Preoperative spirometry predicts perioperative pulmonary complications after major vascular surgery

This study determined utility of preoperative spirometry for prediction of postoperative pulmonary complications (PPC) defined as pneumonia, ventilator dependence greater than 48 hours, and adult respiratory distress syndrome in 147 patients undergoing vascular surgery from June 1988 through March 1990 [39 aortic aneurysm repairs, 21 carotid procedures, and 87 operations for occlusive disease including aorto-ileofemoral, infra-inguinal, and visceral]. The incidence of PPC was 12.9 per cent, while cardiac complications (myocardial infarction, congestive heart failure, and ventricular arrhythmias) were present in 9.8 per cent. Prior or current smoking, which was present in 80 per cent, was not predictive of PPC. FEV1 was 2.2 +/- 0.7 L/s (mean +/- 1 SD). Abnormal FEV1 (2.0 or less L/s) was present in 42 per cent (n = 62). For FEV1 of 2.0 or less, PPC rate was 22.5 per cent versus 5.8 per cent for FEV1 greater than 2.0 L/s (P less than 0.005, Fisher exact). The incidence of PPC was 30.7 per cent for aortic aneurysm repair, 8.0 per cent for occlusive disease, and 4.7 per cent for carotid procedures. Abdominal aortic procedures (performed in 67 patients: 39 for aortic aneurysm repair and 28 for aortoiliac occlusive disease) were associated with a PPC rate of 22.4 per cent versus 5.0 per cent for "nonabdominal" procedures (P less than 0.002, Fisher exact). Life table analysis after surgery demonstrated decreased survival for patients with PPC (P = 0.031, Mantel-Haensel) during follow-up (250 +/- 165 days). PPC are associated with abnormal FEV1 and abdominal vascular procedures. In conclusion, preoperative spirometry is useful for the prediction of PPC after vascular surgery.

Trauma to the proximal superior mesenteric artery: a case report and review of the literature

Visceral arterial injuries account for a small but important portion of major abdominal vascular trauma. A case of proximal superior mesenteric artery trauma is presented. The advantages and drawbacks of the surgical approaches to these injuries are discussed. On the basis of a review of the literature describing the management of these injuries, ligation of the proximal superior mesenteric artery for trauma cannot be recommended. Prompt surgical intervention with revascularization offers the best chance for the survival of these critically injured patients.

Thallium redistribution does not predict perioperative cardiac complications following vascular surgery

Utility of preoperative stress thallium scintigraphy (STS) was determined in 59 patients, thought to be at increased risk, prior to major vascular surgery from July 1987 to February 1990. Forty-seven had oral dipyridamole and 12 underwent exercise STS. Thallium redistribution (TR) was present in 61% (n = 36); fixed defects were present in 59% (n = 35); and some combination of defects was present in 76% (n = 45). Perioperative cardiac complications (CC = congestive heart failure [n = 3], ventricular arrhythmia [n = 2], and MI [n = 1]) were present in 8.5% (6 CC in 5 patients). Incidence of CC was 8.3% (3/36) in those with TR, and 8.7% (2/23) without TR (relative risk = 0.95). Perioperative MI was present in 2.8% (1/36) with TR vs. 0% (0/23) without. Though mortality was 3.4%, no perioperative deaths were from cardiac disease. Utility of STS is not clearly established for prediction of perioperative cardiac risk after major vascular surgery.

Intimal hyperplasia is reduced by ornithine decarboxylase inhibition

Polyamines are intracellular cations that are thought to play a role in the regulation of cell growth and differentiation. This study was undertaken to determine if inhibition of ornithine decarboxylase (ODC), the rate-limiting enzyme of polyamine synthesis, suppresses formation of intimal hyperplasia (IH) after arterial injury. Twenty New Zealand white rabbits underwent balloon catheter deendothelialization of a common carotid artery. Treated animals (n = 10) were given alpha-difluoromethylornithine (DFMO), an inhibitor of ODC, ad lib in drinking water as a 2% solution. DFMO was begun 3 days prior to surgery and continued until vessel harvest. Vessels were perfusion-fixed at harvest, 2 (n = 10) and 4 (n = 10) weeks postoperatively. All arteries remained patent. There were no histologic differences in the IH between treated and untreated animals. The intima and media surface areas on serial arterial cross sections were determined using computer-assisted planimetry. There was a significant difference in the IH surface area of injured arteries between untreated and DFMO-treated animals at both 2 (17.6 +/- 2.0 vs 3.0 +/- 1.6 microns 2; P less than or equal to 0.001) and 4 weeks 27.4 +/- 5.6 vs 7.1 +/- 1.8 microns 2; P less than or equal to 0.008). No differences were seen in medial thickness. We conclude that ODC inhibition reduces early development of IH after arterial deendothelialization. These data support the hypothesis that polyamines may be cellular messengers involved in the regulation of IH formation.