Three-year outcome of endovascular treatment of superficial femoral artery occlusion.

HYPOTHESIS: Patency after primary percutaneous transluminal angioplasty (PTA) and stenting of superficial femoral artery (SFA) occlusions is better than historical experience with PTA alone. DESIGN: Consecutive case series of primary PTA with stenting, and follow-up with duplex imaging every 6 months (mean +/- SD follow-up, 32 +/- 15 months). SETTING: Veterans Affairs medical center. PATIENTS AND METHODS: Patients were 57 previously untreated men with 71 limbs having chronic atherosclerotic SFA occlusion with suprageniculate reconstitution and patent tibial runoff. Critical ischemia (Society for Vascular Surgery [SVS] category, 4-6) was present in 7 (10%), the remainder had intermittent claudication only (SVS, 1-3). INTERVENTIONS: Guidewire recanalization followed by PTA, Wallstent deployment, and adjunctive thrombolysis as necessary; 19 limbs (27%) required thrombolysis to manage periprocedural thrombosis. MAIN OUTCOME MEASURES: Cumulative patency, limb salvage, and complications. RESULTS: Length (mean +/- SD) of occlusion was 14.4 +/- 9.9 cm. Length of stented artery was 24.3 +/- 11.1 cm. Ankle brachial index increased from 0.59 +/- 0.14 to 0.86 +/- 0.16 (P<.001) after stenting. One- and 3-year patencies were as follows: primary, 54.6% +/- 6.3% and 29.9% +/- 6.6%; assisted primary, 72.3% +/- 5.6% and 59.0% +/- 6.8%; and secondary, 81.6% +/- 4.8% and 68.3% +/- 6.5%. Three-year secondary patency when periprocedural thrombolysis was required was 35.7% +/- 12.5% compared with 70.6% +/- 7.4% for limbs not requiring periprocedural thrombolysis (P=.02); the differences in occlusion length and severity of ischemia were not significant between these 2 groups. Limbs undergoing adjunctive PTA during angiography 6 to 12 months after initial stenting had 63.0% +/- 13.3% patency at 3 years compared with 100% patency in limbs not requiring PTA at 6 to 12 months angiography (P=.046). Periprocedural mortality and morbidity were 2.8% and 15.5%, respectively. Three of the 7 limbs with critical ischemia underwent amputation during follow-up compared with 2 (3%) of 64 limbs with functional ischemia (chi(2) test, P<.006). A mean of 1.8 endovascular interventions per limb were performed. CONCLUSIONS: Percutaneous transluminal angioplasty and stenting yielded higher patency rates than historical controls undergoing PTA alone. When periprocedural thrombolysis is required, subsequent patency appears to be significantly worse. Poor results after PTA and stenting of limbs with critical ischemia and the need for additional endovascular therapy limit the technique's utility.

Angioplasty and stent placement in chronic occlusion of the superficial femoral artery: technique and results.

PURPOSE: To improve the patency rate for angioplasty in chronic occlusion of the superficial femoral artery by deploying stents after angioplasty. MATERIALS AND METHODS: Angioplasty and stent placement were performed in 61 arteries in 48 male patients. The mean occlusion length was 13.5 cm and the mean stent length was 30 cm. Patency rates were analyzed at 6 months and at 1, 2, 3, and 4 years. The predictors of restenosis were analyzed by univariate and multiple logistic regression. RESULTS: Patency rates were 87% at 6 months, consisting of 74% primary, 6% primary assisted, and 7% secondary; 79% at 1 year, consisting of 47% primary, 19% primary assisted, and 13% secondary; 72% at 2 years, consisting of 36% primary, 26% primary assisted, and 10% secondary; 70% at 3 years, consisting of 26% primary, 22% primary assisted, and 22% secondary; and 63% at 4 years, consisting of 25% primary, 0% primary assisted, and 38% secondary. There was a 15% morbidity rate and one mortality as a result of retroperitoneal bleeding. Better patency rates were noted at all time intervals in diabetic limbs, 7-mm-diameter versus 10-mm-diameter stents, shorter obstructions and shorter stents, nonsmokers, in limbs in which urokinase was not necessary after stent deployment, and in limbs with an International Society of Cardiovascular Surgery (ISCVS) classification under 3. Patency rates were not affected by age, race, number of trifurcation vessels patent, experience in performing the procedures, and procedures requiring less time. By multivariate logistic analysis, the independent predictors of patency at 6 months were postprocedure ankle/brachial index (ABI) and shorter stent length; at 1 year, preprocedure ABI, shorter stent length, and the presence of diabetes; at 2 years, preprocedure ABI and the presence of diabetes; and at 3 years, the preprocedure ABI. CONCLUSIONS: The techniques used to reestablish antegrade flow in these superficial femoral arteries yielded a high success rate. In addition, the use of angioplasty with stents may improve patency rates over angioplasty without stents.

Pulmonary vascular pressures increase after lung volume reduction surgery in rabbits with more severe emphysema.

BACKGROUND: Emphysema is a chronic disease of the lungs with destruction of terminal alveoli and airway obstruction. Lung volume reduction surgery (LVRS) is being investigated for the treatment of emphysema. Increasing resection volumes with LVRS may lead to worsening of carbon monoxide diffusing capacity (Dlco) despite improvement in compliance and flow. We hypothesized that the pulmonary circulation-related parameters, pulmonary artery pressure (PAP) and diffusing capacity (Dlco), may be used as indicators of the maximally tolerated LVRS resection volume. METHODS: Emphysema was induced in 55 rabbits by endotracheal nebulization, with either single 15,000-unit (mild emphysema) or three 11,000-unit (moderate emphysema) doses of elastase. At Week 6, bilateral LVRS was performed via median sternotomy with an endoscopic stapler. Single-breath Dlco, static compliance, and PAP were measured prior to emphysema induction, preoperatively, and 1 week following LVRS. Animals were divided into the following groups: Group I (mild emphysema, <3 g resected), group II (mild emphysema, >3 g resected), group III (moderate emphysema, <3 g resected), group IV (moderate emphysema, >3 g resected). RESULTS: All animals having LVRS had immediate postoperative increase in pulmonary vascular resistance (PVR) following lung resection. Mean PAP, however, remained elevated when measured 1 week after LVRS (sacrifice) in animals with moderate emphysema. This is in contrast to animals with mild emphysema, in which follow-up PAPs approached preoperative baseline. CONCLUSION: These finding suggests that sustained increased PVR, denoted by elevated PAP, is more likely to occur after LVRS in animals with more severe emphysema and larger volume resection. The spirometric and compliance benefits of greater resection volumes have to be weighed against the compromise in pulmonary vasculature in the effort to determine the ideal resection volume for various degrees of emphysema.

Pulmonary artery pressure: an intraoperative guide to limiting resection volume.

Lung volume reduction surgery (LVRS) has shown promising results in severe emphysema. However, intraoperative indicators are needed to define optimal resection volumes. Diffusing capacity (DLCO) worsens with larger LVRS and may correlate with pulmonary artery (PA) pressure. We hypothesized that there would be a greater increase in PA pressures with larger volume LVRS in an inhaled elastase animal emphysema model. Twenty-one rabbits were induced with 15,000 units of elastase via an endotracheal tube. Four weeks later, bilateral LVRS was performed through a median sternotomy using an endoscopic stapler. PA pressures were measured prior to LVRS, immediately after LVRS, and at sacrifice. Single-breath DLCO, static pressure-volume relationships, and forced expiratory flows were measured prior to induction and at corresponding times to PA pressures. Systolic PA pressures increased in both groups immediately after LVRS (small: 2. 67 +/- 9.2 mm Hg, ANOVA, P = 0.023; large: 3.8 +/- 8.5 mm Hg, P = 0. 002), and then decreased at time of sacrifice 1 week later (small: 9. 43 +/- 4.8 mm Hg, ANOVA, P = 0.053; large: 5.2 +/- 7.3 mm Hg, P = 0. 552). The decrease, at sacrifice, in PA pressures was greater for small LVRS animals than large LVRS animals. The mortality rate (MR) for the small resection group was 0%, whereas that for the large resection group was 24%. The MR associated with larger LVRS was appreciably greater than that associated with small LVRS. These studies suggest that PA pressures may prove to be a useful intraoperative indicator for limits of resection.

Effect of lung volume reduction surgery on pulmonary diffusion capacity in a rabbit model of emphysema.

BACKGROUND: While there is renewed interest in lung volume reduction surgery (LVRS) for treatment of emphysema, many aspects of the operation such as patient selection and surgical end points of excision are uncertain. We studied the effects of LVRS on measured lung volumes and diffusion capacity in an animal model to investigate optimal resection volumes. METHODS: Emphysema was induced in 32 New Zealand white (NZW) rabbits using aerosolized elastase. Helium dilution lung volumes and single breath DLCO were measured concurrently at baseline, following induction of emphysema (preop), and 1 week postoperatively (postop) following LVRS. Bilateral upper and middle lobe stapled lung resections were performed through midline sternotomies with excision of variable amounts of lung tissue from 1.8 to 5.8 g. RESULTS: FRC increased following induction of emphysema and decreased postoperatively. DLCO improved with increasing lung tissue resection up to 3 g of tissue and then decreased as even greater amounts were removed (r = 0.54). CONCLUSIONS: Measured lung volumes increase with development of emphysema and appropriately decrease in response to LVRS in this rabbit model. DLCO improves with moderate resection but then decreases with excessive excision of lung quantities and may help define one physiologic operative end point. In this rabbit model, excision of approximately 30% of lung volume was optimal and prevented further decrease in diffusion capacity.

Surgical management of coronary arterial disease in the elderly.

Coronary artery angioplasty or bypass is being performed for increasing numbers of patients in their seventh, eighth, ninth and even tenth decades of life. Because of the cost involved, justification for performing these procedures in the elderly has become a topic of daily discussion among those responsible for funding healthcare. Both silent and overt coronary artery disease (CAD) are more common in the population over 65 years of age. Because CAD in the elderly often presents in an atypical manner, diagnosis of the disease is frequently delayed. Partly because of the delayed diagnosis and partly because of cost considerations, coronary arterial bypass (CABG) is more often performed as an emergency procedure in the elderly with the results that both operative mortality and costs are increased over those observed in a younger population. Nevertheless, it is clear that performance of coronary revascularization procedures in the elderly can both prolong life and improve the quality of life beyond what can be achieved using alternative methods of treatment. Greater efforts directed toward detection of ischemic heart disease in the these patients and earlier, elective surgery could significantly reduce both the mortality and disability associated with CAD in the elderly.

Redistribution of blood flow after carotid endarterectomy.

PURPOSE: We wanted to characterize the immediate effect of endarterectomy on flow of the arteries composing the extracranial carotid artery system. METHODS: Transit time ultrasound probes were used to measure flow through the carotid bifurcation in 48 patients undergoing endarterectomy. Maximum single-diameter stenosis affecting the internal carotid artery (ICA) was determined by angiography. The significance of differences between means were determined by t tests and analysis of variance; linear and nonparametric correlation analyses were also applied to analyze the relation between stenosis and several flow-derived parameters. RESULTS: Common carotid artery flow significantly increased (p = 0.0043) from a mean value of 264 +/- 99 ml/min to 314 +/- 98 ml/min, corresponding to an average percent increase of 34.3% +/- 71.3%. ICA flow increased from 128 +/- 69 ml/min to 173 +/- 66 ml/min (p < 0.0001), with an average percent increase of 74.9% +/- 114.9%. External carotid artery (ECA) flow decreased from 129 +/- 61 ml/min to 106 +/- 49 ml/min (p = 0.0098), representing an average percent decrease of -5.2% +/- 48.2%. The difference between ECA and ICA mean flow changes is highly significant (p < 0.001). The percent change in ECA flow did not correlate with preoperative stenosis. We noted, however, a positive correlation between stenosis and the ECA/ICA flow ratio before endarterectomy (Spearman r = 0.31, p = 0.032), indicating that more severe stenosis led to a greater distribution of blood into the ECA. The ECA/ICA flow ratio fell from an initial value (ECFbef/ICFbef) of 1.52 +/- 1.74 before endarterectomy to 0.69 +/- 0.37 (ECFaft/ICFaft) after endarterectomy (p = 0.0006). CONCLUSIONS: The data are consistent, with the ECA being an important collateral path for cerebral perfusion when ICA stenosis exists. When endarterectomy relieves bifurcation stenosis, common carotid artery blood flow is redistributed preferentially to the ICA at the expense of ECA flow, consistent with a change in the relative resistances of the two vessels resulting from operative reconstruction.

Inguinal wound fluid collections after vascular surgery: management by early reoperation.

Inguinal wounds complicated by significant fluid collections after vascular grafting procedures were managed by exploration soon after recognition in 14 patients. Within 24 hours, incisions were reexplored, fluid collections were evacuated and cultured, and closed suction drains were placed. The wound was reapproximated, and broad spectrum antibiotics were given intravenously until 24 hours after removal of the drain. Variables evaluated included spontaneous drainage before exploration, positive intraoperative wound cultures, exposure of graft when the wound was opened, and type of graft used. On careful follow-up, from 5 months to 3.5 years, averaging 14 months, only one patient had an infected graft, occurring 6 months after the wound exploration. There were no complications in wound healing from the inguinal explorations. These results suggest that early exploration and reclosure of clinically significant postoperative fluid collections is safe, results in primary healing, and has a low rate of subsequent graft infection.

Changes in internal carotid blood flow after carotid endarterectomy correlate with preoperative stenosis.

BACKGROUND: The relationship between preoperative stenosis and the effect of carotid endarterectomy (CEA) upon internal carotid blood flow (ICF) is not well understood. With the intention of better characterizing this, we compared intraoperative measurements of internal carotid blood with the maximum single diameter stenosis found in preoperative angiograms. METHODS: Fifty-two patients undergoing 64 carotid endarterectomies (12 bilateral) had transit-time ultrasound perivascular probes used to measure ICF before and after CEA, and the percent change in ICF (% delta ICF) achieved was calculated. Maximum single-diameter stenosis was determined by comparing the least diameter in the flow path from the common carotid to the normal-appearing internal carotid just distal to bifurcation disease. RESULTS: The entire group had a mean of 53 +/- 21% stenosis found on preoperative angiograms, and % delta ICF averaged 64 +/- 92%. When divided into subgroups based on degree of stenosis, patients with 0% to 40% stenosis (n = 17) had % delta ICF of 32 +/- 46%, patients with 41% to 70% stenosis (n = 30) had % delta ICF of 72 +/- 105%, and patients with more than 70% stenosis had % delta ICF of 168 +/- 160%. The differences in % delta IC were significant for the > 70% group compared with the other groups (analysis of variance, P < 0.005), and marginally significant (P = 0.056) between the 0% to 40% and the 41% to 70% groups. The scatter plot of % delta ICF versus stenosis showed a significant second order direct correlation (r = 0.428, P < 0.001) and disproportionate increases in ICF above 60% stenosis. CONCLUSION: A curvilinear relationship between stenosis and immediate increase in ICF after CEA was demonstrated in agreement with theory, and in those patients with more than approximately 60% single-diameter stenosis, large disproportionate increases in blood flow were more frequently observed.

Noninvasive cardiac output: simultaneous comparison of two different methods with thermodilution.

The authors attempted to simultaneously measure cardiac output by thermodilution (COtd), thoracic bioimpedance (CObi), and suprasternal Doppler ultrasound (COdopp) in 68 patients. Subgroups separately compared included patients whose lungs were mechanically ventilated, patients undergoing cardiac surgery, aortic surgery, patients with dysrhythmias, and patients with sepsis. The authors also studied the value of the ventricular ejection time (VET) in evaluating the agreement of CObi and COdopp with COtd. Simultaneous CObi and COtd were available in a total of 56 patients (416 data sets) with an overall correlation coefficient r = 0.61, regression slope (m) of 0.52, intercept (y) of 2.46, and mean (CObi-COtd) difference (bias) of -0.67 +/- 1.72 (SD) l/min. Simultaneous COdopp and COtd were available in 59 patients (446 data sets) with an overall r = 0.51, m of 0.53, y of 2.05, and bias of -0.79 +/- 1.95 l/min. CObi agreed most closely with COtd in patients whose lungs were mechanically ventilated, who had not undergone cardiac or aortic surgery, and with VET difference less than 40 ms (16 patients, 99 data sets; r = 0.74; m = 0.97; y = 0.15; bias = -0.02 +/- 1.53 l/min). COdopp agreed most closely with COtd in patients whose lungs were mechanically ventilated, who had not undergone cardiac or aortic surgery, and in sinus rhythm with VET difference less than 40 ms (10 patients, 45 data sets; r = 0.82; m = 0.98; y = -0.07; bias = -0.82 +/-1.03 l/min). VET by radial artery can help evaluate the reliability of CObi and COdopp.

Asymptomatic peptic disease in patients undergoing major elective operations: a prospective endoscopic study.

Postoperative bleeding is usually attributed to stress ulcers; however, occult preoperative lesions could also be responsible. To determine their frequency and nature, we prospectively examined 72 patients endoscopically prior to major elective operations. Entry criteria included a planned stay in the Surgical Intensive Care Unit, greater than 2 days, and a negative history, physical examination, and stool guaiac. Gastric and duodenal mucosae were scored separately, using a 0- to 7-point scale. Scores were graded negative (0), hyperemia (1), gastroduodenitis (2-5), mucosal erosions (6), and ulcers (7). Erosions or ulcers were found in 14% of patients and gastroduodenitis is an additional 10%. We found that none of the 27 risk factors or any combination of factors tested correlated with ulcers, erosions, or gastroduodenitis. Thus, patients with asymptomatic gastroduodenal erosions or ulcerations could not be identified preoperatively, except by endoscopy. Until the significance of these lesions as cause of postoperative bleeding is determined, we recommend routine postoperative gastric pH titration with antacids for patients undergoing major elective operations.

Computer-derived equations for predicting survival postoperatively. Their usefulness and limitations.

We used multivariate analysis to determine whether survival following perforations of the gastrointestinal tract could be accurately predicted from preoperative data. Of 12 variables tested, four were found to have predictive value. These were age, pulmonary disease, preoperative shock, and the attending surgeon. When these four variables were employed in a logistic regression equation on 42 patients, it correctly predicted which 21 patients died before leaving the hospital. To produce an equation useful for other hospitals, we recalculated it without the attending surgeon variable. Again, the equation was used to predict survival. The correlation of predicted vs observed outcome remained high, and, using a 2 x 2 chi 2 test, the correlation was significant. We then cross validated the three-variable model on data from a second hospital. The model accurately predicted the new data equally well. We believe that predictive models can identify risk factors in a variety of patient populations and can determine who is likely to benefit from specific treatment modalities.

Hepatic trauma during cardiac surgery.

Two patients undergoing routine cardiac surgical procedures developed hypovolemic shock following cardiopulmonary bypass. They were found to have hemoperitoneum due to liver injuries. In the first case, intraabdominal hemorrhage was not diagnosed soon enough to save the patient. In the second case, immediate abdominal exploration led to prompt repair of the injury and resuscitation of the patient. We suggest that unexplained hypovolemic shock following cardiopulmonary bypass should be evaluated by immediate abdominal exploration to rule out hemoperitoneum.

Pharmacokinetics of 5-fluorouracil during hyperthermic pelvic isolation-perfusion.

The pharmacokinetics of 5-fluorouracil (5-FU) injected into a surgically isolated pelvic circuit during hyperthermic perfusion was studied in five patients with local recurrence of anorectal cancer. 5-FU doses ranged from 11 to 23 mg/kg. The geometric mean ratio of peak plasma 5-FU in the isolated to systemic circuits was 10, the ratio at the end of the 45-minute perfusion was 12.5. The mean half-life of 5-FU in the isolated circuit was 18.5 minutes. Total drug exposure for the isolated circuit was 7.8-fold greater than for the systemic compartment. These results demonstrate a large pharmacologic advantage for the use of the isolation-perfusion technique.

Operative risk factors associated with unstable angina pectoris.

We performed a prospective study in 207 patients with unstable angina pectoris (UA) to identify factors associated with operative mortality (OM) and perioperative myocardial infarction (MI) from myocardial revascularization. The OM was 3.9% (8/207) and the incidence of MI was 11% (23/207). Clinical variables (age, prior MI, electrocardiographic evidence, symptoms, left ventricular function) and operative variables (incomplete revascularization, cardiopulmonary bypass time, cross-clamp time) did not correlate with OM or MI. Operative mortality was associated with critical triple-vessel disease, but not left main coronary artery disease, and accounted for seven of the eight deaths (P less than .01). Myocardial infarction was associated with elective surgery (22/167) as opposed to urgent surgery (1/40) (P less than .01). Therefore, patients with critical triple-vessel disease are the highest risk group for OM, and urgent operation seems to reduce the incidence of MI in patients with UA.

Fragmentation of a Celestin tube causing intestinal obstruction. Case report and review of the literature.

Current management of benign and malignant esophageal lesions has changed little in the past 25 years. Treatment of unresectable lesions has consisted primarily of exclusion and bypass procedures as well as prosthetic intubations for relief of dysphagia. A case of a Celestin tube fragmentation in a patient with unresectable esophageal carcinoma causing small bowel obstruction is presented. Diagnosis, management, and review of the literature are discussed. Recommendations for use of the Celestin tube in patients with good long-term prognoses include keeping a high index of suspicion for possible complications, close and regular radiographic and endoscopic follow-up, and early surgical intervention upon tube fragmentation.

Control of pelvic cancer with hyperthermic isolation-perfusion.

Eight patients with refractory pelvic cancer were treated with a technique of hyperthermic pelvic isolation-perfusion (rectosigmoid colon 7, bladder 1). The procedure was successful in achieving regional hyperthermia in all patients. All five patients experiencing severe pelvic pain prior to surgery had resolution of pain, although in one patient this relief was transient. Five patients had additional intraabdominal procedures at the time of laparotomy to control unsuspected foci of recurrent cancer. There were no operative deaths. Five complications occurred in four patients although only one was considered life threatening (fracture of aorta at the time of cross-clamping). Sloughing of necrotic tumor occurred between 1 and 2 weeks postperfusion and at times was dramatic. The efficacy of this technique is impressive and it is suggested that it be utilized earlier in the course of disease in patients with uncontrolled pelvic cancer.