.L., a 62-year-old man, was referred for evaluation of a type IV TAA after surviving two previous ruptures of his infrarenal aorta. In February 1997, he had undergone urgent repair of a ruptured infrarenal AAA with a Dacron tube prosthesis through a midline transperitoneal approach. In October 1997, he had progressively increasing back and abdominal pain and was found to have a contained rupture below the site of his earlier repair. The findings of a CT scan at this time were consistent with a 555

2 556 Quiñones-Baldrich et al September 1999 Fig 1. Preoperative computed tomography scan revealing an aneurysmal visceral aorta and superior mesenteric artery. The superior mesenteric artery aneurysm extended distally 5 cm from its origin. Fig 3. Preoperative lateral angiogram showing a celiac artery aneurysm measuring 2 cm and superior mesenteric artery aneurysm measuring 2.2 cm. Fig 2. Preoperative antero-posterior angiogram revealing the thoracoabdominal aneurysm, starting in the distal thoracic aorta and involving the visceral aorta. ruptured aortic aneurysm distal to the previous repair and proximal to the aortic bifurcation. Based on the operative note, the impression of the operating surgeon was that this process was most likely related to residual aneurysm and not an anastomotic process. Emergency repair was undertaken, with a bifurcated prosthesis placed distal to the tube prosthesis by means of a retroperitoneal approach. Both a proximal aortic aneurysm in the visceral aortic area and a left renal artery aneurysm were found, but not repaired because the operation was performed in emergency conditions. After recovery from this second operation, the patient was referred to UCLA for evaluation of his TAA and the renal and visceral aneurysms. His medical history was significant for hypertension and past history of smoking. There was no conclusive family history of aneurysmal disease. On examination, a right popliteal aneurysm was found. Aneurysmosis with two sequential left superficial femoral artery (SFA) aneurysms and a right popliteal artery aneurysm was revealed by means of duplex imaging. Aneurysmal dilatation of the aorta at the diaphragm measuring 5 cm at its maximum diameter, a celiac artery

3 Volume 30, Number 3 Quiñones-Baldrich et al 557 Fig 4. The Corvita endovascular graft deployed in the thoracic aorta. Another Corvita graft was deployed in the abdominal aorta, with overlapping of the two grafts in the midportion. This completely excluded the thoracoabdominal aneurysm, with no evidence of perigraft leak. Fig 5. Retrograde visceral bypass grafts. A bifurcated Dacron graft was used for bilateral renal artery bypass grafting, with the right iliac limb (of a previous aortic graft) serving as the donor vessel. Another Dacron tube graft was sewn on to the hood of the bifurcated graft. This was brought along the leaves of the base of the mesentery for anastomosis with the superior mesenteric artery at the level of the middle colic artery (side-to-side) and to the celiac axis (end-to-side) sequentially. aneurysm measuring 2.0 cm, a SMA aneurysm measuring 2.2 cm that extended from its origin for 5 cm, and bilateral renal artery aneurysms were shown by means of CT evaluation (Figs 1 through 3). Procedure. After approval by the Institutional Review Board at UCLA (the Medical Human Subjects Protection Committee) and informed consent, the patient was brought to the operating room on May 15, A midline laparotomy with extensive adhesiolysis was performed. The right limb of the previous bifurcated aortic graft was exposed and served as the donor vessel of inflow for the retrograde visceral bypass grafts and the access conduit for endovascular repair. Bilateral renal artery bypass grafting was accomplished by using a bifurcated 14- by 7- mm Hemashield (Meadox, Oakland, NJ) graft. An additional Hemashield 8-mm tube prosthesis was attached in an end-to-side fashion to the hood of the bifurcated graft. The latter was brought along the leaves of the base of the mesentery for anastomosis, with the SMA at the level of the middle colic artery (side-to-side) and to the celiac axis (end-to-side) sequentially. The placement of the graft from the SMA to the celiac required a retropancreatic tunnel. All the anastomoses were performed in normal arterial segments distal to any aneurysmal segments. The vessels were ligated proximal to each anastomosis. Performance of a visceral or renal anastomosis did not require interruption of aortic flow, thus decreasing the end-organ visceral ischemia time to a brief period (ie, 5 to 10 minutes) of clamping on the individual vessels. During dissection and mobilization of the left renal artery, a capsular tear of the spleen, which was not reparable and required a splenectomy, occurred. The Corvita Endoluminal Graft (CEG) Tubular Aortic Endoprosthesis (Schneider, Minneapolis, Minn) required an insertion conduit that was constructed on the right iliac limb of the existing bifurcated prosthesis and on the right axillary artery through a separate incision. The insertion conduit was constructed by using an 8-mm polytetrafluoroethylene graft with a hemostatic valve. The Corvita endovascular graft is a patented synthetic self-expanding braided metallic mesh tube lined with layers of Corethane (polycarbonate elastomer) micro fibers; it is FDA approved for investigational study. Details of the method for deploy-

4 558 Quiñones-Baldrich et al September 1999 Fig 6. Postoperative computed tomography scan at 3 months, revealing a well-seated endovascular graft without any perigraft leak, diminishing aneurysm sac size, and good perfusion of the viscera. ment of a Corvita graft are described elsewhere. 1 Because of the length of the entire aneurysm and the uni end-flare design of the Corvita graft, two endovascular prostheses were required. Essentially, each Corvita graft was placed into a long 7F sheath and deployed with a Terumo wire. The abdominal portion of the TAA was repaired by placement of the Corvita graft with an axillary approach. This was difficult because of the curvature of the thoracic aorta. The thoracic portion was repaired with placement of the Corvita graft by means of an iliac approach, with overlapping of the grafts in the midportion (Fig 4). Complete exclusion of the TAA, with excellent perfusion of the visceral and renal vessels and without evidence of endovascular or anastomotic leak, was revealed by means of the completion arteriogram (Fig 5). The patient did well postoperatively. A mild ileus that required nasogastric tube placement developed postoperatively. His creatinine level peaked at 1.6 mg/dl, but returned to 1.0 within 4 days. No evidence of spinal cord injury or mesenteric ischemia was revealed by means of the physical examination during the early postoperative period. On postoperative day 10, the patient was clinically stable and able to be discharged from the hospital. Two months after this initial procedure, he underwent repair of his right popliteal aneurysm without incident. No evidence of leak was revealed by means of postoperative CT (Fig 6) and Duplex scanning at 6 months. All bypass grafts remained patent, as documented by means of a 6-month spiral CT reconstruction (Fig 7). DISCUSSION Treatment of TAA remains a formidable surgical undertaking. Svensson s review of Crawford s massive experience with 1679 TAA repairs revealed spinal cord ischemia (16%) and renal failure (18%) to be the Fig 7. Spiral computed tomography scan 6 months after a combined endovascular and surgical approach of a type IV thoracoabdominal aneurysm was performed. All visceral bypass grafts are patent, with complete exclusion of the aneurysm. principal unsolved problems that complicate TAA repair. 2 Renal failure that necessitates dialysis is especially lethal, with a 60% or higher mortality rate. 3 This particular case presented significant challenge in its management, given the unusual combination of TAA, multiple visceral aneurysms, and reoperative fields. Both the transabdominal and retroperitoneal approach to the aorta had been used within the previous year for repair of ruptured AAAs. In addition, the significant aneurysmal dilatation of all four visceral branches emanating from the TAA would have required individual bypass grafts after in-line aortic replacement. Significant ischemic times would have been inevitable with such an approach. The treatment of this complex vascular case using CESA has several advantages. First, it was performed through a transabdominal approach that avoided a re-do retroperitoneal exposure, something that is most difficult within the first year after the original exposure. In addition, because aortic clamping was avoided, ischemia time to each of the visceral arteries was limited to the time of construction of the distal anastomosis, which in this case was not more than 15 minutes to each viscera. Ischemia to all four visceral branches at the same time was com-

5 Volume 30, Number 3 Quiñones-Baldrich et al 559 pletely avoided. Organ ischemia during TAA repair can lead to renal failure and coagulopathy (liver ischemia). Both of these complications are associated with increased mortality. 3,4 This combined approach presents potential disadvantages. The routing of the Dacron grafts in the intraperitoneal location must be minimized. This was avoided in both renal reconstructions by passing these grafts in the retroperitoneal position. For the SMA and celiac reconstructions, a single graft was passed through the leaves of the small bowel mesentery and in a retropancreatic location, thus avoiding direct contact with the intraperitoneal contents. The safety and durability of retrograde mesenteric bypass grafting versus antegrade bypass grafting remains a controversial topic. The advantages of the latter are a usually nondiseased, soft supraceliac aorta for proximal anastomosis and a shorter, more direct bypass grafting route. However, the retrograde approach is technically easier to perform, avoids supraceliac aortic clamping and thus lessens any intraoperative hemodynamic insult, and is not prone to stretching after the patient has recovered and is upright. In a review of 24 cases of chronic mesenteric ischemia, Moawad et al did not observe significant differences in long-term results among 17 patients who underwent antegrade bypass grafting procedures and seven patients who were revascularized with a retrograde conduit. The authors expressed their preference for the antegrade approach. 6 In contrast, Johnston et al noted a higher failure rate with the retrograde technique, reporting three thromboses in 16 cases, and none in five patients treated with the antegrade approach. 7 The small number of patients in the latter group, however, decreases the significance of this observation. A study by McMillan and colleagues 8 objectively documented graft patency postoperatively with Duplex scanning. In the McMillan study of 16 patients, patency rates for antegrade and retrograde bypass grafting procedures were similar. A recent review and critical analysis of the literature failed to identify a clearly superior technique for mesenteric revascularization and stated that the choice of operation must be individualized. 9 The choice of endovascular device was made taking into consideration the size of the proximal neck (26 mm) and the ability to adjust length with two grafts. In the future, however, a unitary system of appropriate length and diameter can significantly improve the ease of deployment, limiting access to a single port and thus avoiding the axillary dissection. Endovascular repair of aortic aneurysms with the use of an endoluminal graft was pioneered by Parodi in Since then, multiple devices have been evaluated by investigators, with initial reports appearing in the literature. 11,12 These reports have shown this promising new technology to be safe and effective in the short term for treatment of AAAs. Also, the repair of descending thoracic aortic aneurysms with endoluminal stentgrafts has been attempted successfully in a small group of highly selected patients. 13 These same investigators have performed combined transperitoneal repair of the abdominal aorta and endovascular repair of the thoracic aorta when isolated aneurysmal disease has involved both beds. 14 A completely endovascular treatment of TAAs has not been developed. This would require an endovascular branching system to allow revascularization of the visceral and important intercostal vessels. This technological capability may be developed in the future and would clearly widen the applicability of endovascular therapies for arterial disease. With the available technology, we are somewhat limited in the application of this approach. In this particular case, we had to use two separate grafts, because the present configuration of the Corvita graft was not long enough to bridge the entire aneurysm. In reality, with the use of retrograde visceral perfusion, one could extend this alternative to aneurysms that start higher in the chest, provided there is a proximal neck for proximal attachment. The effect of this approach on spinal cord ischemia is unknown and will require further investigation. Clearly, reimplantation of intercostal arteries alone has not been definitively proven effective in eliminating spinal cord ischemia. 15 Thus, the etiology of this complication is likely multifactorial, with prolonged lower-trunk ischemia and declamping hypotension certainly contributing, which a CESA may minimize. In summary, we have presented a case in which a combined endovascular and surgical approach was used in the management of a type IV TAA. Further experience with this technique and evolution of device technology may establish this approach as a viable alternative in the management of TAAs. REFERENCES 1. Dereume JPE, Ferreira J. The Corvita system. Endovascular surgery for aortic aneurysms. Philadelphia, WB Saunders; p Svensson L, Crawford E, Hess K, et al. Experience with 1509 patients undergoing thoracoabdominal aortic operations. J Vasc Surg 1993;17: Kashyap V, Cambria R, Davison J, L Italien G. Renal failure after thoracoabdominal aortic surgery. J Vasc Surg 1997; 26:

6 560 Quiñones-Baldrich et al September Gilling-Smith GL, Worswick L, Knight PF, Wolfe JH, Mansfield AO. Surgical repair of thoracoabdominal aortic aneurysm: 10 years experience. Br J Surg 1982(5): Jacobs MJ, Eijsman L, Meylaerts SA, Balm R, Legemate DA, et al. Reduced renal failure following thoracoabdominal aneurysm repair by selective perfusion. Eur J Cardiothorac Surg 1998;14(2): Moawad J, McKinsey JF, Wyble CW, Bassiouny HS, Schwartz LB, Gewertz BL. Current results of surgical therapy for chronic mesenteric ischemia. Arch Surg 1997;132(6): Johnston KW, Lindsay TF, Walker PM, Kalman PG. Mesenteric arterial bypass grafts: Early and late results and suggested surgical approach for chronic and acute mesenteric ischemia. Surgery 1995;118(1): McMillan W, McCarthy W, Bresticker M, et al. Mesenteric artery bypass: Objective patency determination. J Vasc Surg 1995;21: Shanley C, Ozaki C, Zelenock G. Bypass grafting for chronic mesenteric ischemia. Surg Clin North Am 1997;77: Parodi J, Palmaz J, Barone H. Transfemoral intraluminal graft implantation for abdominal aortic aneurysms. Ann Vasc Surg 1991;5: Moore W, Rutherford R, Investigators E. Transfemoral endovascular repair of abdominal aortic aneurysm: Results of the North American EVT phase I trial. J Vasc Surg 1996;23: Yusuf S, Baker D, Chuter T, et al. Transfemoral endoluminal repair of abdominal aortic aneurysm with bifurcated graft. Lancet 1994;344: Dake M, Miller D, Semba C, et al. Transluminal placement of endovascular stent-grafts for the treatment of descending thoracic aortic aneurysms. N Engl J Med 1994;1331: Moon M, Mitchell R, Dake M, et al. Simultaneous abdominal aortic replacement and thoracic stent-graft placement for multilevel aortic disease. J Vasc Surg 1997;25: Safi H, Miller C, Carr C, et al. Importance of intercostal artery reattachment during thoracoabdominal aortic aneurysm repair. J Vasc Surg 1998;27: Submitted Feb 4, 1999; accepted Apr 14, 1999.