John H. Lemmer

Aprotinin for Primary Coronary Artery Bypass Grafting: A Multicenter Trial of Three Dose Regimens

BACKGROUND High-dose aprotinin reduces transfusion requirements in patients undergoing coronary artery bypass grafting, but the safety and effectiveness of smaller doses is unclear. Furthermore, patient selection criteria for optimal use of the drug are not well defined. METHODS Seven hundred and four first-time coronary artery bypass grafting patients were randomized to receive one of three doses of aprotinin (high, low, and pump-prime-only) or placebo. The patients were stratified as to risk of excessive bleeding. RESULTS All three aprotinin doses were highly effective in reducing bleeding and transfusion requirements. Consistent efficacy was not, however, demonstrated in the subgroup of patients at low risk for bleeding. There were no differences in mortality or the incidences of renal failure, strokes, or definite myocardial infarctions between the groups, although the pump-prime-only dose was associated with a small increase in definite, probable, or possible myocardial infarctions (p = 0.045). CONCLUSIONS Low-dose and pump-prime-only aprotinin regimens provide reductions in bleeding and transfusion requirements that are similar to those of high-dose regimens. Although safe, aprotinin is not routinely indicated for the first-time coronary artery bypass grafting patient who is at low risk for postoperative bleeding. The pump-prime-only dose is not currently recommended because of a possible association with more frequent myocardial infarctions.

Aprotinin for coronary artery bypass grafting: Effect on postoperative renal function

Two hundred sixteen patients undergoing coronary artery bypass graft procedures were randomized to receive either high-dose aprotinin or placebo. Clinically important postoperative renal insufficiency was infrequent, with a single patient (0.9%) from each group requiring dialysis. Although increases in the serum creatinine level occurred postoperatively in more patients who received aprotinin (20/108) than in those given placebo (13/108), the difference between the two groups was not statistically significant (p = 0.186), and the increases were generally small and transient. Likewise, there was no difference between the groups in terms of the incidence of abnormal serum electrolyte levels, blood urea nitrogen levels, or urinalysis findings, or in the frequency of abnormal creatinine clearance rates. Under the conditions described, aprotinin use does not appear to be associated with a significant risk of serious renal toxicity.

Coronary Artery Spasm Following Coronary Artery Surgery

Coronary artery spasm during the early postoperative period following cardiopulmonary bypass for coronary artery surgery can be an unrecognized cause of sudden, severe cardiopulmonary collapse. The literature regarding perioperative coronary artery spasm is reviewed, and methods of prevention, diagnosis, and treatment are suggested. Preoperative angina at rest appears to be an important identifying factor in patients who experience postoperative coronary spasm. Anatomically, the presence of a relatively normal, dominant right coronary may also indicate increased risk for early post-coronary bypass spasm. Acute hypotension is often the first sign of coronary artery spasm, and conventional treatment methods may only worsen the vasospastic reaction. Peripheral intravenous nitroglycerin infusion has often been unsuccessful treatment while intragraft or intracoronary nitroglycerin injection or administration of calcium channel-blocking drugs, or both, has proven to be effective in reversing the coronary artery spasm and ventricular dysfunction. Reluctance to use vasodilating agents must be overcome, even in the face of hypotension, when evidence of spasm is present.

Obstruction to Left Coronary Artery Blood Flow Secondary to Obliteration of the Coronary Ostium in Supravalvular Aortic Stenosis

Supravalvular aortic stenosis is characterized by obstruction of the left ventricular outflow tract distal to the aortic valve, and may result in diminished coronary artery blood flow. This report describes the cases of 2 patients in whom obstruction to left coronary artery flow was caused by obliteration of the coronary ostium itself. This mechanism differs from the more commonly recognized cause--valve leaflet adhesion to the obstructing ridge of aortic tissue. The coronary artery obstruction found in these 2 patients required direct enlargement of the left coronary ostium in both. This mechanism of impaired coronary artery flow deserves emphasis, as traditional methods of extended patch aortoplasty may fail to relieve the coronary ostial narrowing.

Management of spontaneous umbilical hernia disruption in the cirrhotic patient

Umbilical hernia is a common finding in cirrhotic patients with ascites. Spontaneous disruption of the hernia and attendant discharge of ascitic fluid is an unusual and rarely reported complication in these patients and is associated with an overall mortality rate of nearly 30%. During the 5-year period 1977–1982, nine patients with hepatic cirrhosis and ascites were treated for spontaneous rupture of an umbilical hernia. Ascites was attributed to alcoholic cirrhosis in all cases and was present for an average of 21 months prior to rupture. In two cases, failed peritoneovenous shunts resulted in reaccumulation of massive ascites. Initial management included sterile occlusive dressings, fluid repletion, and intravenous antibiotic administration. Hernia repair was performed an average of 4.2 days after rupture. General anesthesia was used in eight cases and local anesthesia in one case. In one instance, the hernia became incarcerated and required urgent repair. Postoperative complications, including wound infection and colonic dilatation, occurred separately in two patients (22%). One patient died of hepatic failure 28 days after operation, for an overall mortality rate of 11%. Surviving patients have been followed for an average of 8 months, and most have done well. Spontaneous rupture of umbilical hernia in patients with ascites occurs uncommonly. Operative management is indicated uniformly and can be conducted safely when the patients condition has stabilized. The prognosis is favorable for patients with good hepatic reserve.

Embolectomy for Acute Pulmonary Artery Occlusion Following Fontan Procedure

A 5-year-old child experienced acute hemodynamic decompensation and hypoxia four weeks following an uneventful Fontan procedure for univentricular heart. Cardiac catheterization revealed complete occlusion of the left pulmonary artery, and emergent pulmonary artery embolectomy was performed. The source of the embolus was the atrial septal patch. Because of the altered hemodynamics following the Fontan procedure, stasis of right atrial blood and thrombus formation may occur. Routine anticoagulation immediately following operation is recommended. Prompt diagnosis and treatment with embolectomy may be lifesaving.

Achalasia in children: Treatment by anterior esophageal myotomy (Modified heller operation)

Although rare in children, achalasia can be the cause of debilitating symptoms and growth retardation. During a 4-year period, six patients (mean age 9.9 years) underwent a modified Heller operation (anterior esophageal myotomy) without complication. A concomitant modified Belsey fundoplication was performed in three patients who were judged at the time of operation to be at high risk for postoperative gastroesophageal reflux. Preoperative symptoms of dysphagia, postprandial vomiting, retrosternal pain, and pulmonary complications were eliminated in all patients. Follow-up interviews seven to 48 months (mean 23 months) following operation revealed normal diet and normal growth in all six children, with no recurrence of preoperative symptoms or evidence of gastroesophageal reflux. Technical details which we believe contribute to success in the operative management of pediatric achalasia include the transthoracic approach and the selective performance of complementary anti-reflux procedures.

Early dilation in the treatment of esophageal disruption

During the past four years, 11 patients with disruption of esophageal continuity have received dilation therapy prior to the healing of the fistula. In 7 patients undergoing transhiatal esophagectomy with a cervical esophagogastric anastomosis, anastomotic leaks within 2 to 13 days (average, 8 days) after operation were treated by drainage, bedside esophageal dilations to at least a 46F bougie, and supplemental jejunostomy tube feedings. Bougienage was performed within 1 to 12 days (average, 6 days) of the diagnosis of a leak, and oral intake was not discontinued for more than 72 hours average. Fistula drainage stopped within 1 to 12 days (average, 6 days) of dilation in all patients. Four patients referred with chronic intrathoracic esophageal disruptions (2, middle third and 2, distal third) following resection of diverticula (2), esophageal dilation (1), and trauma from Harrington rods (1) were also treated successfully by drainage, esophageal dilation, or both. Periesophageal inflammation associated with an esophageal leak, esophageal spasm due to local irritation, or relative anastomotic narrowing may all contribute to obstruction distal to an esophageal disruption and adversely affect spontaneous closure. Dilation of the leaking esophagus is not dangerous if performed carefully and selectively, and in fact may promote healing of the injury.

Coronary Vasodilator Reserve in Young Dogs with Moderate Right Ventricular Hypertrophy

The effects of experimental right ventricular (RV) pressure overload and RV hypertrophy on coronary vasodilator reserve in young animals is not well established. Therefore, we measured coronary vasodilator reserve in the right ventricle of dogs from 7 to 12 months old with moderate RV hypertrophy due to pulmonary artery banding performed 3 to 7 days after birth. In the 5 dogs with pulmonary artery banding, substantial RV hypertension developed (RV pressure at rest, 73 +/- 11 mm Hg) as did RV hypertrophy (ratio of RV free wall/left ventricular free wall weight, 1.86 +/- 0.41 gm/kg). The reactive hyperemic response following brief coronary occlusions was used as an index of coronary vasodilator reserve. The ratios of peak reactive hyperemic response to resting flow, however, were not significantly different in the 5 banded dogs compared with 7 control animals (3.6 +/- 1.0 versus 2.6 +/- 0.6); this implies that the extent of vasodilator reserve was similar with or without moderate RV hypertrophy. In addition, myocardial blood flow, as determined using radioactive microspheres, was not significantly different at rest: 0.57 +/- 0.09 ml/min per gram in the banded dogs versus 0.48 +/- 0.12 ml/min per gram in the controls. Uniform transmural distribution of blood flow was maintained during infusion of isoproterenol, which was used to increase myocardial oxygen requirements in both groups. Minimum coronary vascular resistance was significantly lower in the banded than the control dogs (1.5 +/- 0.6 versus 6.2 +/- 2.3; p less than 0.01). This difference suggests that the cross-sectional area of the right coronary vascular bed increased with the development of RV hypertrophy.

The Influence of Tumor Microfoci on Recurrence and Survival Following Pulmonary Resection of Metastatic Osteogenic Sarcoma

Factors that influence recurrence and survival following thoracotomy for metastatic osteogenic sarcoma are not well defined. We examined the clinical and pathological material from 51 patients who had no metastases at the time of operative treatment of osteogenic sarcoma at the University of Michigan from 1962 to 1982. Ages ranged from 2 to 30 years (mean, 15 years). Metastases developed in 37 patients (72.5%) at a mean of 8 months after initial operation. Thirteen patients were treated with chemotherapy only; 12 of them died after a mean survival of 7 months. Twenty-four patients were treated with chemotherapy and 45 thoracotomies (mean, 1.9 per patient; range, 1 to 5) during which 120 wedge resections or lobectomies were performed. Follow-up is available on 22 of these 24 patients, 11 (50%) of whom are alive (9, tumor free) at a mean of 51 months after thoracotomy. Eleven patients died after a mean survival of 27 months (p less than or equal to 0.001 compared with the group having chemotherapy only). Microfoci of tumor (tumor cells separate from the gross tumor nodule) were found in resection specimens in 12 patients at the first thoracotomy; in 11 of these 12 patients, new metastases subsequently developed resulting in 10 reoperations. Twelve patients had no microfoci at the first operation; new metastases developed in 5; 3 underwent reoperation. Overall, microfoci were found at 29 operations; in patients with this finding, new metastases developed twenty-seven times (93%).(ABSTRACT TRUNCATED AT 250 WORDS)