The aortic homograft: evolution of indications, techniques, and results in 107 patients.

BACKGROUND: Homograft aortic valve replacement has been performed in 107 patients during the past 7 years. Two primary methods of implantation were used (intraaortic and root replacement). Results of both methods are presented. METHODS: Intraaortic implantation (subcoronary or cylinder technique) was performed in 36 patients (mean age, 54 years) for aortic stenosis or regurgitation (31 patients) and endocarditis (5 patients). Aortic root replacement was performed in 71 patients (mean age, 62 years). The majority (58 patients) had complex root pathologies such as ascending aneurysm, dissection, or prosthetic endocarditis with annular destruction. Early results were assessed with intraoperative or predischarge echocardiography; annual echocardiograms provided long-term follow-up. Left ventricular mass was calculated in patients with long-standing pathology for whom preoperative and postoperative data were available. RESULTS: Early valvular insufficiency was documented in 16 of the 36 intraaortic implants (44%); 9 of these have had progression of the insufficiency. Of the 20 patients who had trivial or no early insufficiency, significant insufficiency has developed in 7 and mild insufficiency has developed in 5. Calculation of left ventricular mass revealed a mean reduction of 11% at 1 year. There has been no mortality, endocarditis, or homograft-related reoperation in the intraaortic group with a mean follow-up of 50 months. The root replacement group had a hospital mortality of 17%. The cardiac pathology was limited to the aortic valve in 12 patients; mortality in this subset was zero. There has been no significant early or late postoperative valvular insufficiency in the 59 surviving patients. More rapid left ventricular mass reduction was seen in this group with a 26% mean reduction within 1 year. A mean follow-up of 32 months in the root replacement group has seen no homograft-related reoperations. CONCLUSIONS: Although the lack of early mortality in the intraaortic group makes this technique appealing, the high incidence of early insufficiency with the realistic expectation of progression has led to our abandonment of the intraaortic technique. Homograft aortic root replacement confers a higher mortality based on the severity of aortic pathology, but offers excellent long-term hemodynamics in any patient. We have expanded our indication for homograft root replacement to include patients with isolated valvular disease rather than reserving it for those patients with extensive root pathology.

Early experience with homograft aortic root replacement for complex aortic pathology.

BACKGROUND: Complex aortic valve and root pathology presents a serious operative challenge. METHODS: During the last 45 months 21 cryopreserved homograft root replacements have been performed in 19 patients. The ages of the patients ranged from 28 to 77 years; there were 15 men and four women. Six patients had endocarditis, four prosthetic and two native valve endocarditis. One patient underwent homograft aortic root replacement twice; one underwent concomitant homograft right ventricular outflow tract reconstruction for pulmonic endocarditis. Causes of aortic pathology in the other 13 patients included ascending aortic aneurysm with valvular regurgitation in seven, Marfan syndrome in two, and four aortic dissections with aortic regurgitation. Ten of the nineteen patients were undergoing reoperative procedures. RESULTS: There were three hospital deaths and one death at home of unknown cause. Two of the three patients who died in hospital had undergone redo cardiac procedures. Dramatic functional class improvement was seen in all survivors. CONCLUSIONS: Follow-up from 2 to 45 months in the fifteen survivors revealed no clinical or significant echocardiographic evidence of valvular regurgitation or recurrent infection. We believe homograft root replacement provides an excellent method of reconstruction with several advantages unique to human valved conduits, including ease of handling, lack of synthetic nidus for recurrent infection, and absence of thrombogenic materials. Homografts should be considered the approach of choice in complex valvular and root infectious processes.

Descending necrotizing mediastinitis: transcervical drainage is not enough.

One of the most lethal forms of mediastinitis is descending necrotizing mediastinitis, in which infection arising from the oropharynx spreads to the mediastinum. Two recently treated patients are reported, and the English-language literature on this disease is reviewed from 1960 to the present. Despite the development of computed tomographic scanning to aid in the early diagnosis of mediastinitis, the mortality for descending necrotizing mediastinitis has not changed over the past 30 years, in large part because of continued dependence on transcervical mediastinal drainage. Although transcervical drainage is usually effective in the treatment of acute mediastinitis due to a cervical esophageal perforation, this approach in the patient with descending necrotizing mediastinitis fails to provide adequate drainage and predisposes to sepsis and a poor outcome. In addition to cervical drainage, aggressive, early mediastinal exploration--debridement and drainage through a subxiphoid incision or thoracotomy--is advocated to salvage the patient with descending necrotizing mediastinitis.

The efficacy and timing of operative intervention for spontaneous pneumothorax.

To reassess the role and timing of operative intervention for spontaneous pneumothorax, 119 patients were retrospectively reviewed to compare recurrences, complications, and hospital stay between a nonoperative group (Group 1) and an operative group (Group 2). Total hospital days were greater in Group 2, but excluding the length of preoperative stay, the number of hospital days were similar in both groups. Group 1 patients more than 40 years old had a longer postoperative hospitalization, but not a higher rate of complication. Overall, morbidity was not different between the two groups, and there were no immediate or perioperative deaths in either group. There were no recurrences in Group 2. At least 11 of the 49 patients in Group 1 had a recurrence (p = .012). Considering the excellent results achieved with operative pleurodesis and the total hospital days accrued with nonoperative therapy, operative pleurodesis should be considered if an active leak persists more than three days after the initial episode of spontaneous pneumothorax or at the time of the first recurrence in the hospitalized patient.

Evacuation of calcific valvular debris using a standard Ellik evacuator.

A simple but effective technique is described for removing calcific and other debris following aortic and mitral valve replacement. This technique uses an Ellik evacuator , which is readily available in most operating rooms. An 11-year experience is presented, documenting the efficacy of this method in several hospitals.

Acute reaction to protamine. Its importance to surgeons.

Three open heart surgery patients developed noncardiogenic pulmonary edema after administration of protamine following cardiopulmonary bypass. A catastrophic series of events are characteristic of this reaction: 1) sudden onset; 2) severe bronchoconstriction with early extreme difficulty in ventilation; 3) hyperinflation of the lungs; 4) pulmonary hypertension with normal pulmonary wedge or left atrial pressures; 5) progression to fulminant noncardiogenic pulmonary edema; 6) significant mortality; and 7) ventilatory perfusion abnormalities in survivors. Review of the literature reveals three types of reactions to protamine injection of varying severity: 1) brief hypotension; 2) anaphylactoid generalized reaction; and 3) high protein noncardiogenic pulmonary edema with cardiopulmonary collapse. The severity of the reaction had no relation to the dose of protamine. Previous protamine exposure was documented in 14 of 35 cases. Awareness of this reaction is essential for prompt treatment if fulminant pulmonary edema occurs. Administration of epinephrine, steroids, vasopressors, and potassium replacement may be required. Needless use of protamine sulfate should be discouraged.

Serum and urinary amylase levels following pulsatile and continuous cardiopulmonary bypass.

The incidence of elevated serum and urine amylase values was examined in a prospective clinical study of patients subjected to either continuous or pulsatile extracorporeal perfusion. Mean postoperative values for urine and serum amylase were higher in the continuous group, and the incidence of abnormal values was also greater in the continuous group (70 percent versus 32 percent, p less than 0.01). Clinical pancreatitis was absent in both groups. This study documents a high incidence of elevated amylase values following bypass with either modality and provides evidence for possible improved visceral circulation with pulsatile extracorporeal bypass during routine cardiac operations.

The treatment of acute traumatic rupture of the aorta: a 10-year experience.

Forty-three patients with aortic rupture secondardy to blunt trauma have been treated at the University of Micigan within the past 10 years with an overall salvage rate of 70%. The diagnosis should be suspected in anyone who has sustained a high speed decelerating injury, if the chest roentgenogram shows media-stinal widening, whether or not there is hypertension of the upper extremities; systolic murmur, or external evidence of chest injury. Aortography should be employed to confirm the diagnosis and to determine the site or sites of rupture. Repair of the lesion should be undertaken as soon as possible and takes priority in most instances over associated injuries. Repair in almost all cases can be accomplished safely and quickly using a bypass shunt without the aid of extracorporeal circulation.

A different approach for the total correction of tricuspid atresia.

A new surgical procedure has been used successfully to correct tricuspid atresia in a 9-year-old girl. An external conduit containing a porcine aortic valve was positioned to lead from the right atrium to the underdeveloped right ventricle. The right ventricle was reconstructed with a large Dacron patch, thus providing a large cavity for the small hypoplastic right ventricle. The atrial and ventricular septal defects were closed. The patient made a satisfactory recovery and is doing well four months after the operation.