Surgical management of diffuse subaortic stenosis: an integrated approach

Classic Konno-Rastan Procedure: Indications and Results in the Current Era

Diffuse or unresectable subaortic stenosis is difficult to treat and needs aggressive resection to effectively relieve the obstruction. Anterior aortoventriculoplasty, known as the Konno-Rastan procedure, has been shown to effectively tackle the problems encountered in diffuse subaortic stenosis. A retrospective study was carried out on patients who had undergone a Konno-Rastan procedure at our institution from March 1997 to November 2003. There were 26 patients (16 males and 10 females). The mean age at operation was 12.8 ± 7 years. The mean follow-up period was 30.4 ± 14.5 months. Only mechanical valves were used in this group of patients. The overall 30-day mortality was 11.5% (3 patients). The mean preoperative peak systolic gradient decreased significantly from 91.3 ± 39.3 to 28.1 ± 17.7 mm Hg. Four patients developed permanent complete heart block and 2 had a residual ventricular septal defect in late follow-up. The classic Konno-Rastan procedure using a mechanical valve can be performed with acceptable morbidity and mortality in this difficult group of patients.

Long-term Outcome and Risk of Heart Block After Surgical Treatment of Subaortic Stenosis

Although mortality following repair of subaortic obstruction is low, aggressive resection may increase morbidity. We sought to evaluate outcomes and risk of atrioventricular heart block (AVB) after subaortic resection in the current era. Simple obstruction was defined as a discrete subaortic membrane and complex as multilevel or diffuse narrowing. Limited resection included membranectomy and limited myomectomy. Aggressive resection included Konno, modified Konno, and Ross. Specified variables were obtained from a chart review. The 185 consecutive patients (1991-2008) ranged in age from 1 day to 21.8 years (5.1 ± 5.1 years) with 2 early and 4 late deaths. Actuarial survival was 97%, 95%, and 95% at 1, 5, and 10 years, respectively. Reoperations were required in 29 of 185 patients (15.7%); 2 required a third operation (1%). Freedom from reoperation in all patients was 97%, 83%, and 73% at 1, 5, and 10 years, respectively. Accessory mitral valve tissue ( P < .001) and age <3 months ( P = .004) predicted the need for reoperation. Transient or permanent high-degree AVB was documented in 33 of 185 patients (17.8%). Complex anatomy ( P = .01) and aggressive resection ( P < .001) increased the risk of acquiring AVB. The AVB was permanent in 21 of 185 (11.4%) patients, and pacemaker implantation was undertaken in 20 of 185 (10.8%) patients. Complex anatomy ( P = .04) and modified Konno procedure ( P = .03) increased the risk of acquiring a pacemaker. Aggressive resection lowered the frequency of recurrence but increased the risk of AVB. When aggressive resection is considered for long-term relief of subaortic obstruction, the risk of reobstruction must be balanced with the risk of AVB and the need for pacemaker implantation.

Surgical treatment of subaortic obstruction in adolescent and adults: long-term follow-up

Subaortic stenosis (SAS) is a wide spectrum of anatomical derangements ranging from a discrete fibrous membrane to tortuous fibrous tunnel with or without aortic annulus hypoplasia. We have reviewed 88 patients undergoing surgery for SAS over a 15-year period. There were 47 male and 41 female patients with a mean age of 19.8 +/- 10.6 years (range 11 to 39). Fifty-eight patients had discrete subaortic membrane, and 30 patients had diffuse tunnel subvalvular stenosis. The mean systolic pressure gradients were found to be 86.5 +/- 31.4 mmHg (range 48 to 145 mmHg). Ten patients had mild and 13 patients had moderate-to-severe aortic insufficiency (AI) preoperatively. Nine patients had bicuspid aortic valve. Forty patients (45.4%) had associated cardiac lesions. Isolated membranectomy was performed in six patients. Membranectomy associated with septal myectomy was done in 52 patients. Fifteen patients of them associated hypoplasia of the aortic orifice necessitated aortic valve replacement (AVR) using the Konno-Rastan procedure. Fifteen patients with tunnel SAS and normal aortic valves underwent a combined approach for valve sparing, a modified Konno procedure with patch septoplasty. Also eight patients required AVR because of the severity of AI and five patients aortic reconstruction procedures. Aortic commissurotomy was performed to relief of stenosis in four patients. There were three early deaths (3.4%) and one late death (1.1%) all after the Konno-Rastan procedure. Eight patients (9.1%) had permanent conduction abnormalities. Postoperative left ventricle-aorta gradient was significantly decreased at early postoperative period (p < 0.001) and ranged from 10 to 25 mmHg (mean 14.1 +/- 4.3). Fourteen patients (16.5%) were reoperated for recurrent obstruction or progression of AI. The mean reoperation interval was 4.4 +/- 1.7 years (range 2 to 8 years). Five-year reoperation-free survival was 88.0 +/- 3.6% and 12.5-year reoperation-free survival was 75.5 +/- 7.0%. Our results of aggressive surgical approach of subvalvular aortic stenosis produces relief of obstruction and frees the valve leaflets, significantly reducing associated AI with long-term survival and long-term adequate relief of left ventricular outflow tract obstruction.

Outcome of septal myectomy in patients with hypertrophic obstructive cardiomyopathy

OBJECTIVES

To study the outcome of septal myectomy in patients with hypertrophic obstructive cardiomyopathy.

DESIGN

Septal myectomy in patients with hypertrophic cardiomyopathy with obstruction of the left ventricular outflow tract (HOCM) is symptomatically effective, and complication rates have been found to be low in large centres performing the procedure routinely. Representing a small centre we studied the outcome after septal myectomy in 11 consecutive patients, aged 44 +/- 21 (mean +/- SD) years with HOCM myectomized at our institution from 1991 to 1998. The patients were evaluated preoperatively using echocardiography and left-sided heart catheterization.

RESULTS

Eight patients were operated on after medical treatment had failed and three after sudden deterioration of cardiac function. A Morrow myectomy was performed in 10 patients and a modified Konno procedure in one. Significant reductions were observed in left ventricular outflow tract gradients (77 +/- 29 to 10 +/- 7 mmHg, p < 0.01; n = 11), the degree of mitral valve regurgitation (grades 0-3) (1.7 +/- 1.0 to 0.8 +/- 0.7, p < 0.01; n = 11), NYHA functional classification score (2.4 +/- 1.0 to 1.5 +/- 0.7, p < 0.01; n = 11) and all five patients with angina preoperatively had an improved CCS angina classification score. There were no operative or early postoperative (30 days) deaths. One patient operated on with the modified Konno procedure was reoperated for a septal patch suture leak. During follow-up (43 +/- 24 months, range 11-83), the linearized mortality rate was 3.6% per year. One patient died from a pancreas cancer, one probably from coronary artery disease and one suddenly of unknown cause.

CONCLUSION

We conclude that septal myectomy efficiently relieves symptoms in HOCM patients, possibly reflecting the direct as well as secondary effects of left ventricular outflow tract gradient reduction. The present results, obtained at a smaller centre for this procedure, should be considered when choosing from available therapeutic alternatives when medical therapy fails: dual chamber pacemaker implantation, percutaneous transluminal septal myocardial ablation or myectomy.

Ventricular morphology and coronary arterial anatomy in hearts with isometric atrial appendages

BACKGROUND

Knowledge of the precise anatomy can be advantageous when striving to improve surgical results in patients with visceral heterotaxy.

METHODS

We studied the ventricular mass, and its coronary arterial supply, in 125 specimens with isomeric right and 58 with isomeric left appendages.

RESULTS

The situation in which each atrium connected to its own ventricle was the most common arrangement in hearts with isomeric left appendages. The pattern with both atriums connecting to the same ventricle was more frequently seen in those with isomeric right appendages. Concordant ventriculoarterial connections were seen in only 4% of cases with isomeric right appendages, but were seen in 45% of those with isomeric left appendages. Abnormal patterns in branching of the coronary arteries were commonly associated with abnormal ventricular architecture. The morphologically right or left ventricular arteries were frequently lacking in those hearts with a dominant ventricle and a rudimentary and incomplete ventricle. A solitary coronary artery was seen in 13%.

CONCLUSIONS

Recognition of these abnormalities is of clinical importance if optimal surgical strategies are to be established for patients with visceral heterotaxy.

Perioperative conduction and rhythm disturbances after the Ross procedure in young patients

BACKGROUND

The Ross procedure is performed for a variety of left ventricular outflow tract diseases in children. The preoperative hemodynamic burden of pressure or volume overload and associated ventricular hypertrophy can predispose to ventricular arrhythmias. Additional procedures performed with the Ross procedure (eg, Konno) may damage the conduction system.

METHODS

Between January 1995 and February 1997, the Ross procedure was performed in 42 patients, 31 (74%) of whom had 71 prior interventions. Concomitant procedures (n = 42 in 23 patients) included 17 annular-enlarging procedures. Screening was performed for perioperative conduction and rhythm abnormalities.

RESULTS

There was one postoperative death. Perioperative ventricular tachycardia occurred in 12 patients (29%), with 2 receiving antiarrhythmic medication for ventricular tachycardia at discharge. Transient complete heart block occurred in 3 patients, all of whom had concomitant procedures performed in the subaortic area; all patients were discharged in sinus rhythm and no patient received a permanent pacemaker.

CONCLUSIONS

The Ross procedure can be performed successfully in children with complex cardiac disease with low mortality and perioperative morbidity. The incidence of perioperative ventricular tachycardia is high (29%), suggesting the need for vigilant perioperative monitoring and long-term surveillance.

Transaortic resection of the subaortic membrane. Treatment for subvalvular aortic stenosis

In an attempt to better understand congenital subaortic stenosis, we reviewed 19 consecutive pediatric patients undergoing surgery for this problem between 1973 and 1984. Preoperative cardiac catheterization demonstrated subvalvular stenosis in all patients and associated anomalies in 11 patients. All patients underwent transaortic resection of the subaortic membrane. Five patients underwent concurrent additional cardiac procedures. An 8-month-old infant with multiple cardiac anomalies was the only operative mortality. Follow-up extended to 16 years, with a mean of 6.9 years. In five symptomatic patients, cardiac catheterization revealed a mean systolic pressure gradient of 33.0 +/- 31.94 mm Hg 24.7 months (mean) after surgery. Two of these patients (11.1 percent of survivors) required reoperation. Twelve of the remaining 13 asymptomatic patients underwent echocardiographic follow-up, and 4 were found to have recurrent stenosis with 1 requiring surgery (5.6 percent of survivors). Our experience shows that transaortic resection of the subaortic membrane is an acceptable treatment for subvalvular aortic stenosis, but is associated with a high incidence of recurrence requiring reoperation (3 of 18 or 16.7 percent). Consequently, it is reasonable to consider the role of alternative therapies which may help prevent recurrence in selected cases.

Ventricular septal defect creation for relief of tunnel subvalvular aortic stenosis

In infants, the management of severe tunnel subvalvular aortic stenosis associated with hypoplastic aortic annulus remains a major surgical challenge. We report a case of such lesion treated by rerouting the systemic blood flow through a created subpulmonary ventricular septal defect toward the right ventricular outflow tract and the pulmonary valve. This technique provided complete relief of the left ventricular outflow tract obstruction without the implantation of a systemic prosthetic valve.

Konno procedure for congenital aortic stenosis with a single coronary artery from the left coronary sinus

A right coronary artery originating from the left coronary sinus and traversing anteriorly is thought to be one of the contraindications for a Konno aortoventriculoplasty in congenital aortic stenosis because this procedure necessitates incision of the right ventricular outflow tract. The case of a 5-year-old girl with congenital aortic stenosis associated with a single coronary artery, successfully treated surgically by the Konno procedure and right coronary artery reimplantation, is reported. Preoperatively there was a pressure gradient between the left ventricle and the ascending aorta of 109 mmHg, which disappeared postoperatively. A postoperative angiography showed a patent right coronary artery.