Postoperative Left Ventricular Outflow Tract Research Articles

Individualised surgical treatment strategy for subaortic stenosis.

The clinical data of patients with subaortic stenosis who underwent surgical treatment in our centre in the past 12 years were reviewed. The short-term and long-term clinical outcomes were analyzed, and the long-term outcomes of different surgical methods for subaortic stenosis were compared to determine the optimal surgical treatment strategy for subaortic stenosis. From December 2010 to December 2022, 90 patients undergoing surgical treatment for subaortic stenosis in our hospital were enrolled. There were 55 males and 35 females with a median age of 72 (46,132) months and an average surgical weight of (21.35 ± 15.84) kg. According to the operation method, 90 patients were divided into group A (50 patients with simple subaortic membrane resection) and group B (40 patients with subaortic membrane and muscle resection or modified Konno procedure). There were three early deaths (3.33%). One late death occurred in group B. There was no significant difference in long-term survival rate between the two groups (p = 0.904). The preoperative left ventricular outflow tract pressure gradient in group B was (91.56 ± 36.98) mm Hg, which was higher than that in group A(51.13 ± 36.04)mm Hg(p < 0.001). There was no significant difference in immediate postoperative left ventricular outflow tract pressure gradient between group B [(5.44 ± 8.43) mm Hg] and group A [(7.82 ± 13.44) mm Hg] (p = 0.343). In the long-term follow-up, left ventricular outflow tract pressure gradient in group B was (5.86 ± 9.53) mm Hg, which was not statistically significant compared with group A (8.83 ± 14.52) mm Hg (p = 0.294). Eleven patients with moderate or greater aortic regurgitation (group A/group B: 3/8) underwent simultaneous aortic valvuloplasty. In group B, moderate or greater aortic regurgitation was significantly improved immediately after operation (p = 0.013) and was not significantly aggravated in long-term follow-up (p = 0.083), and there was no significant improvement in group A after operation and long-term follow-up. According to the different anatomical lesions of left ventricular outflow tract, the individualised surgical treatment strategy for patients with subaortic stenosis can achieve good long-term outcomes. The long-term survival rate and freedom from reoperation due to late left ventricular outflow tract obstruction after simple subaortic membrane resection and extended left ventricular outflow tract resection are comparable. For patients with moderate or greater aortic regurgitation before extended left ventricular outflow tract resection, simultaneous aortic valvuloplasty is beneficial to improve postoperative aortic valve function.

The role of abnormal subaortic morphometry as a substrate for left ventricular outflow tract obstruction following atrioventricular septal defect repair.

Although left ventricular outflow tract (LVOT) obstruction is a recognized risk after atrioventricular (AV) septal defect (AVSD) repair, quantitative assessments to define the substrate of the obstruction are lacking. Morphometric analyses were based on measurements from early 2-dimensional echocardiographic scans (within 3 months postoperatively) for 117 patients (82 CAVVO = common AV valve; 35 SAVVO = separate AV valve orifices), which were compared to 50 age/weight matched controls (atrial septal defect/ventricular septal defect). Late echocardiographic analyses were performed in 57 patients with AVSD (follow-up range, 1.2-10.7 years). Adequate z scores (above -2.5) were observed in 109 (93%) patients with AVSD at the aortic annulus and in 89 (76%) with AVSD in the subaortic area. Compared to the control group, patients with AVSD had lower median z scores at the aortic annulus (-0.64 vs 0.60; P < 0.001) and the subaortic areas (-1.48 vs 0.59; P < 0.001), disproportionate subaortic/aortic annulus ratio <1.00 (67% vs 22%; P < 0.001), narrower annuloaortic-septal angle (94.0 vs 104.0; P < 0.001) and annuloaortic left AV valve angle (78.0 vs 90.0; P < 0.001). Compared to patients with CAVVO, those with SAVVO had narrower annuloaortic-septal angles (P = 0.022) that persisted at late analysis, with lower subaortic/aortic annular ratios (P = 0.039). In patients with CAVVO, lower early postoperative subaortic z scores were found following modified single-patch repairs (median -2.12 vs -1.02 in two-patch repairs; P = 0.004). A total of 6/117 (5%) patients (4 CAVVO, 5% and 2 SAVVO, 6%) required reoperations for LVOT obstruction (mean 6.9 years postoperatively), with no difference in morphology or types of operations. Despite having adequate z scores, patients with AVSD demonstrated abnormal LVOT morphometrics early postoperatively. Besides intrinsic morphology, repair techniques may have an impact on postoperative LVOT morphometrics and requires further evaluation.

Influence of operator volume on early outcomes of septal myectomy for isolated hypertrophic obstructive cardiomyopathy.

BackgroundGuidelines on the diagnosis and management of hypertrophic cardiomyopathy (HCM) recommend that septal myectomy be performed by experienced operators. However, the impact of operator volume on surgical treatment outcomes for isolated HCM has been poorly investigated.MethodsFrom 2002 to 2014, 435 consecutive patients with isolated HCM undergoing myectomy at the Fuwai Hospital were retrospectively enrolled. All 29 surgeons were divided into beginner surgeons (operator volume ≤20) and experienced surgeons (operator volume >20) according to the guidelines for the diagnosis and treatment of HCM. Propensity score matching of patients in the two groups was performed.ResultsBaseline differences included advanced New York Heart Association classification and older age in the experienced surgeon group. After matching, in the beginner surgeon group (107 cases), residual obstruction (18.7% vs. 0.9%, P<0.001) was more common, and the postoperative left ventricular outflow tract pressure gradient (20.7±15.1 vs. 14.3±7.4 mmHg, P<0.001) was higher than that of the experienced surgeon group. In the experienced surgeon group (107 cases), the incidence of mitral valve replacement (1.9% vs. 11.2%, P<0.001) and permanent pacemaker implantation (1.9% vs. 3.7%, P<0.001) was significantly lower than that in the beginner surgeon group. However, there was no difference in procedural mortality (1.9% vs. 1.9%) between the two groups.ConclusionsOperator volume is an important factor in achieving better obstruction obliteration after septal myectomy in patients with isolated HCM.

Is anterior mitral valve leaflet length important in outcome of septal myectomy for obstructive hypertrophic cardiomyopathy?

ObjectivesElongation of mitral valve leaflets is a phenotypic feature of hypertrophic cardiomyopathy, and some surgeons advocate plication of the anterior leaflet at the time of septal myectomy. The present study investigates mitral valve leaflet length and outcomes of patients undergoing septal myectomy for obstructive hypertrophic cardiomyopathy. MethodsWe reviewed the records and echocardiograms of 564 patients who underwent transaortic septal myectomy for obstructive hypertrophic cardiomyopathy between February 2015 and April 2018. Extended septal myectomy without plication of the anterior leaflet was the standard procedure. From intraoperative prebypass transesophageal echocardiograms, we measured anterior and posterior mitral valve leaflets and their coaptation length. For comparison, we performed these mitral valve leaflet measurements in 90 patients who underwent isolated coronary artery bypass grafting and 92 patients undergoing aortic valve replacement in the same period. Among patients with hypertrophic cardiomyopathy undergoing septal myectomy, we assessed left ventricular outflow tract gradient relief and 1-year survival in relation to leaflet length. ResultsMedian patient age (interquartile range) was 60.3 (50.2-67.7) years, and 54.1% were male. Concomitant mitral valve repair was performed in 36 patients (6.4%), and mitral valve replacement was performed in 8 patients (1.4%), primarily for intrinsic mitral valve disease. Patients in the hypertrophic cardiomyopathy cohort had significantly longer mitral valve leaflet measurements compared with patients undergoing coronary artery bypass grafting or aortic valve replacement (P < .001 for all 3 measurements). Preoperative resting left ventricular outflow tract gradients were not related to leaflet length (<30 mm, median 49 [21, 81.5] mm Hg vs ≥30 mm, 50.5 [21, 77] mm Hg; P = .76). Further, gradient reduction after myectomy was not related to leaflet length; patients with less than 30 mm anterior leaflet length had a median gradient reduction of 33 (69, 6) mm Hg compared with 36.5 (62, 6) mm Hg for patients with leaflet length 30 mm or more (P = .36). Anterior mitral valve leaflet length was not associated with increased 1-year mortality (P = .758). ConclusionsOur study confirms previous findings that patients with hypertrophic cardiomyopathy have slight (5 mm) elongation of mitral valve leaflets. In contrast to other reports, increased anterior mitral valve leaflet length was not associated with higher left ventricular outflow tract gradients. Importantly, we found no significant relationship between anterior mitral valve leaflet length and postoperative left ventricular outflow tract resting gradients or gradient relief. Thus, in the absence of intrinsic mitral valve disease, transaortic septal myectomy with focus on extending the excision beyond the point of septal contact is sufficient for almost all patients.

Edge-to-Edge Repair Versus Secondary Cord Cutting During Septal Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy: A Pilot Randomised Study

To evaluate whether the Alfieri technique improves clinical and haemodynamic results and compare it with transaortic mitral valve secondary cord cutting in patients scheduled for septal myectomy for severely symptomatic hypertrophic obstructive cardiomyopathy. Forty-eight (48) patients with moderate-to-severe systolic anterior motion (SAM)-mediated mitral regurgitation were randomly assigned to the Alfieri or Cutting groups in addition to septal myectomy. The primary endpoint was postoperative mean transmitral pressure gradient (TPG). The secondary endpoints were residual left ventricular outflow tract (LVOT) gradient after procedure, residual mitral regurgitation (MR), postoperative SAM, repeating bypass, and survival. There were no 30-day mortality and ventricular septal defects. The postoperative LVOT gradient was 15.4±7.6 mmHg and 11.1±4.9 mmHg (p=0.078) in the Alfieri and Cutting groups, respectively. The Alfieri technique was associated with higher peak (7.8±3.3 vs 4.7±2.8 mmHg; p=0.014) and mean (3.9±1.7 vs 2.1±1.6 mmHg; p=0.013) TPG. The Cutting group was associated with higher mild MR rate at discharge (six vs no patients; p=0.009). One (1) patient (4.2%) in the Alfieri group required pacemaker implantation owing to conduction disturbances (p=0.312). Two-year (2-year) freedom from late mortality and sudden cardiac death rates were 95.5%±4.4% and 100% for the Alfieri and Cutting groups, respectively (log rank, p=0.317). No patients had New York Heart Association functional class III or IV or moderate or severe MR. The maximum LVOT gradient was 20.4±15.2 mmHg and 16.7±10.4 mmHg, respectively (p=0.330). There were no reoperations during follow-up. Both techniques with septal myectomy effectively eliminated SAM-induced MR and LVOT obstructions in hypertrophic cardiomyopathy patients.

Myectomy versus alcohol septal ablation in patients with hypertrophic obstructive cardiomyopathy.

There is very little evidence comparing the safety and efficacy of alcohol septal ablation versus septal myectomy for a septal reduction in patients with hypertrophic obstructive cardiomyopathy. This study aimed to compare the immediate and long-term outcomes of these procedures. Following propensity score matching, we retrospectively analysed outcomes in 105 patients who underwent myectomy and 105 who underwent septal ablation between 2011 and 2017 at 2 reference centres. The mean age was 51.9 ± 14.3 and 52.2 ± 14.3 years in the myectomy and ablation groups, respectively (P = 0.855), and postoperative left ventricular outflow tract gradients were 13 (10-19) mmHg vs 16 (12-26) mmHg; P = 0.025. The 1-year prevalence of the New York Heart Association class III-IV was higher in the ablation group (none vs 6.4%; P = 0.041). The 5-year overall survival rate [96.8% (86.3-99.3) after myectomy and 93.5% (85.9-97.1) after ablation; P = 0.103] and cumulative incidence of sudden cardiac death [0% and 1.9% (0.5-7.5), respectively P = 0.797] did not differ between the groups. The cumulative reoperation rate within 5 years was lower after myectomy than after ablation [2.0% (0.5-7.6) vs 14.6% (8.6-24.1); P = 0.003]. Ablation was associated with a higher reoperation risk (subdistributional hazard ratio = 5.9; 95% confidence interval 1.3-26.3, P = 0.020). At follow-up, left ventricular outflow tract gradient [16 (11-20) vs 23 (15-59) mmHg; P < 0.001] and prevalence of 2+ mitral regurgitation (1.1% vs 10.6%; P = 0.016) were lower after myectomy than after ablation. Both procedures improved functional capacity; however, myectomy better-resolved classes III-IV of heart failure. Septal ablation was associated with higher reoperation rates. Myectomy demonstrated benefits in gradient relief and mitral regurgitation elimination. The results suggest that decreasing rates of myectomy procedures need to be investigated and reconsidered.

Echocardiographic predictors of reoperation for subaortic stenosis in children and adults.

Subaortic stenosis (SAS) can present as various types of obstruction of the left ventricular outflow tract (LVOT) below the level of the aortic valve. Even though corrective surgery has been identified as the most effective treatment, SAS more frequently reoccurs requiring reoperation in a significant proportion of the patients. Previous studies have focused on predictors of recurrence in various subgroups of patients with SAS, but rarely in the overall population of patients with SAS. The aim of this study was to determine the predictors of recurrence of SAS after initial corrective surgery. Patients from the database of the Congenital Cardiology Department of the University Hospital of Southampton with significant SAS requiring corrective surgery were included in the study. Data retrieved were obtained and used to determine the predictors of SAS recurrence after the initial corrective surgery. Eighty-two patients (paediatric, n = 72 and adult, n = 10) who underwent initial successful resection were included in the analysis. Thirty patients required reoperation for recurrent SAS. These were significantly younger (median age 3.0 vs 6.7 years, P = 0.002). The recurrence of SAS was more common in patients with an interrupted aortic arch (23.3% vs 3.8%, P = 0.010) and unfavourable left ventricle geometry (43.3% vs 7.6%, P < 0.001), with steeper aortoseptal angle (131.0° ± 8.7° vs 136.1° ± 8.6°, P = 0.030), shorter distance between the point of obstruction of the LVOT and the aortic valve annulus in systole and diastole (median 4.30 vs 5.90 mm, P = 0.003 and 3.65 vs 4.95 mm, P = 0.006, respectively) and in those who had higher residual peak and mean LVOT gradients postoperatively (29.3 ± 16.0 vs 19.8 ± 10.7 mmHg, P = 0.006 and 15.9 ± 8.3 vs 10.1 ± 5.8 mmHg, P = 0.002, respectively). Overall, the presence of an interrupted aortic arch [odds ratio (OR) 10.34, 95% confidence interval (CI) 1.46-73.25; P < 0.019] and unfavourable left ventricle geometry (OR 10.42, 95% CI 1.86-58.39; P < 0.008) could independently predict reoperation for SAS after initial successful resection. Patients who have initial corrective surgery for SAS at a younger age, unfavourable left ventricle geometry, an interrupted aortic arch and higher early postoperative LVOT gradients are more likely to have recurrent SAS requiring reoperation.

Right Mini-Thoracotomy Subaortic Membrane Resection.

Subaortic membrane is an anatomical intracardiac anomaly that may cause discrete subaortic stenosis and aortic insufficiency. Patients requiring subaortic membrane resection may benefit from a minimally invasive approach; however, subaortic membranes are typically resected through a median sternotomy. We present our initial clinical experience of adult patients who have undergone a mini-thoracotomy subaortic membrane resection. Eight patients who underwent an elective subaortic membrane resection performed through a mini-thoracotomy were retrospectively reviewed. A 5-cm mini-thoracotomy incision was made in the 2nd intercostal space; a videoscope was inserted through a separate incision within the same interspace. Cardiopulmonary bypass (CPB) was instituted via central arterial and peripheral venous cannulation and an aortotomy was made. The subaortic membrane was resected with shafted instruments. The left ventricular outflow tract was inspected and CPB was weaned. Thirty-day mortality, intensive care and hospital length of stay, ventilation time, operative times, postoperative morbidity, and need for additional procedures were evaluated. The median CPB and cross-clamp times were 60 and 42 minutes, respectively. The median time to extubation was 3.6 hours. The median intensive care unit and hospital stay were 22 hours and 3 days, respectively. The postoperative left ventricular outflow tract mean gradients decreased significantly (26.5 vs. 9.4 mm Hg, P = 0.001). There were no conversions to sternotomy, perioperative strokes, or 30-day mortality. Subaortic membranes can be resected through a mini-thoracotomy approach with excellent clinical results.

Medical Management (β Blocker ± Disopyramide) of Left Ventricular Outflow Gradient Secondary to Systolic Anterior Motion of the Mitral Valve After Repair

Systolic anterior motion of the mitral valve (SAM) occurs intraoperatively after mitral valve repair (MVRr) in up to 14% of cases and typically resolves in the operating room with conservative measures. Less commonly SAM may also occur in the early or late postoperative period. The clinical course and optimal management of such cases is poorly defined, but reoperation is common. We describe our experience using disopyramide to successfully treat postoperative SAM refractory to beta blockade. Seven patients were retrospectively identified with mitral valve prolapse who underwent MVRr from 2003 to 2015 and were found during follow-up to have severe SAM with a left ventricular outflow tract (LVOT) gradient not observed intraoperatively. All 7 patients were successfully managed medically. In 5 cases, SAM persisted even after maximization of beta blockade, and the addition of disopyramide led to significant improvement or resolution of SAM, the LVOT gradient, and mitral regurgitation. The postoperative LVOT gradient initially exceeded 30mm Hg in 6 of 7 patients. In 2 patients, the LVOT gradient exceeded 100mm Hg, and both were managed medically with disopyramide with complete resolution of SAM. In conclusion, SAM after MVRr typically follows a benign clinical course and can be managed medically in most cases. When an initial treatment strategy of beta blockade is insufficient, the addition of disopyramide can effectively alleviate and terminate this condition and should be considered before reoperation.

Assessment of the Melody valve in the mitral position in young children by echocardiography

ObjectivesMitral valve replacement (MVR) in young children is limited by the lack of small prostheses. Our institution began performing MVR with modified, surgically placed, stented jugular vein grafts (Melody valve) in 2010. We sought to describe key echocardiographic features for pre- and postoperative assessment of this novel form of MVR. MethodsThe pre- and postoperative echocardiograms of 24 patients who underwent Melody MVR were reviewed. In addition to standard measurements, preoperative potential measurements of the mitral annulus were performed whereby dimensions were estimated for Melody sizing. A ratio of the narrowest subaortic region in systole to the actual mitral valve dimension (SubA:MV) was assessed for risk of postoperative left ventricular outflow tract obstruction (LVOTO). ResultsMelody MVR was performed at a median of 8.5 months (5.6 kg) for stenosis (5), regurgitation (3), and mixed disease (16). Preoperatively, actual mitral z scores measured hypoplastic (median −3.1 for the lateral [lat] dimension; −2.1 for the anteroposterior [AP] dimension). The potential measurements often had normal z scores with fair correlation with intraoperative Melody dilation (ρ = 0.51 and 0.50 for lat and AP dimensions, respectively, both P = .01). A preoperative SubA:MV <0.5 was associated with postoperative LVOTO, which occurred in 4 patients. Postoperatively, mitral gradients substantially improved, with low values relative to the effective orifice area of the Melody valve. No patients had significant regurgitation or perivalvar leak. ConclusionsPreoperative echocardiographic measurements may help guide intraoperative sizing for Melody MVR and identify patients at risk for postoperative LVOTO. Acute postoperative hemodynamic results were favorable; however, ongoing assessment is warranted.

Predictors of Outcome After Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy: An Echocardiography and Cardiovascular Magnetic Resonance Imaging Study.

Alcohol septal ablation (ASA) is used for treatment of medically refractory hypertrophic obstructive cardiomyopathy patients with severe left ventricular outflow tract (LVOT) obstruction. The current recommendations restrict the procedure to adults with favorable anatomy and no other coexisting surgically amenable disease. Some patients remain symptomatic with residual LVOT obstruction, thus better patient selection is required. One-hundred and two consecutive subjects with hypertrophic obstructive cardiomyopathy who underwent cardiovascular magnetic resonance imaging, transthoracic echocardiography, and ASA were enrolled in this study. Successful ASA was defined as reduction of LVOT gradient ≥50% of baseline by echocardiographic follow-up 6 months post ASA. The relationships between segmental thickness assessed by cardiovascular magnetic resonance imaging and echocardiography and outcomes of ASA were compared between the 2 groups. The survival rate after ablation was 100% at 6-month follow-up. The LVOT gradient decreased ≥50% of baseline in 72% (73/102) patients. There were good correlations between the reduction of postoperative LVOT gradient and the thickness of basal anterior segment (r=0.371; P<0.001), basal anteroseptal segment (r=0.527; P<0.001), and total thickness of the above 2 segments (r=0.672; P<0.001). The area under the receiver operating curves were 0.68, 0.79 and 0.89 for predictive analysis (all P<0.001). The cutoff thickness of the segment 1+2 was 50.9 mm, which yielded a sensitivity of 86% and specificity of 77%. Both echocardiography and cardiovascular magnetic resonance imaging can be used effectively as noninvasive tools for patient selection for ASA procedure. A significantly thickened septum among hypertrophic obstructive cardiomyopathy patients may be associated with a poor outcome after ASA.

Bimanual examination for septal myectomy for hypertrophic cardiomyopathy.

Left ventricular septal myectomy is the therapeutic 'gold standard' for patients with obstructive hypertrophic cardiomyopathy whose symptoms are refractory to medical therapy. We describe our initial clinical experience with a new surgical technique for septal myectomy utilizing the 'bimanual examination' in order to more reliably complete extended septal myectomy during cardioplegic arrest. The bimanual examination was performed by inspecting the interventricular septum with two fingers inserted through the aortotomy (left index finger) and a small right atriotomy (right index finger). From January 2012 to February 2014, septal myectomy was performed in 35 patients. The mean patient age was 59.6 ± 13.7, and 60% were men. Systolic anterior motion was present in 30 (86%) patients. Most patients (94%) had moderate to severe mitral regurgitation (mean 2.1 ± 0.9). Of these, 16 (46%) underwent a concomitant mitral procedure. A total of 12 (34%) consecutive patients had bimanual examination utilized during extended myectomy. Patients were grouped into a standard (n = 23) and bimanual group (n = 12). There were no significant differences between groups with respect to age, gender or New York Heart Association class. No mortality occurred. The bimanual group demonstrated a trend towards a lower postoperative left ventricular outflow tract gradient, compared with the standard group (2.5 ± 5.7 vs 7.4 ± 8.8 mmHg, P = 0.07), without the need for repeat cardiopulmonary bypass for inadequate myectomy/residual systolic anterior motion in any patient. Among those without organic mitral disease, the completeness rate of septal myectomy, defined by the percentage of patients avoiding mitral replacement, with residual systolic anterior motion or left ventricular outflow tract gradient greater than 20 mmHg, was 73 and 90% in the standard and bimanual group, respectively. Our early clinical experience of bimanual examination for septal myectomy has proved to be clinically valuable. This technique should be utilized in order to facilitate a determined and well-performed myectomy.

Modified Single-Patch Compared With Two-Patch Repair of Complete Atrioventricular Septal Defect

We compared the outcomes of modified single-patch and two-patch surgical repair of complete atrioventricular septal defect (CAVSD) on left ventricular outflow tract (LVOT) diameter and on left atrioventricular valve (LAVV) coaptation. We reviewed retrospectively postoperative 2-dimensional echocardiograms of all CAVSD patients who underwent modified single-patch or two-patch repair between 2005 and 2011. We measured the leaflet coaptation length of the LAVV in the apical four-chamber view. The LVOT was measured in the long axis view. Fifty-one patients underwent CAVSD repair at a median age of 4 months (range, 1 to 9 months) (single-patch, n=29; two-patch, n=22). The images from 46 echocardiograms were adequate for analysis. Modified single-patch repair required significantly shorter bypass time (102.0±33.6 vs 152.9±39.5 minutes, p<0.001) and ischemic time (69.0±21.7 vs 106.9±29.7 minutes, p<0.001) than did two-patch repair. The indexed coaptation length of the septal and lateral leaflets was not different between single-patch and two-patch (3.1±2.3 vs 4.1±3.1 mm/m2, p=0.25; 2.3±2.3 vs 3.3±3.0 mm/m2, p=0.21). Indexed LVOT diameter was not different in the two groups (26.1±5.2 vs 28.5±7.1 mm/m2, p=0.22). There was no hospital or late death during the median follow-up time of 35 months (range, 1 to 69 months). Five patients underwent reoperation after single-patch repair (3 with residual ventricular septal defect [VSD] and LAVV regurgitation, 1 with residual VSD, 1 with pacemaker implantation). After the two-patch repair, 1 patient required reoperation for a residual VSD and right atrioventricular valve regurgitation (p=0.22). The modified single-patch repair was performed with significantly shorter bypass time and myocardial ischemic time. The postoperative LVOT diameter and LAVV leaflet coaptation length were not significantly different between techniques.

Predictors of Reintervention After Repair of Interrupted Aortic Arch With Ventricular Septal Defect

Left ventricular outflow tract obstruction after neonatal repair of interrupted aortic arch with ventricular septal defect may warrant reintervention. We sought to identify clinical and preoperative echocardiographic predictors of reintervention for postoperative left ventricular outflow tract obstruction. Retrospective data were collected on neonates with interrupted aortic arch with ventricular septal defect who underwent single-stage repair from 1995 to 2009. Univariate and multivariate analyses were performed to identify predictors of reintervention. Seventy patients underwent repair, with 16 patients requiring reintervention: 8 underwent surgical reintervention, 5 underwent percutaneous reintervention, and 3 underwent both. The median time to reintervention was 1.2 years (range, 0.2 to 7.7). All surgical reoperations involved subaortic resection, and all percutaneous reinterventions included balloon aortic valve dilation. Several preoperative echocardiographic measurements were significant by univariate analysis; however, smaller preoperative aortic root size was an independent predictor (p = 0.02) by multivariate analysis. Patients with an aortic root size less than 6.5 mm were at greater risk for reintervention compared with patients with a root size greater than 6.5 mm (reintervention rate 44% and 12%, respectively; p < 0.001). Postoperative left ventricular outflow tract gradient by echocardiogram before discharge was significantly higher in the reintervention group. Preoperative aortic root size predicts reintervention for postoperative left ventricular outflow tract obstruction after single-stage repair of interrupted aortic arch with ventricular septal defect. Patients with elevated left ventricular outflow tract gradients at discharge are at higher risk of having progressive obstruction and require closer follow-up to ensure early identification and management.

Aortic Translocation Using the Hemi-Mustard Procedure for Corrected Transposition

The management of congenitally corrected transposition of the great arteries and associated lesions is frequently challenging. Restrictive ventricular septal defect and mild pulmonary stenosis are contraindications to the double switch procedure, including the atrial-Rastelli switch procedure, due to the production of postoperative left ventricular outflow tract obstruction. We describe a case of aortic translocation using the hemi-Mustard procedure after left ventricular training in order to prevent postoperative left ventricular outflow obstruction.

The Surgical History, Management, and Outcomes of Subaortic Stenosis in Adults

Subaortic stenosis (SAS) is a curtain of tissue involving the subaortic region, the aortic and mitral valves, the septum, and the fibrous trigones. Little is known of its course or the outcomes of its surgical management in adults. We reviewed our experience of the surgical management of SAS in adults from 1999 to 2010. We divided patients into three groups: (1) those presenting for first-time SAS resection (6 patients, 4 male, median age of 46.9 ± 17 years, mean follow-up of 5 ± 2.7 years); (2) those requiring redo resection of SAS without organic aortic valve dysfunction (8 patients, 3 male, median age of 25.3 ± 5 years, mean follow-up of 8 ± 3.08 years); and (3) those with SAS and aortic valve dysfunction (8 patients, 4 males, median age of 34.8 ± 12 years, mean follow-up of 4.5 ± 2.5 years; 5 had previous SAS surgery). Patients underwent extensive excision of the SAS, release of the fibrous trigones, and a septal myectomy if required. There was 1 early death in group 2 and 1 in group 3. In group 3, 1 patient underwent the Ross procedure and 7 patients had mechanical valve implantation. No patient required permanent pacemaker implantation. Overall follow-up was 3.3 ± 3 years (range, 6 months to 10 years). The preoperative left ventricular outflow tract gradient ranged from 40 to 120 mm Hg, and the postoperative left ventricular outflow tract gradient ranged from 0 to 16 mm Hg. At latest follow-up, no patient in groups 1 or 2 had greater than mild native aortic regurgitation. Subaortic stenosis resection in adults can successfully relieve left ventricular outflow tract obstruction, with low mortality. The complexity of SAS increases with time; therefore a longer duration of follow-up is needed to further validate our conclusions.

Rapid Two-stage Versus One-stage Surgical Repair of Interrupted Aortic Arch with Ventricular Septal Defect in Neonates

The optimal management of interrupted aortic arch (IAA) with ventricular septal defect is controversial. The aim of this study was to evaluate our 12 years of experience of surgical outcomes of one-stage and rapid two-stage total corrections of IAA with ventricular septal defect and to delineate the management of postoperative complications. We reviewed the medical charts of all patients from 1996 to 2007. Neonates with inherent complex anatomy were excluded. There were 26 patients in our series, with 11 type A and 15 type B IAA. Nineteen patients received one-stage repair and seven patients received rapid two-stage total correction. Rapid two-stage total correction was defined as two operations performed within 1 week. The 1-month postoperative survival rate was 81% (21/26), with 79% (15/19) in the one-stage group, and 86% (6/7) in the rapid two-stage group. The rapid two-stage group had a shorter cardiopulmonary bypass time (160.1 +/- 58.4 vs. 216.8 +/- 73.7 minutes, p = 0.054) and aortic cross clamp (AXC) time (65.6 +/- 24.4 vs. 91.8 +/- 22.4 minutes, p = 0.022) than the one-stage group. Postoperative left ventricular outflow tract obstruction (LVOTO) and aortic arch restenosis were common in survivors, with frequencies of 48% (10/21) and 71% (15/21) respectively. Within the postoperative arch stenosis subgroup, nine out of 15 patients received balloon angioplasties, which proved effective after only one treatment. The overall late survival rate was 73% (19/26), with 68% (13/19) in the one-stage group, and 86% (6/7) in the rapid two-stage group. The outcome of rapid two-stage repair is comparable to that of one-stage repair. Rapid two-stage repair has the advantages of significantly shorter cardiopulmonary bypass duration and AXC time, and avoids deep hypothermic circulatory arrest. LVOTO remains an unresolved issue, and postoperative aortic arch restenosis can be dilated effectively by percutaneous balloon angioplasty.

Left ventricular outflow tract obstruction after arterial switch operation

Postoperative left ventricular outflow tract obstruction (LVOTO) after arterial switch operation (ASO) is rare. In this retrospective study, we reviewed the cases of 10 patients with LVOTOs post-ASO and analyzed the options used for the LVOTOs corrections and the patients' outcomes. From December 1982 to December 2006, 1689 consecutive ASO were performed. Ten patients presented with postoperative LVOTOs (0.59% of all ASO and 7.62% of ASO for Taussig-Bing anomaly (TBA)) leading to reoperations. Before ASO they presented with significant subaortic gradients (n=4) or predisposing anatomical features (n=9) such as: conal septum malalignment (7/9), abnormal tricuspid cords insertions (4/9), muscular bundle hypertrophy (3/9) and mitral accessory tissue (2/9). No patient was lost in the follow-up: 117+/-33 months. Subaortic gradients had developed between 5 months and 14 years after ASO (mean 41+/-35 months) leading to reoperations. Most LVOTOs post-ASO were due to fibrotic membranes or fibro-muscular hypertrophy, removed at first reoperation. After their first reoperations, seven patients (70%) had non-significant or low gradients and were not reoperated for LVOTO. Three patients underwent iterative surgical procedures for LVOTOs leading to two aortic valve replacements associated with LVOTO release or Konno procedure. Postoperative LVOTO after ASO is rare but happens more frequently in TBA. Most of them can benefit from resections of subaortic obstacles or septal plasties. In more complex cases iterative surgical procedures may lead to complications such as block or severe aortic valve regurgitation.

Geometry of the left ventricular outflow tract in fixed subaortic stenosis and intact ventricular septum: An echocardiographic study in children and adults

We compared the echocardiographic geometry of the preoperative and postoperative left ventricular outflow tract in children and adults with isolated fixed subaortic stenosis with age- and weight-matched controls to elucidate whether the geometry can be modified when surgical intervention is performed at a younger age. The mitral-aortic valve distance, aortic valve diameter, aorto-left ventricular septal angle, degree of aortic valve dextroposition, aortic valve-subaortic stenosis distance, width of left ventricular outflow tract, left ventricle wall thickness, and septal thickness were determined preoperatively and postoperatively in 21 patients and 21 controls. The measurements were indexed to body surface area. Patients were divided into 3 age groups: group 1 comprised 9 patients aged 1 to 10 years, group 2 comprised 8 patients aged 11 to 20 years, and group 3 comprised 4 patients aged 21 years or more. Compared with controls, patients had a significantly wider mitral-aortic separation (group 1, P = .003; group 2, P = .02), a steeper aortoseptal angle (group 1, P = .02; group 3, P = .03), a smaller left ventricular outflow tract width (group 1, P = .003; group 2, P = .01), a marked aortic valve dextroposition (groups 1 and 3), an increased left ventricle wall thickness (group 1, P = .03), and an increased septal thickness (group 1, P = .01). There was a significant difference between preoperative and postoperative values in aortoseptal angle and left ventricular outflow tract width in patients up to 10 years of age (P = .02 and P = .01, respectively). Hearts with isolated subaortic stenosis have abnormal left ventricular outflow tract geometry that postoperatively showed changes in left ventricular outflow tract width and aortoseptal angle. Compared with controls, the aortoseptal angle does not "normalize" when surgery is performed in older patients, suggesting that left ventricular outflow tract geometry may be remodeled in younger patients.

Discrete Subaortic Stenosis: Long-Term Prognosis on the Progression of the Obstruction and of the Aortic Insufficiency

We sought to determine the long-term rate of progression of left ventricular outflow tract (LVOT) obstruction and aortic insufficiency (AI) in adult patients operated on for discrete subaortic stenosis (DSS). Between 1975 and 1995, 52 patients underwent surgery for DSS; their mean age was 25.4 +/- 14.8 years. Mean preoperative LVOT gradient was 72.8 +/- 25.7 mm Hg. Excision of the subaortic membrane was carried out in all patients, myectomy of the interventricular septum was additionally carried out in 8 patients (15.4 %), and aortic valve replacement (AVR) was performed in 15 patients (28.8 %). There were 2 operative deaths (3.8 %). Early postoperative LVOT gradient was 9.7 +/- 6.5 mm Hg. Follow-up ranged from 8.1 to 26.6 years. There were 8 late deaths (16.3 %), and mean LVOT gradient was 13.3 +/- 10.7 mm Hg. Five patients required reoperation for recurrent obstruction; 4 patients had a gradient of more than 30 mm Hg. The AI, in patients who did not undergo aortic valve replacement, did not substantially change during follow-up. DSS is a variable, unpredictable and progressive disease; recurrent obstruction may reappear despite the adequacy of surgical excision, and is not related to preoperative gradient. Mild AI remains substantially unchanged and AVR is indicated in severe AI.