Newer developments of extra-anatomic bypass.

We have analyzed our eight year experience with more than 200 instances of extra-anatomic bypass and have made certain observations. Extra-anatomic bypass provides an acceptable alternative to extensive direct intra-abdominal and intrathoracic vascular reconstructive procedures. This is particularly true in high risk patients and in the presence of infection. While axillobifemoral bypass is widely known and used, other types of extra-anatomic bypass are emphasized. These are axillary-axillary, axillopopliteal, axillotibial and axillofemoral bypass under local anesthesia. Technical factors, such as the type of graft, the course of the bypass and ancillary techniques to improve the long term patency, are also discussed herein.

Fatal rupture after successful surgical thrombosis of an abdominal aortic aneurysm.

Fatal aortic rupture in a patient 2 weeks after successful thrombosis of an abdominal aneurysm by bilateral iliac artery ligation is reported. The procedure apparently failed to protect the proximal aortoaneurysmal junction, which led to rupture and exsanguination. In view of our present experience, reevaluation of these aneurysm-thrombosing procedures, particularly pertaining to the protection of the proximal aortoaneurysmal junction, is suggested.

Immunocompetence in patients with prosthetic graft infection.

The immunologic competence of 12 patients with advanced and fulminating prosthetic graft infections was studied. Critical deficiencies were noted in the immune status of all the patients. Enhancement of immune responses with accelerated recovery occurred in 8 of the 12 patients who received total parenteral nutritional support. The four patients who exhibited anergy and were not given the benefits of supplemental nutrition endured a prolonged convalescence, and two subsequently died. This study brought to our attention not only the prevalence of depressed host resistance in these critically ill individuals with advanced prosthetic graft injections but also the benefits of adjunctive parenteral nutritional support in combination with the more conventional modes of therapy, including antibiotics, surgical removal of the septic nidus, and bypass to restore arterial continuity.

Prevention of intestinal infarction resulting from mesenteric arterial occlusive disease.

We studied 25 patients with acute intestinal ischemia resulting from arteriosclerotic mesenteric occlusion requiring surgical exploration. Their symptoms were inconspicuous but diagnostically significant. Progressive loss of body weight and symptoms mimicking peptic ulcer disease or cholecystitis were consistent findings. Delay and oversight in the clinical diagnosis resulted in an 80 per cent mortality. We stressed that awareness of possible mesenteric arteriosclerosis in patients with ill-defined gastrointestinal symptoms and weight loss is critical to diagnosis, and early aortography done in the lateral position will define superior mesenteric arterial lesions. Early surgical corrective measures can then be instituted to remedy this critical and often fatal condition.

Total exclusion technique for the management of abdominal aortic aneurysms.

A total exclusion and extraanatomic bypass method has been described for the treatment of abdominal aortic aneurysm. The technique is a one-stage procedure and consists of a right axillofemoral and femorofemoral bypass combined with ligation or plication of the inflow and outflow tracts of the abdominal aneurysm. Successful aneurysmal obliteration is demonstrable intraoperatively by simple palpation for the absence of pulsations. Our experience has affirmed this approach to be remarkably effective in 15 elderly, multiple-risk patients. There were no operative deaths, and morbidity had been low in this small series. The total exclusion technique presented compares favorably with all previously reported nonresective methods based on distal common iliac artery interruption, alone or in combination with injection of thrombotic agents. In particular, the problem of delayed aneurysmal rupture can be avoided with this technique. In view of the recently reported successful use of improved grafts in the axillofemoral position, we believe that the method just described can reliably be applied to high-risk, critically ill patients with abdominal aortic aneurysms.

Extended axillopopliteal-axillotibial bypass. Valuable adjunct to limb revascularization.

Although axillofemoral bypass is now widely used, little has been reported of its more distal extension. Our experience in 12 patients with axillopopliteal (nine) and axillopopliteal-tibial (APT) (three) bypass form the basis of this report. Indications for these extended bypasses included suppurative groin infections and obliterated common and profunda femoris arteries. These procedures were rapidly performed in poor-risk and often critically ill patients. One patient died of recurrent aortoduodenal hemorrhage three weeks following successful APT bypass. The other 11 patients enjoyed patent grafts for periods ranging from six months to two years, although four of these patients successfully underwent a declotting procedure during this period. The early results of these extended APT grafts have been gratifying. This technique would seem to be especially promising for the management of limb ischemia or for rerouting in patients with infected aortic prosthesis.

In situ saphenous vein bypass.

Our 20-year results with in situ saphenous vein grafting in the lower extremity were reviewed and compared wih those where reversed saphenous veins were employed. The ten-year patency rates for both types of grafts terminating at the popliteal artery ranged from 41% to 43% and showed no statistical difference. The reversed saphenous vein performed well in the femoropopliteal position because the vein is usually of the same size at the knee as in the groin and thus does not taper when reversed. We have identified from our study specific indications for the in situ operation. These indications are the presence of small or substantially tapering or bifurcating great saphenous veins that otherwise would be unsatisfactory for conventional reversed vein grafting. We believe that the in situ saphenous vein operation should be considered before resorting to prosthetic leg grafts that carry a lower long-term patency, particularly when carried below the knee.

The left paramedian extraperitoneal approach for aortic reconstructive surgery.

Seventy-five consecutive aortic reconstructive procedures were performed via a left paramedian extraperitoneal approach. These operations included abdominal aortic aneurysmectomies in 28 patients and aortobifemoral grafts in 43. These were combined with aorto-left-renal bypass in four patients and removal of infected aortic prostheses in four other patients. This modified technic obviated the need for excessive retraction by combining the benefits of a paramedian approach with a full-length abdominal incision. Distinct advantage include decrease postoperative abdominal discomfort, minimal paralytic ileus, as well as a shortened convalescence. This extraperitoneal approach is not only suitable for routine aortic reconstructive procedures, but has proven to be especially valuable in cases where increased morbidity is likely with infringement of the peritoneal cavity, such as patients with extensive bowel adhesion, previous colostomy, or infection aortic grafts requiring removal.

Management of chronic visceral ischemia.

The triad of postprandial pain, weight loss, and diarrhea are the hallmarks of abdominal angina. An anastomotic meandering mesenteric artery noted on frontal arteriogram is valuable in signaling significant disease, but lateral views are the sine qua non for diagnosis. Early surgical correction either by local endarterectomy or bypass of a stenotic or occluded segment and accurate selection of cases results in long-term correction of the intestinal ischemia. When advanced occlusive disease of the mesenteric arteries is noted on the preoperative arteriogram of patients selected for aortoiliofemoral, renal artery, or aortic aneurysm reconstructive surgery, concomitant reconstitution of the mesenteric vascular circulation is advisable. It is our opinion that such an approach can be a significant deterrent to subsequent catastrophic bowel infarction from mesenteric arterial occlusive disease.

Aortoenteric fistula.

Because of the unacceptably high mortality rate associated with aortoenteric fistula, we have constantly re-evaluated our experience with this lesion. A study of 31 cases of aortoenteric fistula proven at operation has provided a better understanding of the prevention and management of aortoenteric fistula. Prevention remains the primary goal, as the treatment of this complication even with the adoption of recommendations made in our paper can be expected to continue to carry a significant late mortality rate. The most important point in prevention is to provide adequate protection between gut and graft, using tissue, prosthetic cuff and correct reperitonealization techniques. Systemic or groin infection should be followed by prompt total removal of the graft before the onset of aortoenteric fistula. Once aortoenteric fistula is present, early operation with removal of the graft, proper closure of the aortic and enteric openings, and sump drainage of the area is indicated. Blood supply to the extremities is supplied by extra-anatomic bypass or endarterectomy if the underlying problem is arterial occlusive disease. Paraprosthetic aortoenteric fistulas may be diagnosed early by the presence of fever, blood culture, and a high degree of suspicion. CAT and gallium 67 scanning can be helpful in identifying this early type of fistula.

Extrapleural and extraperitoneal staged technique in successful management of complicated thoracic anastomotic aneurysm.

A simplified, staged technique was employed in the management of a descending thoracic aortic pseudoaneurysm occurring in a thoracic aortobifemoral graft that had been placed 10 years earlier. Our initial procedure comprised ligature of the femoral limbs of the functional thoracic aortobifemoral graft together with a right axilloinfrarenal aortobifemoral bypass. This was followed by definitive descending thoracic pseudoaneurysm management 2 weeks later via a thoracoabdominal extrapleural-extraperitoneal approach. This staged approach provided by a preformed shunt, eliminated the disadvantages of heparinization, hemolysis, or trauma of cannulation during the definitive thoracic aneurysmectomy procedure. Ligature and defunctionization of the original thoracic aortofemoral graft simplified the operative dissection, and the extrapleural and extraperitoneal approach minimized postoperative complications.

Complications after percutaneous transluminal angioplasty.

Percutaneous transluminal angioplasty is being widely advocated as an alternative to direct arterial reconstructive surgery. Distressing complications of percutaneous transluminal angioplasty have been noted, including anterograde dissection of the femoral and iliac arteries with acute thrombosis and widespread embolization of the mesenteric and peripheral circulation leading to death, thrombosis and embolization of the renal arteries with infarction of the kidney and thrombosis of the popliteal trifurcation. While percutaneous transluminal angioplasty promises to be a useful adjunct to our vascular armamentarium in properly selected poor risk patients, we do not believe that it is safer than reconstructive surgery. The most suitable lesions for dilatation appear to be flat, solitary atheromas and segmental scars, which comprise only a small percentage of the total spectrum of the atherosclerosis. An alternative approach to percutaneous transluminal angioplasty entails the combined efforts of the angiographer and surgeon utilizing fluoroscopic guidance and surgical exposure of the affected vessel in the operating room. We hope that employment of the latter technique will result in more selective application of transluminal angioplasty with fewer complications and better long-term results.

Successful management of prosthetic graft infection with continuous povidone-iodine irrigation.

In ten consecutive patients, prosthetic graft infections were managed by a continuous povidone-iodine irrigation technique supplemented by intravenous administration of an appropriate antibiotic. A colostomy bag apparatus was used to ensure constant soaking and immersion of the infected wound. Wound healing occurred in all patients either by secondary intention, direct suturing, or rotation graft technique, and all grafts except one have remained patent and functional over a follow-up period of one to four years. The effectiveness of this management modality permits control of infection without the necessity of prosthetic graft removal and eliminates the need for other intricate bypass operations in these patients with sepsis who are often critically ill.

Concomitant revascularization of intestines during aortoiliac reconstruction: deterrent to catastrophic bowel infarction.

This report points out the necessity for revascularization of the intestines in patients with asymptomatic mesenteric occlusive disease at the time of aortoiliac reconstruction. Emphasis is placed upon the well-being of 15 patients followed up for 2 to 5 years, who underwent concomitant bypass grafting of asymptomatic stenosis or occlusion of the mesenteric arteries, in contrast to the fatal or near fatal outcome of 3 patients who did not receive such corrective measures. Aortomesenteric bypass grafting in conjunction with aortobifemoral bypass grafting or endarterectomy does not involve additional operative exposure or add greatly to the operating time, but may prevent catastrophic bowel infarction resulting from progressive occlusion of the mesenteric arteries.

Stump pressure: an unreliable guide for shunting during carotid endarterectomy.

A correlative analysis was made between the neurological status of the awake patient and the internal carotid artery stump pressure in 125 consecutive patients undergoing carotid endarterectomy. There was no mortality in this series. Twenty-four patients lost consciousness immediately after carotid cross-clamping, even though stump pressures were above 50 mm Hg in more than one third of the cases. The majority (80.8%) of the patients tolerated cross-clamping (stump pressures were between 20 and 90 mm Hg). This study demonstrated the variability of cerebral tolerance relative to absolute stump pressure guidelines, such as 25 or 50 mm Hg; reliance on these values to determine the need for intraoperative shunting could lead to stroke at operation. Our experience also showed that assessment of the awake but tranquil patient continues to be the safest and most reliable guide to selective shunting during carotid endarterectomy.

Renal failure complicating aortoiliofemoral reconstructive procedure.

Fifteen of 20 patients who developed acute renal failure following aortoiliac reconstructive procedures did not survive. Predisposing factors uncovered in this retrospective review include advanced age, associated atherosclerosis in other organ systems, and abnormalities of preoperative renal status. Operative time was shorter and blood transfusion was less in the survivor group. Alerted to the contributing factors and lethan effects of this complication, selection of surgical procedures in these patients might be modified. An extra-anatomic bypass or even amputation may be a safer alternative to reconstructive procedures in certain patients with a high risk of postoperative renal failure.