Pulmonary valve preservation and restoration strategies for repair of tetralogy of Fallot.

Despite tremendous advances in surgical treatment of tetralogy of Fallot, augmenting the small right ventricular outflow tract remains a challenge. Transannular patch augmentation revolutionised surgical management, but did so at the expense of rendering patients with pulmonary insufficiency and the resulting problems associated therewith. Recent surgical efforts have focused on pulmonary valve preservation at initial correction and pulmonary valve restoration after transannular patching, with favourable results. In this manuscript, we review methods of pulmonary valve preservation and restoration.

The balloon dilation of the pulmonary valve during early repair of tetralogy of Fallot.

BACKGROUND AND OBJECTIVE: Progressive pulmonary valve (PV) regurgitation leads to right ventricular failure after repair of tetralogy of Fallot (TOF). We sought to evaluate our results with the preservation of the PV in selected patients with TOF. METHODS: All patients with TOF who were scheduled for PV's preservation between June 2007 and May 2010 were enrolled. Surgical correction involved the combination of early transatrial repair and intraoperative balloon dilation of the PV annulus. RESULTS: Of 18 patients, 16 (89%) underwent a successful preservation of the PV. Median age at surgery was 3.1 months (range 2.4-4.7 months). Median preoperative PV Z-score was -2.5 (range -1.4 to -3.12) and the median peak right ventricle outflow tract (RVOT) gradient was 80 mm Hg (range 49-90 mm Hg). No procedure-related complications were reported. The size of the PV annulus after the balloon dilation was appropriate for body surface area in all patients. Median follow-up time was 1.4 years (range 0.5-3.3 years). Reoperation was needed in one patient 3 months after repair because of residual subvalvar RVOT obstruction. The remaining 15 patients are alive and well. The median PV Z-score is 0 (range -0.2 to 1). Median peak RVOT gradient is 20 mm Hg (range 12-32 mm Hg). The PV is competent in seven patients; mild PV regurgitation is present in seven patients and moderate in one. CONCLUSIONS: The integrity of the PV annulus and PV function can be preserved in selected patients during early repair of TOF when using concomitant balloon dilation. The PV preservation will hopefully prevent long-standing RV dysfunction.

Valve-sparing options in tetralogy of Fallot surgery.

Given late outcomes of patients with tetralogy of Fallot repaired in the 1970s and 1980s, as well as a better understanding of the late deleterious effects of pulmonary regurgitation, there is a tendency toward preservation of the pulmonary valve function during primary repair of tetralogy of Fallot. The bar keeps moving downward, to include smaller and more dysmorphic pulmonary valves. This article reviews some useful indications and techniques for valve-sparing options, including intraoperative balloon dilation and cusp reconstruction using a patch. Just like other valve repair techniques, no one technique can be applied uniformly, and surgeons must master a wide armamentarium of techniques.

Long-term results of pulmonary valve annular enlargement with valve repair in tetralogy of Fallot.

OBJECTIVES: We adopted an operative technique of pulmonary valve (PV) annular enlargement with valve repair in tetralogy of Fallot (TOF) correction to reduce postoperative pulmonary regurgitation (PR) 16 years ago. Here, we have evaluated the long-term results. METHODS: Between April 2000 and August 2005, 43 patients (26 men) with tetralogy of Fallot with pulmonary stenosis underwent PV annular enlargement with valve repair. The median age and body weight at the time of surgery were 14 months and 10.2 kg, respectively. RESULTS: There was no operative mortality. Mean postoperative PR grade at discharge was 0.93 ± 0.40 (none or trivial in 10 patients, mild in 27 patients, mild to moderate in 5 patients and moderate in 1 patient), and the mean postoperative pressure gradient across PV was 13.0 ± 10.9 mmHg. The mean follow-up duration was 131.9 ± 42.9 months. During follow-up, 1 reoperation was performed for residual ventricular septal defect. The mean PR grade at the last follow-up echocardiography was 1.59 ± 0.60 (mild in 17 patients, mild to moderate in 8 patients, moderate in 14 patients, moderate to severe in 1 patient and severe in 3 patients), and the mean pressure gradient was 22.7 ± 9.9 mmHg. We have compared the incidence of moderate or more PR with the incidence of patients who underwent simple transannular patch enlargement through propensity score matching. The PV repair group had a lower incidence of moderate or more PR compared with the simple transannular patch group (40% vs 68%, P = 0.04). CONCLUSIONS: PV annular enlargement with valve repair has reasonable long-term results and yields a lower long-term incidence of significant PR compared with the simple transannular patch enlargement technique.

Surgical strategies protecting against right ventricular dilatation following tetralogy of Fallot repair.

BACKGROUND: Right ventricular (RV) volume overload increases morbidity and mortality after tetralogy of Fallot (TOF) repair. Surgical strategies like pulmonary leaflets sparing and tricuspid valve repair at time of primary repair may decrease RV overload. Our objective is to evaluate early and midterm results of pulmonary leaflets sparing with infundibular preservation and tricuspid valve repair in selected TOF patients with moderate pulmonary annular hypoplasia. METHODS: From 2011 to 2016; 46 patients with TOF and moderate pulmonary annular hypoplasia had surgical repair with sparing of the pulmonary valve leaflets. Concomitant tricuspid valve repair was performed in 33 patients (71.8%). Mean age was 13.1 ± 4.8 months, 68% were males (n = 31) and mean weight was 9.5 ± 2.3 kg. Preoperative McGoon ratio was 1.9 ± 0.4 and pulmonary valve z-score ranges from - 2 to - 3. Preoperative pressure gradient of RVOT was 80.9 ± 7.7 mmHg and 10.9% had minor coronary anomalies (n = 5). RESULTS: All repairs were performed through trans-atrial trans-pulmonary approach. 87% had pulmonary valve commissurotomy (n = 40). Mean cardiopulmonary bypass time was 71 ± 6.3 min and ischemic time 42.4 ± 4.9 min. Hospital mortality occurred in 4.3% (n = 2). Mean RVOT pressure gradient decreased significantly postoperatively (28.8 ± 7.2 mmHg, p-value< .001) and at the last follow up (23.6 ± 1.8 mmHg, p-value< .001). Pulmonary regurgitation progressed by one grade in 2 patients compared to the postoperative grade. 1 patient (2.5%) had late mortality and reintervention was required in 5 patients (12.5%). CONCLUSION: Pulmonary leaflets sparing, and tricuspid valve repair are safe for TOF repair with no added morbidity or mortality. These procedures could contribute to reducing right ventricular volume overload over time after TOF repair.

Enteral immunonutrition during sepsis prevents pulmonary dysfunction in a rat model.

BACKGROUND: Sepsis often results in severe pulmonary dysfunction. Via the thoracic duct, the lung is the first organ exposed to gut-derived inflammatory mediators released into mesenteric lymph during sepsis. AIM: To investigate whether an enteral immunonutrition during sepsis improves pulmonary function. METHODS: Mesenteric lymph was obtained from lymph fistula donor rats after intra peritoneal (i.p.) saline (control lymph) or lipopolysaccharide (sepsis lymph) injection. Sepsis lymph was also collected during enteral immunonutrition with omega-3 enriched, long-chain fatty acids (SMOF lipid). Control, sepsis, or sepsis-SMOF lymph was reinfused into the jugular vein of separate recipient rats. The lungs were then harvested, stained with hematoxylin-eosin, and analyzed for: (1) perpendicular parenchyma thickness of the alveolar wall; (2) myeloperoxidase-positive cells; and (3) terminal deoxynucleotidyl transferase Biotin-dUTP nick end labeling (TUNEL)-positive cells. RESULTS: Enteral immunonutrition during sepsis reduced the release of TNFalpha into mesenteric lymph by about 4.5-fold within the first 2 h. Infusion of sepsis lymph into recipient rats induced thickening of alveolar walls, inflammatory reaction, and apoptosis. Infusion of sepsis lymph obtained during enteral immunonutrition did not cause anatomical changes, induced only a mild inflammatory reaction, and prevented apoptosis in the lungs of recipient rats. CONCLUSIONS: Mediators in sepsis lymph induce pulmonary dysfunction such as an increased distance for oxygen transport, inflammatory reaction, and apoptosis. The lung may be protected by an enteral immunonutrition containing long-chain fatty acids.

[Effects of right ventricular outflow tract reconstruction with modified autologous pericardial monocuspid valve in patients with tetralogy of Fallot: a clinical research].

OBJECTIVE: To evaluate the application value of right ventricular outflow tract (RVOT) reconstruction with an autologous pericardial monocuspid valve to prevent pulmonary regurgitation after total correction of tetralogy of Fallot (TOF). METHOD: Twenty patients suffering from TOF with pulmonary artery hypoplasia, 11 males and 9 females, aged (8.43+/-3.83), received surgical total correction with RVOT reconstruction with autologous pericardial monocuspid valve. During the operation, the RVOT was enlarged with the autologous pericardial patch, and a predesigned part of the pericardial patch was folded to form a big artificial valve, which was stitched along with the pericardial patch. Another 20 patients, 12 males and 8 females, aged (8.47+/-3.94), underwent traditional RVOT reconstruction with traditional pericardial monocuspid valve patch. Post-operational follow-up was conducted for 6 months. RESULTS: No surgical mortality was recorded after operation. The degree of pulmonary valve regurgitation in the research group was less than that in the control group. CONCLUSION: Modified autologous pericardial monocuspid valve can prevent pulmonary regurgitation better.

Modified Damus-Kaye-Stansel procedure using aortic flap technique for systemic ventricular outflow tract obstruction in functionally univentricular heart.

Damus-Kaye-Stansel procedure is a useful method to relieve the systemic ventricular outflow tract obstruction in functionally univentricular heart. Regurgitation of pulmonary valve and recurrence of systemic ventricular outflow obstruction are the major concerns at the late phase of this procedure. Modification of original Damus-Kaye-Stansel procedure that can prevent the use of prosthetic materials is evaluated. The modified Damus-Kaye-Stansel procedure using aortic flap technique was performed in eight patients with functionally univentricular heart. Patients' ages ranged from 3 to 28 months (mean 14 months). Follow-up period was 37 months as a mean (9-71 months), and the follow-up was complete. There was no operative mortality and no late death. In addition, there was no recurrence of systemic ventricular outflow tract obstruction throughout the follow-up period. Regurgitation of the pulmonary valve estimated by echocardiography at the latest follow-up was none to trivial in seven patients and mild in one. The modified Damus-Kaye-Stansel procedure using aortic flap technique is a safe, useful and reproducible technique to solve systemic ventricular outflow tract obstruction in functionally univentricular heart, and it can be an alternative for original technique or the so-called double-barrel modification.

The criteria for reconstruction of right ventricular outflow tract in total correction of tetralogy of Fallot.

Retrospective analysis was undertaken to determine the influence of residual pulmonary stenosis and surgically induced pulmonary insufficiency on the operative mortality rate in 104 patients with tetralogy of Fallot who underwent total correction between 1967 to 1970 at First Department of Surgery, Osaka University Hospital. This study revealed that, in order to improve the operative outcome in this anomaly, it is necessary to correct pulmonary stenosis to the point of the right-to-left ventricular peak pressure ratio (PRV/LV) less than 0.8 as well as preventing severe pulmonary insufficiency. Through this study, the criteria for enlargement of the right ventricular outflow tract (RVOT) for each given body size which will produce a PRV/LV of less than 0.8 were derived in 1971. If the size of the RVOT after infundibulectomy and valvotomy is smaller than that prescribed by the criteria, an outflow patch must be placed on the pulmonary outflow tract. Since 1971, these criteria have been used in total correction of this anomaly in our affiliated hospital without any problem and have been yielding good operative results. Postoperative hemodynamic studies have shown that our criteria are suitable.

Short-term effect of monocuspid valves on pulmonary insufficiency and clinical outcome after surgical repair of tetralogy of Fallot.

In the surgical repair of tetralogy of Fallot, monocuspid valves are sometimes inserted within a transannular patch to prevent pulmonary insufficiency. To determine whether this monocuspid valve prevents short-term postoperative pulmonary insufficiency and improves clinical outcome, we reviewed clinical data and preoperative and postoperative echocardiographic variables from 61 patients who underwent one of three different procedures for repair of tetralogy of Fallot between August 1992 and March 1994. We compared features from 24 patients who had undergone transannular patch repair with a monocuspid valve (patch-valve) with those from 17 patients who had undergone patch repair without a monocuspid valve (patch) and 20 patients who had undergone repair without a transannular patch (no patch). We used the ratio of pulmonary valve insufficiency jet width to pulmonary artery diameter, as measured by color-flow Doppler flowmetry, as an index of severity of pulmonary insufficiency. Moderate to severe pulmonary insufficiency was arbitrarily defined as a ratio of at least 0.50. We found no significant differences in ratios among the patch-valve group (0.73 +/- 0.25, mean +/- standard deviation), the patch group (0.79 +/- 0.20), and the no patch group (0.59 +/- 0.23). The percentages of patients with moderate to severe pulmonary insufficiency did not differ among the three groups (patch-valve 80%, patch 90%, no patch 64%). Clinical data (including mortality, number of reoperations, intensive care unit and hospital lengths of stay, and postoperative hemodynamics) were similar in the three groups. We conclude that insertion of a monocuspid valve in repair of tetralogy of Fallot does not prevent short-term postoperative pulmonary insufficiency and does not improve immediate postoperative outcome for these patients.

Homologous monocuspid valve patch in right ventricular outflow tract reconstruction.

BACKGROUND: In the surgical repair of tetralogy of Fallot or pulmonary atresia, pulmonary regurgitation may be detrimental in the postoperative period. We have used homograft monocuspid valve patch to prevent pulmonary insufficiency. METHODS: From September 1996 to December 1998, twenty-five patients, 4 months to 8 years of age (median 10.1 months) had homograft monocuspid valve in the procedure of right ventricular outflow tract reconstruction. The function of the monocuspid valve was assessed by echocardiogram and graded as trivial to mild, mild to moderate, moderate, and severe. We evaluated the degree of pulmonary insufficiency before discharge, at 3-6 months, and at 12 months after the operation. RESULTS: There was one hospital death due to fulminate adeno viral pneumonia. On echocardiogram, 21 patients (88%, 21/24) had no significant pulmonary insufficiency. Only one patient (4.5%) showed a moderate degree of pulmonary insufficiency. At 3-6 months, seventeen of twenty-one (81%) patients had no significant pulmonary insufficiency. There were fourteen patients who had follow-up over 1 year, and no patients showed newly developed significant pulmonary insufficiency. CONCLUSIONS: We concluded that the homograft monocuspid valve patch for right ventricular outflow tract reconstruction has provided excellent early results for the prevention of pulmonary insufficiency. However these effects are limited in duration and further close follow-up should be needed.

[Value of Naito's criteria in the surgical repair of tetralogy of Fallot]. / Intérêt des critères de Naïto dans la correction chirurgicale de la tétralogie de Fallot.

Naito suggested criteria for the optimal reconstruction of the right ventricular outflow tract in total correction of tetralogy of Fallot based on the minimum acceptable diameter of the pulmonary artery. The value of these criteria was assessed in 78 operated patients by haemodynamic measurements at surgery and 6 months after operation. Using these criteria, a ratio of right ventricular/left ventricular systolic pressure less than 0.60 was obtained with the creation of pulmonary regurgitation which was usually moderate. Long-term assessment of these results is required.

[Appetite suppressants and heart valve disorders]. / Atteintes valvulaires des anorexigènes.

Serotoninergic appetite-suppressant drugs, fenfluramine and dexfenfluramine, were withdrawn from the market in September 1997 on account of two major cardiopulmonary complications: primary pulmonary hypertension and valvular regurgitation. The valvular heart diseases involve mainly left-sided valves, and contrary to physiological valvular regurgitations, they appear mostly on the aortic valve. Prolonged exposure (> 3 months) appears to confer a higher risk of cardiac valve involvement. Pathological features are similar to carcinoid or ergot alkaloid-induced valve diseases, and suggest a common pathophysiological mechanism which would also explain pulmonary hypertension by the toxic effect of high levels of circulating serotonin. After the first reports documenting a dramatically high prevalence of valvular side effects (up to 33% according to the Food and Drug Administration), recent studies reported a lower prevalence and severity. The long-term outcome and the real incidence are unknown and require further research and epidemiological data. A clinical survey of the patients exposed to serotoninergic appetite-suppressants is necessary, to be repeated 6 to 8 months later in the absence of an initial cardiac murmur. Doppler echocardiographic examination should be performed after prolonged exposure (> 3 months) or a high dosage of these drugs, in circumstances such as the presence of cardiovascular symptoms, a cardiac murmur, or an uncertain cardiac examination because of weight of patients.

Total correction of tetralogy of Fallot: late clinical follow-up.

Forty-five years after the first repair of tetralogy of Fallot we have sufficient data to describe the post-surgical history of these patients in terms of survival, quality of life and delayed complications. The long-term results of surgical repair during infancy and childhood are good in terms of health assessment and exercise capacity. However arrhythmias and right ventricular dysfunction secondary to ventriculotomy and residual pulmonary regurgitation characterize the delayed follow-up. The identification of the clinical parameters which are predictive of premature ventricular dysfunction and electrical instability is a primary aim of clinical follow-up.

Double-barrel Damus-Kaye-Stansel operation is better than end-to-side Damus-Kaye-Stansel operation for preserving the pulmonary valve function: the importance of preserving the shape of the pulmonary sinus.

OBJECTIVE: The Damus-Kaye-Stansel operation sometimes results in deteriorating semilunar valve insufficiency. We verified the semilunar valve function after the Damus-Kaye-Stansel operation and compared the end-to-side Damus-Kaye-Stansel with the double-barrel Damus-Kaye-Stansel. METHODS: Forty-seven patients who underwent the Damus-Kaye-Stansel operation between June 1993 and August 2008 were retrospectively reviewed. Any patient who underwent a Norwood-type operation was excluded. The median age at operation was 19 months (range, 0-276 months). Forty-five patients were Fontan candidates. Thirty-nine patients underwent pulmonary artery banding before the Damus-Kaye-Stansel operation. Twenty-two patients had undergone an arch repair previously. The semilunar valve function was evaluated by echocardiography. RESULTS: Thirteen patients underwent the end-to-side Damus-Kaye-Stansel operation, and 34 patients underwent the double-barrel Damus-Kaye-Stansel operation. The mean follow-up period was 71 ± 50 months (range, 1-188 months). Although there were 4 deaths, no death was related to the Damus-Kaye-Stansel procedure. Two of the patients with early death could not undergo a postoperative evaluation of the semilunar valves. The semilunar valve regurgitation mildly deteriorated in 7 patients (pulmonary regurgitation in 5 patients and aortic regurgitation in 2 patients). Pulmonary regurgitation deteriorated from none to mild in 1 patient, none to trivial in 2 patients, and trivial to mild in 2 patients. Both deteriorations in aortic regurgitation ranged from none to trivial. Semilunar valve regurgitation did not affect patients' circulatory condition. The end-to-side Damus-Kaye-Stansel operation more frequently caused a deterioration in pulmonary regurgitation than the double-barrel Damus-Kaye-Stansel operation (4/11 vs 1/34, P = .001). No surgical intervention for a systemic ventricular outflow obstruction was observed in the follow-up period. CONCLUSIONS: The double-barrel Damus-Kaye-Stansel operation was found to be superior to the end-to-side Damus-Kaye-Stansel operation for the prevention of postoperative pulmonary regurgitation.

Outcomes of prenatally diagnosed tetralogy of Fallot: Implications for valve-sparing repair versus transannular patch.

OBJECTIVES: To assess outcomes of prenatally diagnosed tetralogy of Fallot and determine factors associated with the choice to undergo a valvesparing repair versus transannular patch, and the use of prostaglandins at birth. METHODS: All cases at The Hospital for Sick Children (Toronto, Ontario) with a fetal diagnosis of tetralogy of Fallot from 1998 to 2006, were reviewed for demographic and fetal echocardiographic data to determine factors associated with the valve-sparing repair and need for perinatal support. RESULTS: Sixty-four fetuses met inclusion criteria (median gestational age 22 weeks) with 47 live births. Twenty-six underwent valve-sparing repair (median age 5.7 months) and 14 underwent transannular patch repair (median age 4.5 months). There were seven deaths before surgery and one post-transannular patch repair. One patient required a transannular patch repair after the initial valve-sparing repair. Twelve of 29 (41%) patients received prostaglandins at birth. Type of surgical repair, use of prostaglandins and postnatal death were among the outcomes investigated. The mean pulmonary valve (PV) z-score was -3.0+/-2.0 and the mean PV/aortic valve (AoV) ratio was 0.65+/-0.10. Lower PV z-score (P=0.04), smaller PV/AoV ratio (P=0.04) and the presence of nonantegrade arterial duct flow (P=0.02) were associated with prostaglandin use. A higher PV/AoV ratio was associated with valvesparing repair (P=0.04). Fetal z-scores of the PV, AoV and right pulmonary artery at 29 to 32 weeks gestational age correlated with respective postnatal z-scores (P=0.01). CONCLUSION: Fetal echocardiographic variables were associated with the use of prostaglandins and valve-sparing repair in fetuses with tetralogy of Fallot, and at 29 weeks, correlated with postnatal valve diameters.

Pericardial monocusp for pulmonary valve reconstruction: a new technique.

Enhancing the pulmonary annulus renders the pulmonary valve incompetent in cases of tetralogy of Fallot. A pressure-loaded right ventricle may change to a volume-loaded ventricle, which may dilate and eventually dysfunction. This study evaluated a new technique of fashioning a monocusp valve from untreated autologous pericardium suspended on a transannular patch. It was assessed in 40 children undergoing complete repair of tetralogy of Fallot between January 2005 and December 2007. 24 patients had a transannular patch alone (group A) and 16 received a transannular patch with the autologous pericardial monocusp valve (group B). All patients were followed up for 1 year with transthoracic echocardiography to determine pulmonary insufficiency. There was no significant difference in cardiopulmonary bypass or aortic crossclamp times, postoperative chest tube drainage, duration of inotropic usage, intensive care unit or hospital stay between groups. Univariate analysis showed significantly lower grades of pulmonary insufficiency in group B. This technique for creating an autologous pericardial monocusp valve is an inexpensive, simple, and reliable procedure that effectively reduces pulmonary insufficiency at the 1-year follow-up.