The role of composite sequential bypass in the treatment of multilevel infrainguinal arterial occlusive disease.

BACKGROUND: In this study, the efficacy of composite sequential bypass is compared to that of standard in situ bypass, and to alternate prosthetic graft systems which have been used for the treatment of multilevel infrainguinal arterial occlusive disease in the absence of suitable autogenous vein. PATIENTS AND METHODS: A retrospective review of graft patency and limb salvage included 197 patients undergoing 211 bypass procedures consisting of in situ femoral-tibial (IS; n = 119); composite sequential (CS; n = 35), prosthetic femoropopliteal with single (PFP-1; n = 30) or no vessel runoff (PFP-O; n = 9), and prosthetic femoral-tibial (PFT; n = 18) bypass. RESULTS: By life-table analysis, IS bypass provided superior primary (P < 0.005) and secondary (P < 0.0005) patency over the other groups. CS bypass was similar to PFP-1, with a 2-two year primary patency of 35% and 44% (NS), respectively, and limb salvage rates of 60% and 80% (P = 0.01). PFP-O and PFT bypass procedures did considerably worse, with a 1-year patency of 19% and 22%, respectively, and associated limb salvage rates of 25% and 41% (NS). CONCLUSIONS: Composite sequential bypass is an acceptable procedure for infrainguinal arterial reconstruction when absence of autogenous vein prevents either in situ or secondary vein graft bypass procedures.

Is deep vein thrombosis surveillance warranted in high-risk trauma patients?

BACKGROUND: Deep vein thrombosis (DVT) has been reported to occur in 20% to 40% of high-risk trauma patients if no prophylaxis is used. The purpose of this study was to determine the incidence of DVT and utility of a screening program in a high-risk group of trauma patients for whom routine DVT prophylaxis was utilized. PATIENTS AND METHODS: Of 3,154 trauma admissions over a 20-month period, 343 patients (10.9%) identified as high risk based on established criteria (prolonged bed rest, Glasgow coma score (GCS) of 7, spinal injury, lower extremity or pelvic fracture) were placed on a prospective surveillance protocol using color-flow duplex scanning and received thromboembolic prophylaxis. RESULTS: Twenty-three thromboembolic complications occurred, including 20 DVTs (5.8%) and 3 pulmonary emboli ([PE] 1%). Univariate analysis showed that the risk of DVT was related to age (52.6 + 19.9 years versus 38.1 + 18.5; P = 0.001), a longer hospital stay (31.4 versus 17.8 days; P = 0.001), or the presence of spinal fracture (12.6% versus 3.5%; P = 0.01). Discriminant function analysis revealed that length of stay, intensive care unit days, age, and GCS allowed correct classification of those who did not develop DVT in 97% of cases but was only correct in 15% of cases in predicting those who would develop DVT. Injury severity score (ISS) was not predictive in this multivariate analysis. Seventeen (85%) DVTs were unsuspected clinically. Study patients received an average of 3.5 studies at an overall charge of $313,330 to detect 17 clinically unsuspected DVTs (5%). This represents about 5% of the total bed charges for these patients, or $18,000 per DVT. CONCLUSIONS: These results suggest that standard use of DVT prophylaxis in a high-risk trauma population leads to a low incidence of DVT and that a screening protocol is effective in detecting unsuspected DVTs. Use of a surveillance protocol, however, may reduce but will not eliminate the incidence of pulmonary emboli in this patient population.

Colonic ischemia: the Achilles heel of ruptured aortic aneurysm repair.

Colonic ischemia is an often fatal complication of abdominal aortic aneurysm (AAA) repair. In elective AAA repair, patency of the inferior mesenteric artery (IMA) has been shown to be an important contributing factor. The purpose of this study was to determine which clinical and operative factors are important in the development of colonic ischemia in ruptured AAA repair. A retrospective review of all patients treated for ruptured AAA over a 7-year period was performed. Of 101 patients who were treated for ruptured AAA, 71 (70 per cent) survived for longer than 24 hours postoperatively, and these patients are the basis for this study. Colonic ischemia, primarily left sided, was a common perioperative complication (n = 24; 35 per cent) requiring colectomy in 11 patients (44 per cent). It carried a 44 per cent mortality compared to 20 per cent in patients without this complication (P = 0.07). Colonic ischemia occurred more frequently in patients with preoperative shock (P = 0.01) and a greater intraoperative blood loss (P = 0.003), but showed no correlation with patient age, co-morbid medical conditions, laboratory values, time to operation, or treatment of the IMA. Most patients with postoperative bowel ischemia were found to have chronic IMA occlusion, including 8 of the 11 patients requiring colectomy. Revascularization would not be feasible in this group. Revascularization of patent IMAs had little effect on outcome. Of the 17 patent IMAs, 9 were reimplanted and 5 (55 per cent) developed bowel ischemia, two of which required colectomy. Eight were ligated and 3 (38 per cent) developed bowel ischemia, one requiring colectomy. The presence of preoperative shock is the most important factor predicting the development of colonic ischemia following ruptured AAA. The incidence of ischemia is not altered by the presence of a patent IMA or with attempts at IMA revascularization. Colonic ischemia remains a significant source of morbidity and mortality in these patients.

Rupture of known abdominal aortic aneurysms: an ethical dilemma.

Elderly patients with abdominal aortic aneurysms (AAA) may be deemed inoperable due to the presence of comorbid conditions. Presentation of these patients with acute rupture can then result in difficult ethical decisions regarding surgical treatment. Over six years, 80 patients were treated emergently for ruptured AAA. Of these patients, 26 (32.5%) had known aneurysms. This study was performed to determine outcome and factors affecting mortality in patients with known AAAs. There were no significant differences between known and unknown AAA groups with regard to operative risk. In the overall group (n = 80), patient delay in seeking treatment averaged 20.4 hours with a trend towards shorter times in those with known AAAs (13.8 hours) compared with the unknown group (23.6 hours; p = 0.09). Medical transport delay, however, was significantly shorter for patients with known AAA (124 minutes versus 230 minutes; p = 0.04). Overall mortality was 56 per cent (n = 45). Those patients with known AAAs had a higher mortality (69%; n = 18) than those with unknown AAAs (50%, n = 27) but this was not statistically significant (P = 0.10). In patients with known AAAs, operative death was related to patient delay, with an average delay in seeking medical advice of 21.3 hours in nonsurvivors compared with 8.6 hours in survivors (P = 0.04). No other risk or demographic factors correlated with mortality. Despite a known AAA, significant delay in seeking medical advice occurred, and this delay resulted in decreased survival. Patient education is imperative if nonoperative treatment is chosen.(ABSTRACT TRUNCATED AT 250 WORDS)

Is the increasing use of prophylactic percutaneous IVC filters justified?

To determine whether the ease of percutaneous inferior vena cava (IVC) filter placement has led to an alteration of procedural indications, we reviewed the medical records of 150 patients who underwent 156 filter insertions from January 1986 through June 1993. Thirty-nine Greenfield filters were surgically inserted, while 117 percutaneous devices were placed in 111 patients. A comparison of these two groups showed that they had similar thromboembolic risks. Indications for surgical filter placement included pulmonary embolism (PE) prophylaxis (23%), PE with a contraindication to anticoagulation therapy (28%), and complication (26%) or failure (20%) of anticoagulation therapy. Indications for initial percutaneous placement included PE prophylaxis (56%), PE with a contraindication to anticoagulation therapy (27%), and complication (7%) or failure (9%) of anticoagulation therapy. Early mortality in the surgical and percutaneous groups was 26% and 27%, respectively. Ten percent of early deaths in the surgical group and 50% in the percutaneous group were associated with prophylactic insertions (P = 0.032). Associated morbidity was 8% in the surgical versus 24% in the percutaneous group (P = 0.036). The unrestricted use of prophylactic percutaneous IVC filters appears to have resulted in an increased procedure-related morbidity with no clear benefit in early patient survival. These findings suggest a need for improved patient selection.