Endovascular management of thoracic aortic pathology.

BACKGROUND: Endovascular technology has revolutionised the management of abdominal aortic aneurysmal disease but the less frequent occurrence of pathology in the thoracic aorta has meant that evidence demonstrating the primacy of endovascular treatment strategies in this portion of the vessel is less convincing. Herein we summarise the best available evidence to date. METHODS: A comprehensive search of the surgical and radiological literature using the search term 'endovascular thoracic aorta' was conducted. FINDINGS AND CONCLUSIONS: The vast majority of patients treated by thoracic aortic stent grafting have had their treatment outside the context of a randomised trial. While it would seem that endovascular repair is the treatment of choice for the thoracic aorta, the present evidence is based on single centre case series and is anecdotal at best.

Percutaneous endovascular abdominal aortic aneurysm repair leads to a reduction in wound complications.

INTRODUCTION: While endovascular aortic aneurysm repair (EVAR) has significantly reduced the morbidity associated with open surgery, efforts continue to minimise the surgical insult to the patient. We report our experience of percutaneous EVAR. PATIENTS AND METHODS: Since June 2005, 17/20 EVARs (85%) have been attempted percutaneously by deployment of two Perclose) devices into each femoral artery prior to passage of the device sheath. The sutures are left untied until the sheath is removed at the end of the procedure, when haemostasis is obtained. Patients were entered onto a prospectively maintained database and followed up at regular intervals in a dedicated EVAR clinic. RESULTS: Access and subsequent graft deployment was successful in all the 17 cases. The range of defects closed ranged from 12-24 Fr. Five patients (29%) required open groin exploration at the end of the procedure to achieve haemostasis. There was a significantly lower incidence of wound complications in the percutaneous EVAR group (6 vs. 10% open cutdown cases, P < 0.05, Mann-Whitney U test). CONCLUSION: Percutaneous EVAR is both a feasible and safe method of performing endovascular abdominal aortic aneurysm repair, which is associated with a reduction in wound complication rates.

Arcuate-legged nonpenetrating vascular closure staples (VCS): early experience.

Vascular closure staples (VCS) provide a novel technique for fashioning vascular anastomoses, allowing a single operator to perform suture-less anastomoses. They may be used primarily or in an adjuvant role. When VCS are compared to a running suture, advantages include the avoidance of intimal damage, platelet aggregation and intimal hyperplasia at the anastomotic suture line, and a shorter time taken to complete the anastomosis. We report our early experience using VCS in an array of vascular anastomoses and conclude that VCS are a useful addition to the vascular surgeon's armamentarium. They help to decrease the time taken to construct an anastomosis, and are particularly useful in an adjuvant setting, complementing conventionally placed sutures.

Suprarenal mycotic aneurysm exclusion using a stent with a partial autologous covering.

PURPOSE: To report a combined endovascular and open technique to manage a suprarenal mycotic aortic aneurysm using a stent-graft partially covered with a section of autologous artery. METHODS AND RESULTS: A 50-year-old was hospitalized for staphylococcal septicemia and severe back pain. A previously diagnosed 3-cm abdominal aortic aneurysm was found to have expanded 2 cm in 3 weeks. Aortography documented some periaortic thickening and 2 mycotic aneurysms, one posterior at the level of the superior mesenteric artery and the second at the aortic bifurcation. After intensive antibiotic therapy, an endovascular approach to exclude the suprarenal mycotic aneurysm was undertaken in tandem with surgical excision of the infrarenal aneurysm. The harvested right common iliac artery was used to partially cover a Palmaz stent, which was deployed under direct vision just above the renal artery ostia so that the covered portion of the stent excluded the aneurysm. A right axillofemoral bypass with a femorofemoral bypass completed the revascularization. Postoperatively, the patient developed renal failure, ischemic colitis necessitating a left hemicolectomy, and paraplegia. Although the patient is paralyzed, the aneurysm remains excluded with patent visceral vessels at 12 months following surgery. No organisms were grown from excised aortic tissue, and no signs of recurrent infection have been seen. CONCLUSIONS: Stent-graft repair may be able to lessen the invasiveness and reduce the morbidity associated with treatment of mycotic aortic aneurysms.

Endovascular management of rare sciatic artery aneurysm.

PURPOSE: To present a rare case of complete persistent sciatic artery aneurysm successfully treated by coil embolization and to suggest a new classification for this anomaly that encompasses both clinical and pathological factors. METHODS AND RESULTS: A 77-year-old female presented with sudden onset of sharp, throbbing left thigh and foot pain. A nontender 10.0- x 7.0-cm pulsatile mass was found over the inferolateral aspect of the left buttock on examination in the right lateral decubitus position. Angiography demonstrated a 6.9-cm sciatic artery aneurysm with the distal sciatic artery completely thrombosed. Before planned bypass grafting, the aneurysm and distal segment of the internal iliac artery were successfully embolized with coils through a left percutaneous approach. The patient's symptoms resolved with no deterioration in limb perfusion, and further revascularization was unnecessary. Postembolization imaging showed complete occlusion of the aneurysm, which has continued for 19 months. CONCLUSIONS: The application of endovascular techniques and surgical revascularization procedures provides numerous management options for the treatment of an aneurysmal persistent sciatic artery. This case demonstrates that clinical evaluation between staged procedures may obviate the need for further intervention.

Outcome of the first 100 femoropopliteal angioplasties performed in the operating theatre.

OBJECTIVES: To examine the factors influencing outcome and restenosis in an initial series of 100 infrainguinal angioplasties. DESIGN: Prospective study of angioplasties of the superficial femoral and popliteal arteries performed over a 42-month period. MATERIALS AND METHODS: One hundred consecutive angioplasties in 96 patients performed in the operating theatre between January 1993 and June 1996 were followed prospectively with clinical, ABI, and duplex assessment. Forty-four procedures were for disabling claudication and 56 for critical ischaemia. Stents were deployed in 30 limbs. RESULTS: Angioplasty was successful in 84 of 100 limbs. Cumulative patency of the entire group at 3, 6, 12 and 18 months was 78%, 60%, 53%, and 49% respectively, while excluding initial failures, gave patencies of 95%, 69%, 63%, and 58%, respectively. Claudicants with a 1-year patency of 64% did significantly better than patients with critical ischaemia (44% p < 0.05). Angioplasties performed during the initial 21 months had a 1-year patency of 42%, while those performed in the final 21 months had a 74% patency (p = N.S.). The patency for stented arteries was 66% vs. 49% for angioplasty alone (p = N.S.). The 2-year limb salvage rate was 91% in patents with critical ischaemia. Forty-six per cent of restenoses were asymptomatic. CONCLUSIONS: The results suggest that while angioplasty is useful in treating infrainguinal arterial disease, there is a learning curve, resulting in a high restenosis rate for occlusive and multilevel disease, while concomitant placement of stents may be beneficial.

Popliteal aneurysms: a 10-year experience.

BACKGROUND: Popliteal aneurysms account for 70% of peripheral arterial aneurysms and, if untreated, pose a serious threat to the affected limb. Debate continues about the best form of treatment especially for asymptomatic lesions. METHOD: We reviewed the computer records and charts of patients seen at this department with a diagnosis of popliteal aneurysm over the last 10 years. Patients who had not been seen within the last year were followed-up through their G.P. RESULTS: Twenty-four patients (M 23/F 1) presented with 40 popliteal aneurysms. The mean age was 63.5 +/- 9 years. Symptoms were present in 23 of the affected limbs while 17 were asymptomatic. Thirty were treated surgically and 10 followed with regular ultrasound. The mean diameter of the repaired aneurysms was 3.3 +/- 1 cm. Aneurysms < 2 cm were more likely to be asymptomatic. No limbs were lost in patients undergoing elective repair of popliteal aneurysms. The secondary patency and limb salvage rates at 3 years were 84% and 96% respectively. Conservative management of asymptomatic lesions < 2 cm was not complicated by the development of symptoms. CONCLUSIONS: Elective repair of popliteal aneurysms by exclusion and bypass is a safe, effective and durable technique. Small asymptomatic lesions can be safely managed with close follow-up.

Recurrent varicose veins.

Recurrence of varicose veins after treatment has been reported as being between 7% and 65%. During the five month period from August to December 1993, 400 operations on 265 patients were performed for varicose vein disease. Of these, 53 patients had presented with recurrent vein disease in 72 limbs (18%). All patients underwent Duplex scanning of their deep and superficial systems and sites of venous incompetence were identified. The sapheno-femoral junction (SFJ) was found to be incompetent in 52 limbs, of which 31 had previously undergone flush ligation. Sapheno-popliteal junction (SPJ) was incompetent in 33 limbs, while the long saphenous vein (LSV) was found to be incompetent in 67 cases. There were no major complications in this group. Minor complications occurred in 10 cases (14%), mainly in the form of thigh paraesthesia. The more common causes of recurrent disease have been identified and therefore, it should be possible to reduce its incidence. Duplex scanning is essential for any unit dealing with recurrence.

Challenges in diagnosis.

In an ideal world, all patients presenting with leg ulceration would undergo full investigations in order to confirm or refute the proposed aetiology. However, with economic constraints, it is imperative that available health resources are used to the maximum benefit. In our unit, selective investigation is based on the question of whether the result will alter the management of the patient.

Lower extremity bypass for critical ischemia using synthetic conduit and adjuvant vein cuff.

The use of an interposition cuff of vein placed at the distal anastomosis between synthetic bypass conduit and outflow vessel has been advocated to improve patency of lower extremity bypass grafts. Over a three-year period we have performed 43 such bypass procedures: to the above knee popliteal artery (n = 3); below knee popliteal (n = 13), and infrapopliteal arteries (n = 27). There were 20 females and 23 males having a mean age of 70 years (48-84 years). Fifteen patients were hypertensive, 15 were diabetic, and 25 had a history of tobacco use. All cases required limb salvage for rest pain (n = 25), gangrene (n = 10), or ulceration (n = 8) in the absence of suitable autologous vein. Nineteen operations followed a previous failed bypass. Patients were reviewed at six-month intervals. The operative mortality was 8% and two-year primary and secondary patency were 40% and 55%, respectively. Cumulative patency rates were better for first-time grafting procedures than for patients who had undergone previous attempts at limb salvage (60% versus 22%). Two-year limb salvage was 60%. During the same time period, two-year primary and secondary patency rates were 54% and 67%, respectively for autogenous vein. Although the numbers are small these results support the use of an adjuvant vein cuff when employing synthetic grafts. A prospective study of vein versus synthetic graft plus cuff should be undertaken.

Skin closure and the incidence of groin wound infection: a prospective study.

Groin wound infection is a dreaded complication of vascular surgery and may jeopardize an underlying graft. A variety of skin closures have been used and the object of this study was to prospectively determine the relationship between skin closure and wound infection. One hundred fourteen consecutive patients (70 men and 44 women) undergoing bypass surgery with a groin incision (n = 173) were randomly assigned to skin closure with subcuticular Maxon, interrupted nylon, continuous nylon, or clips following a standard two-layer closure of subcutaneous tissue. Fourteen (12%) patients had diabetes and 50 (44%) had digital ulceration and gangrene. Aortofemoral bypass was performed in 25% of the patients and infrainguinal bypass in the remaining 75%. Perioperative wound cultures were obtained before closure. Wounds were inspected and cultures repeated on postoperative days 3, 5, 7, 10, and 14. Infection was defined as a positive culture. Groin wound infection occurred in 3% of the population and graft infection in 0.6%. The type of suture did not influence the incidence of infection. This study failed to demonstrate a significant difference in the incidence of wound infection with the use of different suture materials. We conclude that suture material should be selected on the basis of surgeon preference and costs.

Pentoxifylline and critical leg ischemia.

The annual incidence of critical leg ischemia has been estimated at 500-1,000 patients per million population/year. In critical ischemia there is a breakdown in the microvascular flow-regulating system and inappropriate activation of the microvascular defense system, with resultant endothelial damage and activation of platelets and leukocytes, which leads to further damage of the capillary network. The mainstay of treatment until recently has consisted of interventional procedures. However, these are not always feasible and are not without significant mortality and morbidity. Therefore, attention has been directed towards pharmacologic management. Pentoxifylline inhibits leukocyte aggregation and activation, and improves red cell deformability and oxygen release to tissue. On the basis of these properties, several pilot studies were undertaken, and most have confirmed the benefits of pentoxifylline in the management of critical ischemia. These positive results led to the initiation of a multicenter, double-blind, placebo-controlled study of intravenous pentoxifylline in the acute management of critical ischemia. Results showed a significant reduction in rest pain with pentoxifylline, and outcome was not influenced by various prognostic factors. Research to date suggests that pentoxifylline could have a definite role in the management of patients with critical ischemia.

Improved limb salvage and mobility following peroneal artery bypass.

During the 10-year period August 1981 to 1991, 92 consecutive patients underwent revascularisation to the peroneal artery (40 to the upper third, 30 to the mid and 22 to the distal third). The male/female ratio was 1.6:1 and the mean age was 72 years. Thirteen patients had independent mobility preoperatively while 58 had limited mobility and the remaining 18 were bed/housebound. Following surgery the patients were prospectively evaluated and mean follow-up was 25 months. The 1 and 3 year patency rates were 67 and 59% respectively and cumulative limb salvage rates were 75 and 71%. Forty-four patients returned to independent mobility while 36 had limited mobility and 11 remained housebound. Reconstruction to the peroneal artery is a valuable adjuvant for limb salvage providing satisfactory cumulative patency and facilitating improved mobility.

The comparison of type of incision for transperitoneal abdominal aortic surgery based on postoperative respiratory complications and morbidity.

Equal access to the abdominal aorta can be attained through midline and transverse abdominal incisions. The surgical literature suggests that transverse incisions cause less postoperative pain and morbidity. Fifty patients (10 females and 40 males, mean age 67 years) undergoing abdominal aortic surgery were randomised to a midline (n = 25) or transverse (n = 25) incision. All patients were evaluated preoperatively and postoperatively for seven days. Changes in pulmonary function (FVC and FEV1), time to open and close the incision, analgesia used (morphine mg/kg/h), clinical or X-ray evidence of chest infection, and the duration of ICU stay were recorded. In the transverse group there was a reduction in the incidence of chest complications (20% vs. 28%, p = ns) and these incisions took longer to open (13.9 +/- 4.6 vs. 9.9 +/- 5.1, p < 0.05), but overall there was no significant difference between any other parameter in the two groups. Our results show no statistically significant difference in morbidity or analgesia consumption following transverse or midline abdominal incisions and we conclude that the type of incision used can be left to the surgeon's preference.

Prospective randomized comparison of in situ and reversed infrapopliteal vein grafts.

A three-centre prospective randomized trial was undertaken to compare the efficacy of in situ and reversed saphenous vein grafts for long bypasses to tibial and peroneal arteries. Of 162 patients entered into the study, 82 received an in situ graft and 80 a reversed vein graft. All operations were for limb salvage and the two groups of patients were well matched for age, sex, incidence of diabetes, smoking habits and coronary artery disease. At a maximum follow-up of 3 years there were 48 primary graft failures: 19 in the in situ group and 29 in the reversed vein group. Of these, three in situ grafts and seven reversed grafts were salvaged by secondary intervention. Secondary cumulative patency rates calculated at 3 years after operation were 68 and 66 per cent respectively for in situ and reversed grafts (P not significant). Cumulative limb salvage rates were 78 per cent for in situ grafts and 87 per cent for reversed grafts (P not significant). Separate analysis of a subgroup with small veins (< or = 3.5 mm minimum diameter) showed cumulative patency rates at 2 years of 74 per cent for in situ grafts and 60 per cent for reversed grafts (P not significant). These results indicate that for veins > 3.5 mm in diameter the in situ and reversed techniques for operation are equally effective. Some doubt remains about the best way of using smaller veins; a large number of such veins need to be studied to resolve this question.

Asymptomatic carotid stenosis: a benign lesion?

Recent reports of the risk of asymptomatic carotid stenosis have been compromised by flawed patient selection or the performance of a large number of carotid endarterectomies during follow-up. We report the natural history of a randomly selected group of asymptomatic patients (n = 188; 114 males and 74 females) with documented carotid artery disease who were prospectively followed without intervention for up to 8 years. Risk factors included ischaemic heart disease in 17%, diabetes in 10%, hypertension in 46% and 88% were smokers. The degree of internal carotid stenosis was classified by duplex scanning and a total of 259 vessels had evidence of atherosclerosis. Study end-points included TIA, CVA and death. At mean follow-up of 4 years 3% of the 96 patients with internal carotid artery stenosis of less than 50% had died and 2% suffered a stroke. Six per cent of patients with a stenosis of 50-79% had died and 4% and 2% had suffered a CVA and TIA, respectively. In the 59 patients with greater than 80% stenosis 7% had suffered a TIA and an additional 7% a CVA, while 2% had died. None of the patients suffering a stroke had an antecedent TIA. Though the incidence of ischaemic events is significantly higher in patients with greater than 80% stenosis the incidence of unheralded stroke remains low. We therefore continue to recommend a conservative approach to the management of asymptomatic carotid stenosis.

Infrainguinal polytetrafluoroethylene grafts: saved limbs or wasted effort? A report on ten years' experience.

Two-hundred and twenty-four infrainguinal polytetrafluoroethylene reconstructions were performed for critical ischemia over a 10 year period: 48 to the above-knee popliteal artery, 113 to the below-knee popliteal artery, and 63 to the tibial vessels. The cumulative patency rates were 84 +/- 6% and 63 +/- 9% for above-knee popliteal, 53 +/- 5% and 35 +/- 7% for below-knee popliteal, 45 +/- 6% and 30 +/- 9% for tibial vessels at one and five years respectively. Limb salvage rates were 81 +/- 6% and 73 +/- 9% (above-knee popliteal), 69 +/- 5% and 57 +/- 9% (below-knee popliteal), 64 +/- 7% and 32 +/- 10% (tibial vessels) at one and five years respectively. Graft occlusion did not result in limb loss in 32 cases. Preoperatively, 54% of the patients had limited mobility while 43% were regarded as severely restricted. At follow-up, 57% of the patients were considered to be independent, 26% had limited mobility, and 17% were still severely restricted. Polytetrafluoroethylene provides good short-term limb salvage and improved mobility in patients with critical ischemia and poor life expectancy. Its use is well worth the effort.

Histologic characteristics of carotid artery plaque.

Carotid plaque characteristics associated with the production of symptoms were identified with quantification of carotid plaque constituents in high-grade stenotic asymptomatic (n = 8) and symptomatic (n = 44) plaques. Asymptomatic plaques contained significantly more fibrous/collagen material (88%) than symptomatic plaques (66%) (p less than 0.05). Hemorrhage constituted 2% and 1% of asymptomatic and symptomatic plaques, respectively. The predominant nonfibrous material was a pink amorphous material mixed with cholesterol, which composed 7% of asymptomatic and 27% of symptomatic plaques (p less than 0.05). No relationship was found between plaque composition and the number of ipsilateral ischemic neurologic events, nor was there evidence of a healing process. B-mode ultrasound scanning had a sensitivity of 94% in identifying plaque with greater than 80% fibrous content. We believe that plaque composition may be a useful discriminating factor in selecting asymptomatic patients for carotid endarterectomy.