Treatment of abdominal aortic aneurysm by exclusion and bypass: an analysis of outcome

Abdominal aortic aneurysm is conventionally treated by aneurysmorrhaphy with inlying graft. Alternatively, division of the aorta, with suture closure of the distal aorta and outflow vessels (exclusion of the aneurysm), and end-to-end proximal to distal bypass may be performed. However, the long-term fate of this operation has not been determined. Specifically, concern exists that the excluded blood filled aneurysm may not thrombose or may be the source of late sepsis. During an 8-year period we have treated 280 abdominal aortic aneurysms (urgent and elective) by exclusion of the abdominal aortic aneurysm sac and bypass via the posterolateral retroperitoneal approach. Mean age was 70 years (range, 44 to 88), with 217 men and 63 women. Preoperative CT scanning and aortography were performed to assess arterial anatomy. Seventy tube grafts and 260 bifurcation grafts were used. Thirty-day mortality rate was 4%. Estimated blood loss was 731 +/- 52 ml; mean transfusion requirements were 456 +/- 82 ml. The minor complication rate was 6%, and it is of great interest that there were no cases of ischemic colitis requiring colectomy. Aneurysm sacs thrombosed except in two anticoagulated patients who required further treatment. No late infections occurred. Five-year bypass patency rate was 98%. These data demonstrate that this method of treatment effectively minimized operative dissection and blood loss and therefore is a viable alternative for the management of abdominal aortic aneurysms.

Antibiotic therapy for arterial infection: lessons from the successful treatment of a mycotic femoral artery aneurysm without surgical reconstruction

A mycotic femoral artery aneurysm developed in a diabetic man with bacteremia from a Staphylococcus aureus urinary tract infection. Because of severe concomitant congestive heart failure and hypothyroidism, surgical reconstruction of the femoral artery was deferred while the patient received an intensive course of intravenous nafcillin. This led to stabilization of the size of the femoral aneurysm for two years, during which time it remained asymptomatic. Three such cases of nonsurgical treatment of a mycotic aneurysm have been documented. Surgical ligation, drainage, and bypass remain the mainstay therapies for mycotic aneurysms, but these cases demonstrate the possibility of sterilizing a primary arterial infection under the highly selected circumstances of an exquisitely sensitive organism, absence of periarterial abscess and readily observable anatomic location. Most importantly, these cases provide assurance that a six-week course of parenteral antibiotics is a reasonable adjunctive treatment for residual endovascular infection.

Hemodynamic characteristics of failing infrainguinal in situ vein bypass

The successful follow-up of distal arterial reconstructions for the identification of the failing bypass in the postoperative period hinges on a knowledge of the natural history of flow characteristics in these reconstructions. Over a 4-year period resting and hyperemic bypass flow, fistula flow, conduit diameter, and distal peak systolic velocity of 350 in situ bypasses were measured serially. B-mode ultrasound imaging of the entire bypass was performed to identify specific stenoses. Measurements were performed 5 to 9 days after operation, every 2 months for the first year, and every 6 months thereafter. Distal bypass flow less than 25 ml/min, a ratio of hyperemic/resting distal bypass flow less than 2.5, and vein size less than or equal to 3.0 mm inner diameter all correlated with bypass stenosis (greater than 50%) or occlusion (p less than 0.01). Contrary to previous studies, a distal peak systolic velocity of less than 45 cm/sec did not correlate with bypass stenosis or occlusion. A low distal peak systolic velocity did correlate with bypass stenosis or occlusion in bypasses larger than or equal to 3.5 mm inner diameter (p less than 0.03). However, no combination of these factors was able to accurately predict preocclusive stenosis or occlusion. Distal bypass flow was highest initially but reached a plateau 6 to 12 months after operation. Fistula flow, although very high initially, showed marked decrement with time.

Immediate preoperative phlebotomy with autologous blood donation for aortic replacement

The preferential use of autologous blood provided by phlebotomy can reduce the need for homologous blood transfusion in patients undergoing extensive elective operations. This blood is usually provided either by intraoperative isovolemic hemodilution or phlebotomy one to two weeks preoperatively. To minimize the intraoperative time delay or preoperative period between phlebotomy and operation required in these patients, we performed preoperative isovolemic hemodilution in 69 patients one to two days prior to elective aortic replacement for infrarenal aneurysmal disease. Patients underwent phlebotomy a mean of 0.57 +/- 0.01 liter of whole blood; volume was replaced with lactated Ringer's solution. Hematocrit levels decreased from a mean value of 42.9 +/- 0.4 per cent to 33.7 +/- 0.3 per cent. Mean intraoperative blood loss was 1.2 +/- 0.05 liters. Hemodynamic parameters (blood pressure, cardiac output, pulmonary capillary wedge pressure, central venous pressure, oxygen delivery and systemic vascular resistance) remained stable throughout the perioperative and intraoperative time periods. In addition, we evaluated the technical modification of exclusion aneurysmorrhaphy (n = 50) versus open aneurysmorraphy (n = 19) on reduction of intraoperative homologous blood transfusion in these patients. Seventy-two per cent (36 of 50) of patients whose aneurysms were excluded received no homologous blood intraoperatively. Blood loss was decreased in the excluded versus open aneurysmorraphy group, 920 +/- 90 milliliters versus 2,030 +/- 250 milliliters, as were homologous blood transfusion requirements, 175 +/- 35 milliliters versus 570 +/- 119 milliliters. Two patients died (2.9 per cent mortality rate), and there was no increase in morbidity. Surgical treatment of large aortic aneurysms is frequently performed on an urgent basis; thus, provision of autologous blood for this operation in a short period of time may be beneficial. Isovolemic hemodilution performed during the immediate preoperative period can reduce homologous blood requirements and be safely performed without adverse effects on mortality, morbidity and myocardial performance. Exclusion aneurysmorrhaphy may further reduce dependence on homologous blood.

Results of infrainguinal bypass for limb salvage in patients with end-stage renal disease

Limb salvage in patients with end-stage renal disease (ESRD) is complicated by the diffuse, obstructive, calcific arteriopathy that makes anastomotic technique especially critical. Furthermore, decreased resistance to infection and impaired wound healing produced by host-factor deficiencies such as diabetes mellitus, hypoalbuminemia, uremia, and immunosuppression produce additional obstacles to successful limb salvage. This report summarizes our experience with distal arterial bypass procedures in these patients. A total of 32 bypass procedures were performed for limb salvage in 24 patients (17 diabetic) during a period of 5 years. The operative mortality rate was 6%. During the same period, 635 infrainguinal bypass procedures were performed by the in situ technique in patients without ESRD. Primary bypass patency was comparable in both groups at 24 months (92% vs 90%). In the group with ESRD, overall limb salvage was 83% at 2 years. Life-table analysis of bypass patency and limb salvage was thought not to be appropriate in the population with ESRD beyond 2 years because of the increased mortality rate (38%; 9/24) during this interval. It is important that limb salvage was achieved in diabetic patients with ESRD in the presence of extensive foot gangrene or ischemic ulceration. Revascularization should be considered strongly for limb salvage in all patients in this difficult population.

Left retroperitoneal exposure for distal mesenteric artery repair

Distal disease in the mesenteric arteries has usually been repaired transabdominally since it is believed that only the proximal centimeter of each vessel is accessible through the retroperitoneum. We treated five patients with chronic visceral ischemia and lesions extending beyond the orifice using a retroperitoneal approach. Exposure was obtained with a left flank incision through the tenth interspace. The left crus of the diaphragm was divided in order to control the supraceliac aorta. The mesenteric vessels were identified and dissected until their entrance into the peritoneum. There were no difficulties in exposing the superior mesenteric artery (SMA) as it coursed under the pancreas and over the duodenum for an approximate length of 5 to 10 cm. The uncinate process of the pancreas was not a limiting factor for exposure of the SMA in this region and further distal exposure could be obtained by incising the peritoneum. The trifurcation of the celiac artery and the splenic artery were accessible through this exposure; however, only the first centimeter of the hepatic and gastric branches could be reached. Revascularization was performed with endarterectomy (2 patients) and bypass (3 patients). Bowel viability was assessed at the conclusion of the procedure by incising the peritoneum. There were no complications from this exposure and no patient required reoperation for ischemic bowel. We conclude that the left retroperitoneal approach is not only acceptable for orifice lesions but is also applicable for distal disease.

Impact of the presence of orthopedic hardware on technical performance of major amputations

Metallic prostheses used for joint reconstruction or open reduction of fractures were discovered pre- or intraoperatively during the performance of six above-knee amputations. The prosthesis was found fortuitously before surgery in two cases on the basis of a surgical scar or radiograph of the leg. In four patients, discovery occurred intraoperatively, with adverse impact on the procedure in two cases: more proximal amputation level to allow hip nail removal was necessary in one case, and difficult transection of the prosthesis stem was encountered in one case. Orthopedic prostheses will be found with an increasing incidence in the population undergoing major amputation. As preparation for amputation, a careful review of the patient's history, a search for scars over the leg and hip, and survey radiographs of the leg must be obtained to prevent a surgical mishap caused by accidental discovery of a prosthesis.

The role of extraanatomic exclusion bypass in the treatment of disseminated atheroembolism syndrome

We treated six patients with disseminated atheroembolism complicated by severe and unremitting pain from bilateral foot lesions. All patients had multiple and severe medical risk factors. One patient had a recent myocardial infarction, six patients had renal failure, and three were undergoing hemodialysis. Definitive aortic reconstruction was therefore precluded. After failing a course of medical therapy, each patient was treated with axillobifemoral bypass with exclusion-ligation of the external iliac arteries. Healing of foot wounds occurred in 11 of 12 limbs at risk, with one below-knee amputation required for progressive forefoot necrosis. In 12 patients with severe cardiopulmonary disease and limited life expectancy, exclusion-ligation bypass is an effective and safe palliative procedure for severe disseminated atheroembolism.

Can the retroperitoneal approach be used for ruptured abdominal aortic aneurysms?

The retroperitoneal approach for elective treatment of abdominal aortic aneurysms is an accepted alternative to midline transperitoneal approaches and may provide less physiologic insult and a smoother postoperative course. In recent years we have preferentially used the extended retroperitoneal approach for ruptured abdominal aortic aneurysms to derive similar physiologic benefits for these patients. Over a 6-year period (1983 to 1989) 76 cases of ruptured abdominal aortic aneurysms were treated by emergency aortic replacement. After exclusion of 13 patients whose aneurysmal ruptures were unusual, such as aortoenteric fistula, aortocaval fistula, chronic contained rupture, or visceral involvement, 63 patients were retrospectively studied. Thirty-eight patients were treated via a standard transperitoneal celiotomy and 25 via a left retroperitoneal incision. No significant differences were found between the two groups in regard to cardiac or pulmonary function or duration of preoperative hypotension. Operative mortality was lower in the retroperitoneal group (three of 25, 12%) as compared to the transperitoneal group (13 of 38, 34.2%). Furthermore, the retroperitoneal group required less ventilatory support and tolerated enteral feedings quickly. Length of stay in the hospital was also significantly reduced in the retroperitoneal group. These data indicate that many ruptured abdominal aortic aneurysms can be successfully treated through the left retroperitoneal approach. In this nonrandomized clinical series increased survival rates and shorter periods of postoperative recovery were noted in the patients operated with the retroperitoneal approach.

Remote distal arteriovenous fistula to improve infrapopliteal bypass patency

The results of the use of prosthetic materials for femorocrural bypass surgery have been less than optimal. The creation of a distal anastomotic arteriovenous fistula to augment blood flow and velocity through the graft is well known. However, it may create turbulence at the anastomosis and steal blood flow away from the distal artery. A canine model was developed to evaluate the effect of fistula size on graft/arterial hemodynamics. In 16 patients we have constructed a distal arteriovenous fistula, which is remote from the distal anastomosis, and we studied the effect of such fistulas on bypass patency and distal arterial hemodynamics. Patients selected for this procedure had multiple previously failed reconstructions and limb-threatening ischemia and did not have usable autogenous vein. Femorotibial bypass graft reconstructions were performed with polytetrafluoroethylene followed by the creation of a side-to-side arteriovenous fistula 5 to 15 cm below the distal anastomosis in the same artery and accompanying veins. We have achieved a 1-year patency of 67% with a 75% limb salvage rate. We also serially measured blood flow and velocity within the bypass, the arteriovenous fistula, and the distal outflow vessel using duplex scanning after surgery. Mean estimated blood flow through the bypass during the immediate postoperative period was 264 ml/min, the arteriovenous fistula was 157 ml/min, and the distal artery was 19 ml/min. Unlike an arteriovenous fistula created at the distal anastomosis, a remote distal arteriovenous fistula not only increases graft blood flow but also augments native arterial blood flow between the distal anastomosis and fistula and thus may improve distal limb perfusion.

Changes in steady-state levels of mRNAs coding for type IV collagen, laminin and fibronectin following capillary basement membrane thickening in human adult onset diabetes

The development of capillary basement membrane thickening has been linked to microvascular changes known to occur in tissues of patients with type II diabetes. Previous evidence has suggested that capillary basement membrane thickening is due to increased basement membrane synthesis. In this study, skin samples from 8 diabetic patients with confirmed capillary basement membrane thickening and 7 non-diabetic controls were used to assess steady state levels of mRNAs coding for several basement components including pro alpha 1(IV) collagen, laminin and fibronectin. Total RNA was extracted from abdominal skin samples and levels of mRNAs coding for the basement membrane components laminin, fibronectin and pro alpha 1(IV) collagen, a fibrillar collagenous protein, pro alpha 1(I) collagen and an intracellular polypeptide, gamma-actin, were determined by dot blot hybridization analysis. While there were no changes of steady state levels of pro alpha 1(I) collagen mRNA and laminin mRNA, a significant reduction was noted in the quantitative recovery of mRNA levels for pro alpha 1(IV) collagen, gamma-actin and fibronectin in total RNA isolated from the skin of diabetic patients. This reduction in levels of mRNAs coding for basement membrane components contrasts with pathological confirmation of an accumulation of endothelial capillary basement membrane in skin from diabetic patients and suggests that basement membrane thickening arises more as a consequence of reduced basement membrane degradation than elevated synthesis of basement membrane components.

In situ bypass hemodynamics. The effect of residual A-V fistulae

The effect of arteriovenous fistulae on in situ saphenous vein bypass hemodynamics and patency rates has been of great concern to some. It is our practice to ligate only those fistulae which conduct enough dye upon completion angiography to visualize the deep femoral venous system. We have prospectively studied 216 such bypasses using duplex ultrasound scanning to assess overall hemodynamic function over periods from 1 to 156 months postoperatively. Volumetric blood flow was measured in proximal and distal portions of the bypass choosing a region of uniform diameter with laminar flow. Mean fistula flow was derived by subtracting distal bypass flow from proximal bypass flow. Distal flow decreased significantly (p less than 0.01 paired t-test) from 68 +/- 4.6 ml/min (mean +/- SEM) at 2 months postoperatively to 51 +/- 4.8 ml/min at 12 months postoperatively. There was an overall decrease in fistula flow from 256 +/- 26.9 ml/min at 2 months to 86 +/- 22.6 ml/min at 12 months. In 14 of the 216 bypasses (6.5%), arteriovenous fistulae were ligated during the first postoperative year. This was necessitated by persistent increased fistula flow with or without edema and indication from PVR or segmental pressure of decreased resting flow or pressure. Following fistula ligation, fistula flow decreased and distal bypass flow improved. Within this select group of patients with reduced flow capacity, i.e., a proximal stenosis or small vein size, high fistula flow is poorly tolerated with a significant redistribution of flow resulting in reduced distal perfusion. However, for the majority of patients (95%), fistula flow does not deleteriously affect distal bypass flow.

The right retroperitoneal approach for abdominal aortic surgery

Retroperitoneal exposure of the abdominal aorta is usually performed through a left flank incision. An alternative approach to the abdominal aorta is described utilizing a right flank incision. Indications for the use of the right retroperitoneal approach during surgery for aortic aneurysms include right renal artery stenosis, right iliac artery aneurysm, need for simultaneous cholecystectomy, multiple or recent intraabdominal procedures, and sigmoid colostomy. A series of 17 patients is presented to illustrate the utility of this approach. There was one operative death in an emergent patient; the cause of death was not related to the method of aortic exposure. The remaining patients recovered quickly. The anatomic advantages and limitations of this exposure are discussed. We believe that retroperitoneal aortic exposure is superior to midline transperitoneal exposure. Aortic exposure utilizing a right retroperitoneal approach is a useful option in the surgical armamentarium.

Comparative analysis of retroperitoneal and transperitoneal aortic replacement for aneurysm

Transabdominal aortic replacement is the most widely accepted surgical approach in the treatment of infrarenal abdominal aortic aneurysms (AAA) with an enviable mortality rate of 2 to 5 per cent. This approach, however, is attended by significant intraoperative loss of fluid and subsequent translocation as well as impaired postoperative pulmonary function and ileus. Although the retroperitoneal exposure of the aorta was used for the first repair of an AAA by Dubost and has been championed more recently by others, it has not been widely accepted. Experience suggests, however, that the exposure is as good and that postoperative morbidity is significantly less than that with the transperitoneal approach. In the past five years, we have surgically treated 299 AAA, 106 by the transabdominal route and 193 by the extended retroperitoneal approach. In 133 of the 193 patients upon whom the retroperitoneal approach was used, the aneurysm was left intact after division of the infrarenal aorta for an end to end proximal anastomosis of an aortoaortic to iliac to femoral bypass. There has been a significant reduction in the intraoperative replacement of fluid and blood, in postoperative respiratory support, in length of time in the intensive care unit and in occurrence of postoperative ileus when compared with the transabdominal endoaneurysmorrhaphy approach. Furthermore, the exposure, particularly upon the obese patient, is superior. Findings from this experience using the retroperitoneal approach for repair of AAA indicate that it results in less over-all physiologic disturbance of the patient.

Sartorius muscle coverage for the treatment of complicated vascular surgical wounds

Sartorius muscle flaps were evaluated in 14 patients treated for complicated groin wounds related to vascular surgical procedures. Particular risk factors for poor wound healing were present in 8 patients, including diabetes, obesity, or poor nutrition in 3 patients; prior radiotherapy to the groin in 2; reoperative groin exposure in 3. Eleven of 14 patients had multiple indications for sartorius flap coverage, including hemorrhage in 5 patients, groin wound sepsis in 3, graft sepsis in 2, wound necrosis in 5, exposure of a reconstruction in 4, treatment of a lymphocele in 1, and treatment of groin irradiation in 2. Nine flaps were proximal sartorius segments rotated into the groin, four were distal muscle reflected into the groin, and one was a mobilized mid-portion of the muscle. Early successful wound healing occurred in all patients, but complications included muscle bed infection in 1 patient, late recurrence of lymphocele in 1, and recurrent groin sepsis in 1. Hemorrhage did not recur, and existing reconstructions were salvaged in all patients. The sartorius flap is a well-tolerated method for achieving autogenous tissue coverage for the problem groin wound, and there is no long-term functional deficit from anatomic loss of the sartorius muscle.

Comparison between selective distal splenorenal shunt and small diameter H-graft portosystemic shunt

Although most commonly performed portal decompressive procedures control bleeding effectively, postoperative morbidity and mortality remains a serious problem in these patients. Both distal splenorenal shunts (DSRS) and small-diameter portacaval H-grafts (PCHG) are reported to produce decreased rates of postoperative encephalopathy. We prospectively evaluated 69 patients in whom 27 PCHG and 45 DSRS were performed over a seven-year interval. There were no significant preoperative differences between these groups. Operative mortality was 12.9% overall. DSRS was associated with decreased intraoperative blood transfusions and operative time. Postoperatively, DSRS was associated with significantly less encephalopathy, other postoperative complications, and ascites. Recurrent variceal bleeding was seen in three patients treated with PCHG and two patients with DSRS. We conclude that both DSRS and PCHG are effective in preventing recurrent variceal bleeding, but DSRS remains our procedure of choice because of its decreased rates of postoperative complications.

The fate of extremities with flat lower calf pulse volume recordings

The prognosis of patients with a flat (Class 5) or nearly flat (Class 4) pulse volume recording was studied in relation to the signs and symptoms of vascular disease in 517 patients. Within one year of follow up, 97.9% of 96 patients with jeopardized limbs and flat tracings required surgery, whereas 72.4% of 29 patients with no or minimal symptoms required reconstruction (p less than 0.001); 85.7% of patients with Class 4 tracings and jeopardized limbs required surgery, whereas 41.9% of those with minimal symptoms and Class 4 recordings developed need for reconstruction (p less than 0.001). The requirement for surgery Class 5 patients is significantly higher than in those with Class 4 tracings. The general trend of pulse volume recording amplitude to correlate with ankle systolic blood pressure was confirmed. One year mortality in Class 5 patients was 43.2%. The majority of patients with severely abnormal pulse volume recordings eventually come to surgical reconstruction. The timing of surgery is based on the clinical status of the jeopardized limb, not solely on the presence of a pulse volume tracing abnormality.

Flow/velocity characteristics of arterial bypass stenoses

In the carotid system with relatively constant blood flow, peak systolic velocity within a stenosis (PSVST) can characterize the degree of hemodynamic stenosis. We have studied flow/velocity characteristics in an in vitro model of stenosis within conduits of varying diameters in an attempt to quantify the degree of stenosis from flow/velocity profiles in peripheral vein bypasses. A Harvard pulsatile flow pump (70 BPM) pumped human blood (HCT, 35-45%) through thin-walled polytetrafluoroethylene (3-6 mm in i.d.) into a variable peripheral resistance maintaining a constant mean blood pressure of 80 mm Hg over a flow range of 0-500 ml/min. A Diasonics DRF400 duplex scanner with a 10-MHz imager and 4.5-MHz Doppler probe was used to image and Doppler the conduits and measure flow through them. Validation of Doppler flow measurements (DF) was performed comparing them with flow measured (MF) by timed collection. PSVST within and pressure drop across a 50% stenosis was measured for each of the conduit's sizes over a range of 0-500 ml/min MF. The results show a good correlation between DF and MF (r = 0.99, P less than 0.001) for the whole range of internal diameters. In each 50% stenosed conduit, PSVST correlated well with MF (r = 0.95, P less than 0.001). Curves were constructed of MF vs PSVST for each 50% stenosed conduit. We conclude that measurement of volumetric flow, conduit diameter, and peak systolic velocity within a vein bypass can objectively predict bypass stenoses of 50% or greater.

Resurrection of the in situ saphenous vein bypass. 1000 cases later

Distal bypasses for the terminal stages of atherosclerotic occlusive disease manifest by chronic limb-threatening ischemia are among the most challenging arterial reconstructive procedures of surgeons today. The length and low flow rates of distal bypasses often exceed the functional limits of synthetic and even free vein grafts. However, the saphenous vein, when used in situ, provides a unique, viable, physiologically active, and hence antithrombogenic endothelial flow surface that is ideally suited for such bypasses. This paper presents the experience of the Albany Medical Center Hospital with the first 1000 in situ bypasses performed by the valve incision method over a 12-year period. Limb-threatening ischemia was the most common indication for surgery (91%). An in situ bypass was attempted in over 95% of unselected limbs and were completed in situ and in toto in 94%. 66% of the bypasses were carried out to the infrapopliteal level, and in more than 50% of the limbs, the distal vein diameter was less than 3.5 mm. The 30-day patency rate was 95%, and the cumulative patency rates, by life table analysis at 1, 2, 3, 4, and 5 years, were 90%, 86%, 84%, 80%, and 76%, respectively. The vein diameter, specific outflow vessel, level of distal anastomosis (length of bypass), inguinal inflow source used, and instrumental evolution had no significant effect on immediate or long-term bypass performance.

Durability of the tibial artery bypass in diabetic patients

Infrapopliteal bypass in diabetic patients has been associated with lower rates of patency and limb salvage than in nondiabetic patients. We prospectively compared the patency and limb salvage rates of in situ tibial artery bypass in diabetic and nondiabetic patients. Of 681 in situ bypasses performed for limb salvage over a 7 year period, 387 (57 percent) were carried out in diabetic patients and 294 (43 percent), in nondiabetic patients. Indications for operation most commonly included gangrene or ulceration (74 percent of the diabetic group and 49 percent of the nondiabetic group). Otherwise, the two patient groups were similar. Cumulative patency rates at 1 and 5 years were similar (91 and 74 percent for diabetic patients and 90 and 76 percent for nondiabetic patients, respectively). Limb salvage rates were also not significantly different (96 and 86 percent at 1 and 5 years, respectively, for diabetic patients and 99 and 94 percent, respectively for nondiabetic patients). Despite the unfavorable pattern of atherosclerosis in diabetic patients, the results of tibial arterial reconstructions showed patency and limb salvage rates similar to those seen in nondiabetic patients.

Renal artery intimal flaps after blunt trauma: indications for nonoperative therapy

After sustaining blunt abdominal trauma, two patients were found to have intimal flaps in extrahilar renal arteries without thrombosis. These renal artery injuries were observed without surgical repair because of severe concomitant multiple organ trauma. Continued patency of the renal arteries was confirmed by sequential renal scans or arteriograms. To decrease the risk of morbidity and death after blunt renovascular trauma, a patent artery with an intimal flap may be observed. Mandatory urgent repair is reserved for patients with bilateral renal injuries or for patients with a solitary kidney. Should symptomatic renal infarction or hypertension develop, delayed renal artery repair or nephrectomy is indicated.

Improved operative exposure of infrapopliteal vessels in combined vascular and orthopedic injuries

In a series of six patients, a single-bar anterior external fixator was used to treat combined vascular and orthopedic injuries of the leg. This method of external fixation facilitated operative vascular exposure without sacrificing bony stability or alignment. It may be the preferred method of external fixation for these complex injuries.

Disseminated atheroembolism from extensive degenerative atherosclerosis of the aorta

The surgical management of disseminated atheroembolism was studied in seven patients. The diagnosis of disseminated atheroembolism from extensive degeneration of the thoracic and abdominal aorta was based on clinical evidence of cutaneous atheroembolism, angiographic demonstration of irregular aortic plaques, and findings of cholesterol emboli in tissue specimens. All patients had severe cardiopulmonary disease. In four cases treatment consisted of palliative axillobifemoral bypass with ligation of the external iliac arteries to exclude the proximal aortic source of emboli to the feet. Three patients underwent intestinal resection for visceral atheroembolism. Permanent access for hemodialysis was required in four patients. All patients died within 6 months of the diagnosis of disseminated atheroembolism. Surgical therapy has three roles in disseminated atheroembolism: prevention of further atheroembolism with its attendant peripheral or visceral organ damage; amputation or resection of irretrievably damaged tissue; and provision of chronic hemodialysis access. The optimal treatment is thoracoabdominal reconstruction of the aorta. In the high-risk patient, axillobifemoral bypass with iliac ligation may be used to treat recurrent painful atheroembolism to the feet. Continuing atheroembolism to the visceral and pelvic circulation, renal failure, and progressive asthenia are associated with the poor prognosis of patients with this disease.

Tension pneumopericardium following penetrating chest injury

A 28-year-old male developed tension pneumopericardium following penetrating paraxiphoid injury to the pericardial space. We found no previous reports of this unique problem. Pneumopericardium associated with penetrating chest trauma warrants thorough exploratory surgery to rule out direct cardiac injury.

Management of common femoral artery occlusion. A report of ten cases

Complete occlusion or high-grade stenosis of the common femoral artery (CFA) occurs infrequently, whether as an isolated lesion or associated with similar lesions in other arteries. Ten patients with this condition comprise this report. Three had severe claudication, while seven required treatment for limb salvage. Two of the patients with claudication and one with critical ischemia had isolated CFA lesions. The remaining seven had CFA disease in tandem with either inflow aortoiliac disease or associated distal occlusions. Physical examination and vascular laboratory studies failed to suggest the diagnosis in every instance. Angiography was definitive in revealing the location and extent of pathology. Patients with localized disease were treated by patch angioplasty, balloon dilatation, or by graft replacement and profundaplasty. All others required more extensive reconstructions, with important variations from standard technique being necessary because of the CFA lesion. Amelioration of symptoms was achieved in all patients.

Clinical experience with the multiple lumen central venous catheter

One hundred four multiple lumen central venous catheters (MLC) were evaluated in 74 seriously ill patients. Eighty percent of the catheters were placed in an intensive care unit. Each MLC served as access for a mean of 4.5 different functions, including infusions, central venous monitoring and phlebotomy. Complications occurred with 16 MLC (15.4%), including two aberrant placements, 10 mechanical problems, and four septic catheters (3.8%). Simultaneous administration of TPN and other infusions through MLC did not affect the rate of catheter sepsis. MLC are well tolerated and cost effective. They increase the comfort of patients who require complex venous access or who lack peripheral veins. They allow safe concurrent administration of TPN, medications, and central venous monitoring.

New options for central venous access in cancer chemotherapy. Multiple lumen catheters

New technology has allowed the creation of single catheters with up to four separate luminal channels for access to the central venous system. Since cancer chemotherapy may be associated with local complications specifically related to the mode of intravenous administration, temporary central venous access with a multiple lumen catheter (MLC) offers distinct theoretical advantages over previously used peripheral venous sites. As part of a prospective study to evaluate the clinical efficacy of MLC, the authors have separately studied the usefulness of these catheters in providing venous access to patients receiving chemotherapy.

Effect of aspirin and dipyridamole on the patency of lower extremity bypass grafts

Recent clinical studies indicate that the use of aspirin and dipyridamole improves graft patency rates in patients with infrainguinal polytetrafluoroethylene (PTFE) grafts and aortocoronary vein grafts. We undertook a prospective, double-blind, randomized study to determine whether these drugs administered postoperatively to patients with PTFE or autologous vein infrainguinal bypasses would improve graft patency during the first 24 months after operation. Patients received either aspirin 325 mg and dipyridamole 75 mg or identical placebo tablets three times a day, taken orally. Patency rates were compared by computing standard life tables and comparing cumulative patency rates. One hundred patients with 102 grafts were studied. The cumulative patency rate at 24 months was not significantly different for the treatment (57%) versus control (67%) groups or for any subgroup. We conclude that aspirin and dipyridamole administered postoperatively in the doses used in this study do not improve the overall patency rates of vein or PTFE infrainguinal bypass grafts.

Vascular surgical data registries for small computers

Recent designs for computer-based vascular surgical registries and clinical data bases have employed large centralized systems with formal programming and mass storage. Small computers, of the types created for office use or for word processing, now contain sufficient speed and memory storage capacity to allow construction of decentralized office-based registries. Using a standardized dictionary of terms and a method of data organization adapted to word processing, we have created a new vascular surgery data registry, "VASREG." Data files are organized without programming, and a limited number of powerful logical statements in English are used for sorting. The capacity is 25,000 records with current inexpensive memory technology. VASREG is adaptable to computers made by a variety of manufacturers, and interface programs are available for conversion of the word processor formated registry data into forms suitable for analysis by programs written in a standard programming language. This is a low-cost clinical data registry available to any physician. With a standardized dictionary, preparation of regional and national statistical summaries may be facilitated.

The fate of bypass grafts to an isolated popliteal artery segment

From 1967 to 1982, 55 patients underwent 64 femoropopliteal bypass grafts into an isolated popliteal artery segment. Seventy-six percent of these patients had threatened limb loss from advanced atherosclerosis, and 24% had disabling claudication. Forty-five percent of the patients were diabetic. The 30-day operative mortality rate was 1.6%, and the 30-day postoperative amputation rate was 3.2%. Graft potencies were analyzed by the life table method. The 2-year graft patency rate was 70.6%, and the 5-year patency was 60.7%. The 2- and 5-year limb salvage rates were each 83%. With evidence for decreased graft function, four grafts (6%) were successfully revised before failure occurred. Among 10 polytetrafluoroethylene grafts followed up to a maximum of 48 months, there was one early postoperative occlusion, one long-term occlusion, and one early amputation. With respect to patency and limb salvage, the results of isolated popliteal artery segment grafts fall between the 5-year patency and limb salvage rates for autogenous vein grafts to popliteal arteries with at least one tibial vessel runoff (78% patency and 89% limb salvage) and the rates for femoral-tibial/peroneal grafts (5-year patency 56%, limb salvage 69%). An isolated segment is an appropriate recipient vessel for a reconstruction for limb salvage, and reasonably good results can be anticipated.