Gulshan K. Sethi

Starting aspirin therapy after operation. Effects on early graft patency. Department of Veterans Affairs Cooperative Study Group.

BackgroundAlthough aspirin therapy started before operation improves vein graft patency after coronary artery bypass grafting, it also causes bleeding. The objective of this prospective, centrally directed, randomized, double-blind, placebo-controlled trial was to compare the effects of aspirin therapy started before operation with aspirin started 6 hours after operation on early (7–10-day) graft patency. Methods and ResultsPatients were randomized to receive either aspirin 325 mg or placebo the night before surgery; after operation, all patients received aspirin 325 mg daily, with the first dose administered through the nasogastric tube 6 hours after operation. Angiography was performed in 72% of the analyzed patients an average of 8 days after operation, and the primary end point was saphenous vein graft patency in 351 patients. Internal mammary artery graft patency was also assessed in 246 patients because many individuals received both internal mammary artery and vein grafts. In the patients given preoperative aspirin, the vein graft occlusion rate was 7.4 ± 1.3% compared with 7.8 ± 1.5% in those who received preoperative placebo (p =0.871). In the subgroup of patients receiving Y grafts, 0.0% of the grafts were occluded in the preoperative aspirin group compared with 7.0 ± 3.6% in the preoperative placebo group (p =0.066). The internal mammary artery occlusion rate was 0.0% (0 of 131) in the aspirin group compared with 2.4 ± 1.4% (three of 125) in the placebo group (p =0.081). Patients in the aspirin group received more transfusions than those in the placebo group (median, 900 versus 725 ml,p=0.006). The reoperation rate for bleeding in the aspirin group was 6.3% compared with 2.4% in the placebo group (p =0.036). Median chest tube drainage within the first 6 hours after operation was 500 ml in the aspirin group compared with 448 ml in the placebo group (p =0.011). Conclisions. Thus, preoperative aspirin is associated with increased bleeding complications and offers no additional benefit in early vein graft patency compared with starting aspirin therapy 6 hours after operation. There was a trend, although not significant, toward improved early patency for Y grafts and internal mammary artery grafts with preoperative aspirin.

Long-term graft patency (3 years) after coronary artery surgery. Effects of aspirin: results of a VA Cooperative study.

BACKGROUNDnThe long-term success of coronary bypass surgery is dependent on graft patency after surgery. This trial was designed to determine if aspirin improved saphenous vein graft or internal mammary artery (IMA) graft patency between 1 and 3 years after coronary artery bypass grafting (CABG).nnnMETHODS AND RESULTSnAfter receiving aspirin 325 mg/d for 1 year after CABG and undergoing a 1-year postoperative cardiac catheterization, patients were randomized to receive either aspirin (325 mg) or placebo for 2 additional years. Angiography was performed 3 years after surgery to determine the primary end point-saphenous vein graft patency in 288 patients and IMA graft patency in 167 patients. At 3 years after CABG, the saphenous vein graft occlusion rate was 17.0% (62 of 365) for patients treated with aspirin compared with 19.7% (74 of 376) for those who received placebo (P = .404). For saphenous vein grafts that were patent at 1 year, the occlusion rate at 3 years was 4.8% (15 of 313) for patients treated with aspirin compared with 4.2% (13 of 310) for patients who received placebo (P = .757). At 3 years, the IMA graft occlusion rate was 10.3% (8 of 78) for patients treated with aspirin compared with 7.9% (7 of 89) for patients who received placebo (P = .594). For IMA grafts that were patent at 1 year, the occlusion rate was 4.3% (3 of 70) for patients treated with aspirin compared with 2.5% (2 of 81) for patients who received placebo (P = .541).nnnCONCLUSIONSnThese data suggest that aspirin treatment does not improve saphenous vein graft or IMA graft patency between 1 and 3 years after CABG.

Opportunistic Endocarditis Following Open-Heart Surgery

The incidence of endocarditis following open-heart operations is declining, but the relative incidence of endocarditis by the opportunistic organisms, both bacterial and fungal, has increased. These opportunists require careful identification and sensitivity testing so that appropriate therapy can be planned. In cases of candida endocarditis, a positive precipitin test and elevated candida antibody titer may provide an earlier means of diagnosis than blood cultures. These patients should be treated promptly with adequate dosages of specific antimicrobial or antifungal agents. Reoperation should be considered early if there is evidence of valve dehiscence or embolic phenomena or if drug therapy fails to control the infection.

Six month postoperative hemodynamics of the Hancock heterograft and the Björk-Shiley prosthesis: Results of a Veterans Administration Cooperative prospective randomized trial

In a Veterans Administration Cooperative Study involving 13 medical centers, 575 patients undergoing single valve replacement were prospectively randomized to receive either the standard Björk-Shiley prosthesis or the Hancock porcine heterograft (with a modified orifice for sizes 23 and smaller). The hemodynamic data in the 268 patients who underwent cardiac catheterization an average of 6 months (range 3 to 12) postoperatively are reported. Statistical analyses were performed on valve sizes 23, 25 and 27 in the aortic position, and 29, 31 and 33 in the mitral position. A wide variation was observed in mean pressure gradient and calculated orifice area in both valve types within all sizes in both the aortic and the mitral positions. In the aortic position, the Björk-Shiley prosthesis tended to have a lower pressure gradient and larger calculated orifice area than the Hancock heterograft, but the differences in gradient between the two valve types were significant only in the larger-sized valves. The difference in calculated area between the two valve types was not significant within each valve size. In the mitral position, there were no differences in gradient and calculated orifice area between the two types of prostheses. The postoperative cardiac index, regurgitant volume, pulmonary artery systolic and mean pressures, left ventricular end-diastolic pressure, left ventricular ejection fraction and left ventricular end-diastolic volume index did not differ in patients receiving the Björk-Shiley prosthesis from values in patients receiving the Hancock heterograft. Hence, the overall hemodynamic performance of both types of valves is remarkably similar. The choice between these two prostheses should, therefore, be governed not by the hemodynamic performance, but by other factors such as valve durability, risk of anticoagulation and incidence of valve-related complications.

Innominate venous thrombosis: A rare complication of transvenous pacemaker electrodes

Abstract Thrombosis and occlusion of innominate veins or superior vena cava are extremely rare, but may be a major complication of transvenous pacing electrodes. These patients have the usual signs and symptoms of superior vena caval syndrome and should be managed with anticoagulation therapy.

Tension pneumoperitoneum and gastric rupture following cardiopulmonary resuscitation.

Inadvertent esophageal intubation during cardiopulmonary resuscitation following aortocoronary bypass grafting resulted in gastric rupture and tension pneumoperitoneum in a 65-year-old patient. Rapid hemodynamic deterioration necessitated emergency laparotomy with successful repair of the gastric rupture. The patients recovery was uneventful, and he was doing well at six months follow up. Awareness of this unusual complication may lead to early recognition and successful treatment.

Esophagopleural Fistula Following Pulmonary Resection

The development of esophagopleural fistula following pulmonary resection is an uncommon but serious complication. The fistula may appear either soon after operation, due to direct trauma to the esophagus or to its blood supply during extensive dissection, or later, in association with the development of a bronchopleural fistula and empyema following the pulmonary resection. Treatment of these fistulas is usually complicated, and the recovery period is prolonged. Control of infection, hyperalimentation, obliteration of the empyema space, and closure of the fistula with a muscle or pleural flap are recommended methods of management. The pathogenesis, treatment, results, and prevention of this complication are discussed.

False aneurysm of the abdominal aorta due to blunt trauma.

Nonpenetrating trauma to the abdominal aorta is uncommon and the development of a traumatic abdominal aortic aneurysm is even more rare. The victims of blunt trauma to the abdomen should be examined for diminution or absence of femoral pulses, especially if numbness, diminished sensations, or motor weakness appear following trauma. If pulse abnormalities are present, aortography should be performed promptly to exclude aortic disruption or dissection. Immediate surgery should be performed once the diagnosis of aortic disruption is made. To our knowledge, this is the second reported case of successful surgical treatment of a false aneurysm of the abdominal aorta following nonpenetrating trauma.

Systemic Emboli due to Cloth Wear in a Starr-Edwards Model 2320 Aortic Prosthesis

Abstract The evolution of the different cloth coverings of Starr-Edwards prostheses is reviewed along with previously reported cases of wear of the cloth coverings. The first case of wear in the Model 2320 valve, which is covered with a combination of polypropylene over Teflon, is reported. Questions related to the problem are discussed.

The sutureless aortic valve prosthesis: experience with and technical considerations for replacement of the early model.

Reoperation was performed in seven (16%) of 43 patients with early models of Magovern sutureless aortic valve prostheses, because of thromboembolism and ball variance. All patients survived reoperation with no major complications. Removal of the sutureless prosthesis was not difficult when an insertion tool of proper size was used. A scarred annulus remained which was favorable for the suturing of a new prosthesis. The incidence of disabling thromboembolism (42%) and poppet failure (21%) is high with these early models. When these complications occur, replacement of the prosthesis is recommended to prevent death or recurrent embolic episodes.