Revascularization for claudication: Changing the natural history of a benign disease!

OBJECTIVE: The benign natural history of intermittent claudication was first documented in 1960 and has been reconfirmed in several subsequent studies. Excellent outcomes in patients with intermittent claudication can be achieved with exercise therapy and optimal medical management. Professional society guidelines have clearly stated that revascularization procedures should be performed only in patients with incapacitating claudication who have failed conservative therapy. Despite these guidelines, revascularization procedures, primarily percutaneous interventions, have been increasingly utilized in patients with claudication. Many of these patients are not even offered an attempt at medical therapy, and those who are often do not undergo a full course of treatment. Many studies document significant reintervention rates following revascularization, which are associated with increased rates of acute and chronic limb ischemia that may result in significant rates of amputation. The objectives of this study were to compare outcomes of conservative therapy to those seen in patients undergoing revascularization procedures and to determine the impact of revascularization on the natural history of claudication. METHODS: Google Scholar and PubMed were searched for manuscripts on the conservative management of claudication and for those reporting outcomes following revascularization for claudication. RESULTS: Despite early improvement in claudication symptoms following revascularization, multiple studies have demonstrated that long-term outcomes following revascularization are often no better than those obtained with conservative therapy. High reintervention rates (up to 43% for tibial atherectomies) result in high rates of both acute and chronic limb ischemia as compared with those patients undergoing medical therapy. In addition, amputation rates as high as 11% on long-term follow-up are seen in patients undergoing early revascularization. These patients also have a higher incidence of adverse cardiovascular events such as myocardial infarctions compared with patients treated medically. CONCLUSIONS: Revascularization procedures negatively impact the natural history of claudication often resulting in multiple interventions, an increase in the incidence of acute and chronic limb ischemia, and an increased risk of amputation. Accordingly, informed consent requires that all patients undergoing early revascularization must be appraised of the potential negative impact of revascularization on the natural history of claudication.

Long-term Results With CorMatrix Extracellular Matrix Patches After Carotid Endarterectomy.

BACKGROUND: Previous reports of extracellular matrix (ECM) patch use after carotid endarterectomy (CEA) have noted an approximately 10% rate of pseudoaneurysm (PSA) formation. PSA-related rupture of ECM patches has also been described after femoral artery repair. In these studies, different thicknesses (4-ply versus 6-ply) and no standard length of soaking the patch in saline before implantation were used. Herein, we describe our experience with ECM CorMatrix patches in 291 CEAs with 6-ply patches. METHODS: The records of 275 consecutive patients undergoing 291 CEAs with CorMatrix 6-ply patches beginning in November of 2011 and extending until 2015 were reviewed. Only 6-ply patches and a 1 min hydration time in saline were used in all patients. No shunts were used. RESULTS: There were three deaths within the first 30 d secondary to subsequent cardiac surgical procedures. Nine patients experienced a perioperative stroke (3.1%), only one of which occurred secondary to an occluded internal carotid artery. One patient had a transient ischemic attack with a patent endarterectomy site. In follow-up, 11 patients (4.5%) developed severe recurrent stenoses requiring reintervention. Only one patient (0.34%) developed a PSA at 2 years possibly secondary to chronic infection. The median follow-up was 72 mo. CONCLUSIONS: Our experience with 6-ply CorMatrix ECM patches and a brief period of soaking demonstrated that these patches performed well in patients requiring a CEA. Only one PSA was noted.

TSG-6 is highly expressed in human abdominal aortic aneurysms.

BACKGROUND: The formation of abdominal aortic aneurysms (AAA) is characterized by a dominance of proinflammatory forces that result in smooth muscle cell apoptosis, extracellular matrix degradation, and progressive diameter expansion. Additional defects in the antiinflammatory response may also play a role but have yet to be fully characterized. TSG-6 (TNF-stimulated gene-6) is a potent antiinflammatory protein involved in extracellular matrix stabilization and cell migration active in many pathological conditions. Here, we describe its role in AAA formation. METHODS: Blood and/or aortic tissue samples were collected from organ donors, subjects undergoing elective AAA screening, and open surgical AAA repair. Aortic specimens collected were preserved for IHC or immediately assayed after tissue homogenization. Protein concentrations in tissue and plasma were assayed by ELISA. All immune cell populations were assayed using FACS. In vitro, macrophage polarization from monocytes was performed with young, healthy donor PBMCs. RESULTS: TSG-6 was found to be abnormally elevated in both the plasma and aortic wall of patients with AAA compared with healthy and risk-factor matched non-AAA donors. We observed the highest tissue concentration of TSG-6 in the less-diseased proximal and distal shoulders compared with the central aspect of the aneurysm. IHC localized most TSG-6 to the tunica media with minor expression in the tunica adventitia of the aortic wall. Higher concentrations of both M1 and M2 macrophages where also observed, however M1/M2 ratios were unchanged from healthy controls. We observed no difference in M1/M2 ratios in the peripheral blood of risk-factor matched non-AAA and AAA patients. Interesting, TSG-6 inhibited the polarization of the antiinflammatory M2 phenotype in vitro. CONCLUSIONS: AAA formation results from an imbalance of inflammatory forces causing aortic wall infiltration of mononuclear cells leading to the vessel breakdown. In the AAA condition, we report an elevation of TSG-6 expression in both the aortic wall and the peripheral circulation.

The use of cryopreserved aortoiliac allograft for aortic reconstruction in the United States.

BACKGROUND: Aortic infections, even with treatment, have a high mortality and risk of recurrent infection and limb loss. Cryopreserved aortoiliac allograft (CAA) has been proposed for aortic reconstruction to improve outcomes in this high-risk population. METHODS: A multicenter study using a standardized database was performed at 14 of the 20 highest volume institutions that used CAA for aortic reconstruction in the setting of infection or those at high risk for prosthetic graft infection. RESULTS: Two hundred twenty patients (mean age, 65; male:female, 1.6/1) were treated since 2002 for culture positive aortic graft infection (60%), culture negative aortic graft infection (16%), enteric fistula/erosion (15%), infected pseudoaneurysm adjacent to the aortic graft (4%), and other (4%). Intraop cultures indicated infection in 66%. Distal anastomosis was to the femoral artery and iliac. Mean hospital length of stay was 24 days, and 30-day mortality was 9%. Complications occurred in 24% and included persistent sepsis (n = 17), CAA thrombosis (n = 9), CAA rupture (n = 8), recurrent CAA/aortic infection (n = 8), CAA pseudoaneurysm (n = 6), recurrence of aortoenteric fistula (n = 4), and compartment syndrome (n = 1). Patients with full graft excision had significantly better outcomes. Ten (5%) patients required allograft explant. Mean follow-up was 30 ± 3 months. Freedom from graft-related complications, graft explant, and limb loss was 80%, 88%, and 97%, respectively, at 5 years. Primary graft patency was 97% at 5 years, and patient survival was 75% at 1 year and 51% at 5 years. CONCLUSIONS: This largest study of CAA indicates that CAA allows aortic reconstruction in the setting of infection or those at high risk for infection with lower early and long-term morbidity and mortality than other previously reported treatment options. Repair with CAA is associated with low rates of aneurysm formation, recurrent infection, aortic blowout, and limb loss. We believe that CAA should be considered a first line treatment of aortic infections.

Long-term results with cryopreserved arterial allografts (CPAs) in the treatment of graft or primary arterial infections.

OBJECTIVE: Our purpose was to evaluate our results with CPAs in patients with infected grafts or primary arterial infection with emphasis on long-term durability of these grafts. METHODS: To evaluate the long-term durability of CPAs, clinical outcomes were analyzed following their use for either graft or primary arterial infections at a single institution over a 9-y period (2000-2009). The 30-d mortality rate, 90-d mortality rate, and the cause of early mortality were determined in each case. Among those surviving 90 d, the grafts were evaluated for subsequent failure. RESULTS: From 2000 through 2009, 51 patients with either infected prosthetic grafts (35) or primary arterial infections (15) received CPAs. One patient had infection of a previously placed thoracic allograft. Forty-three graft infections involved either the thoracic or abdominal aorta. Eleven patients presented with fulminant sepsis with systemic inflammatory response syndrome (SIRS), seven of whom died postoperatively. Eight patients presented with aorto-enteric, esophageal, or bronchial fistulae with infected prosthetic grafts. The 30-d mortality rate was 25.5% (11 deaths) seven of which occurred in patients with SIRS. The 90-d mortality rate was 41.4%. There were 10 graft failures, seven occurring in patients with aorto-enteric or bronchial fistulae all of whom had recurrent hemorrhage. The other three graft failures were due to anastomotic hemorrhage in the early postoperative period. Among those surviving 90 d, the mean follow-up was 46.4 mo (range 1-112 mo). No aneurysmal degeneration of the CPAs was noted. Only one subsequent allograft graft failure was noted among those surviving more than 90 d. CONCLUSIONS: CPAs are a suitable option in dealing with cardiovascular infections. Patients with enteric or bronchial fistulae are a difficult group to treat perhaps because of ongoing contamination of the allograft. The operative mortalities are largely determined by patient comorbidities (SIRS). Subsequent degeneration or infection of the CPAs is rare.

Spontaneous iliac vein rupture: An uncommon, but frequently lethal, event.

Spontaneous rupture of the iliac veins is a distinctly uncommon problem often misdiagnosed as an arterial rupture because of significant retroperitoneal bleeding. It often occurs with acute left-sided deep vein thrombosis and physical activities that exacerbate acute venous hypertension. A significant number of these patients will have anatomy associated with May-Thurner syndrome. Delayed imaging on computed tomography scanning might suggest a venous etiology for a retroperitoneal hematoma rather than arterial bleeding. We found 53 previously reported cases of iliac vein rupture Our report details two additional cases and the treatment options and outcomes.

Erosion of elephant trunk Dacron graft limb by thoracic endograft causing acute aneurysm expansion.

We recently treated a patient in whom a Gore TAG thoracic endograft (W.L. Gore and Assoc, Flagstaff, Arix) had been used to repair a descending thoracic aneurysm as the second stage of a hybrid procedure. This patient had previously undergone repair of ascending and aortic arch aneurysms, with an elephant trunk graft limb placed in the descending thoracic aorta for subsequent repair of the descending thoracic aneurysm. Eight months after placement of the thoracic endograft, the patient presented with an acutely expanding and symptomatic thoracic aneurysm. The patient was operated on urgently. The proximal portion of the endograft had eroded into the previously placed Dacron elephant trunk limb. The proximal portion of the endograft was removed and was replaced with a Dacron graft. The management of this patient forms the basis of this report.

Case study: chronic femoropopliteal prosthetic graft infection with exposed graft.

One of the most feared complications following vascular reconstruction is infection due to the attendant risks of limb loss, sepsis, or death. The reported incidence of infection following infrainguinal prosthetic graft infection is 2.5% with associated mortality rates and amputation rates of 18% and 41%, respectively. There are several options in treating infected prosthetic infrainguinal bypass grafts. Some authors have advocated complete removal of the infected graft with concomitant in situ revascularization using autogenous tissue or extra-anatomic bypass using either autogenous or prosthetic material, depending upon the clinical circumstances. Other authors have advocated attempting graft preservation to decrease the risk of amputation. Infected, thrombosed grafts are generally treated with graft excision alone with care taken to preserve collateral flow. The treatment options may also be influenced by the type of infection, as infections caused by gram-negative bacteria are thought to be more virulent than those associated with gram-positive bacteria. We recently treated a patient with an 18-month history of an exposed prosthetic graft in the groin, which was infected by Proteus mirabilis. Despite the extended period of graft exposure and despite gram-negative bacteria being the causative organism, the patient reported only intermittent drainage of pus from the groin. The management of this unusual infection forms the basis of this report.

Combined thenar and hypothenar hammer syndromes: case report and review of the literature.

Patients who use the palms of their hands as a hammer may cause irreversible damage to the radial or ulnar arteries. Damage to the intima may lead to arterial thrombosis, whereas damage to the media may cause aneurysm formation with embolization to the digital arteries, causing symptoms of ischemia. These patients may have symptoms of Raynaud syndrome, or they may have ischemic ulcerations of their fingers. Hypothenar hammer syndrome with involvement of the ulnar artery is much more frequently encountered than thenar hammer syndrome, which is caused by damage to the radial artery. We report a patient with symptomatic occlusion of both the radial and ulnar arteries secondary to repetitive trauma to the palm of his hand. In our review of the literature, we found two reports involving a total of four patients with similar findings. Both conservative and surgical treatments have been used successfully. Avoidance of the precipitating activities is important in long-term management of these patients.

Complete endograft collapse 91/2 years following endograft repair of an abdominal aortic aneurysm.

Endografts are a common method of treating abdominal aortic aneurysms (AAA) because of the short-term benefits of endovascular aneurysm repair (EVAR). However, the short-term benefits of endovascular repair must be balanced against long-term complications, such as the need for conversion to open repair, device migration, persistent or de novo endoleaks, and most concerning the potential for subsequent rupture of the aneurysm. Lifelong postimplantation surveillance is mandatory because the incidence of some complications increases over time. This report describes our recent experience in a patient in whom complete endograft collapse was discovered 9(1/2) years following EVAR necessitating conversion to open repair.

Infected splenic artery aneurysm with associated splenic abscess formation secondary to bacterial endocarditis: case report and review of the literature.

Infected aneurysms are rare and may present with rupture or sepsis. Surgical treatment is often required to prevent catastrophic sequelae. Bacterial endocarditis is one of the classic causes of infected aneurysm. We present a case of a 6.1-cm infected splenic artery aneurysm secondary to endocarditis. Surgical treatment consisted of aortic and mitral valve replacements, splenic artery aneurysm resection, and splenectomy. We reviewed five other reported infected splenic artery aneurysms in which documented ruptured had occurred in three patients. Because the rate of rupture in these patients appears to be quite high, infected splenic artery aneurysms require prompt treatment.

Subclavian venous aneurysm: case report and review of the literature.

A case of a symptomatic 5.1-cm left subclavian venous aneurysm, which was treated with surgical excision, is presented. Most venous aneurysms in the head and neck region involve the internal or external jugular veins and are asymptomatic. Aneurysms involving the subclavian or axillary veins are rare. The natural history of these aneurysms is benign with no reported instances of rupture or thromboembolic events. Operative treatment is most often undertaken for cosmetic reasons or for the development of symptoms.

Arterial infections in the new millenium: an old problem revisited.

The natural history of infected aneurysms or arterial infections is characterized by rapid expansion leading to rupture, pseudoaneurysm formation, and sepsis. Treatment options include in situ grafting either with prosthetic or autogenous grafts or with cryopreserved allografts (CPAs), resection of the aneurysm with remote bypass grafting, and ligation. The purpose of this study was to review our recent experience with these infections and to present long-term follow-up with in situ CPAs. From January 2000 through June 2005, we treated nine patients with infected aneurysms and one patient with an infection without aneurysm formation. The infection involved the infrarenal abdominal aorta in six patients and the femoral artery in three patients. One patient had an infected splenic artery aneurysm. Aortic rupture occurred in five of the six patients with infected aortas. Two of the three patients with infected femoral aneurysms presented with recurrent hemorrhage. Of the six patients with aortic infections, five were treated with in situ CPAs. One patient was treated with aortic resection and axillofemoral grafting. Two patients with femoral aneurysms were treated with in situ CPAs, and the third patient underwent aneurysm resection and prosthetic grafting through the obturator foramen. The patient with the splenic aneurysm underwent combined valve replacement, aneurysm resection, and splenectomy. Three of the six patients with aortic infections died postoperatively, all of whom were septic at presentation. The cause of death in these three patients was multiple organ failure in two and overwhelming sepsis in one. The three survivors are alive and well with up to 5-year follow-up. The three patients with infected femoral aneurysms are alive and well with follow-up extending to 44 months. The patient with the splenic aneurysm is doing well. No recurrent infections have been noted among the survivors. The CPAs have remained structurally intact in all. The mortality rate among patients with abdominal aortic infections remains high and is likely related to their preoperative septic state. In situ grafting with CPAs appears to be a reasonable treatment option for arterial infections. CPAs appear to maintain their structural integrity and to be resistant to recurrent infection.

Pseudoaneurysm formation in a subset of patients with small intestinal submucosa biologic patches after carotid endarterectomy.

BACKGROUND: The carotid artery is frequently patched after carotid endarterectomy (CEA) to minimize the risks of early postoperative thrombosis and late recurrent stenosis. The small intestinal submucosa (SIS) patch is a biologic vascular patch derived from porcine small intestine. It is composed primarily of cell-free collagen and other extracellular matrix constituents that act as a scaffold for host cell deposition. METHODS: In May 2001, we began an investigational trial of SIS patches in 76 patients undergoing patch angioplasty of the carotid artery after CEA. RESULTS: No adverse events related to the patches were observed in the first 69 patients implanted with an SIS patch. However, in late 2002, seven patients were found to have asymptomatic pseudoaneurysms (PSA) by duplex imaging < or =10 weeks after their CEAs. The trial was immediately suspended. The PSAs were treated by surgical resection with vein grafting in two patients and placement of covered endoluminal stents in four patients. One patient is being followed as the PSA is small and has remained stable. Histopathologic examination of the SIS patch explanted from one of the surgically treated patients demonstrated the presence of actin-positive myofibroblasts or smooth muscle cells. Extensive mechanical testing of the SIS material from the two material lots associated with PSAs demonstrated thinner and more variable physical characteristics compared with control device lots. CONCLUSIONS: Biologic patches that undergo active remodeling in the carotid artery require greater thickness than was anticipated to decrease wall stress and suture hole elongation. Patches exceeding this minimum thickness will be required to ensure the safety of new SIS patch designs for vascular operations.

Surgical resection of a large recurrent pelvic arteriovenous malformation using deep hypothermic circulatory arrest.

Transcatheter embolization has emerged as the treatment of choice for pelvic arteriovenous malformations (AVMs), because surgical resection may be difficult and is associated with a high recurrence rate. We report a patient with a large recurrent pelvic AVM in whom transcatheter embolization was not feasible. This patient underwent surgical resection of the AVM, which was accomplished with deep hypothermic circulatory arrest. Early postoperative angiography demonstrated a small amount of residual AVM, which was successfully embolized with microcoils. Follow-up magnetic resonance angiography at 2 months showed no residual AVM. In cases where surgical resection of an extensive AVM is required, deep hypothermic circulatory arrest offers the distinct advantages of performing the resection in a bloodless field and enabling adequate visualization of important adjacent structures.