Evaluation of ventricular septal defect repair using intraoperative transesophageal echocardiography: frequency and significance of residual defects in infants and children

The Destiny of Postoperative Residual Ventricular Septal Defects After Surgical Repair in Infants and Children

PURPOSE

Residual ventricular septal defects (rVSDs) of small size are commonly seen on transesophageal echocardiography after surgical repair. This study aimed to determine the destiny of rVSD found on intraoperative echocardiogram.

METHODS

Patients undergoing surgical repair of VSD as the primary procedure with available intraoperative and discharge echocardiograms between 2007 and 2017 were reviewed. Presence of an rVSD on intraoperative echo triggered review of discharge echo and of subsequent follow-up echocardiograms.

RESULTS

One hundred four patients were analyzed. The mean age and weight for the entire cohort were 1.4 ± 2.9 years (median, 5.4 months; range, 29 days to 14 years) and 8.8 ± 9.9 kg (median, 5.1 kg; range, 2.7-58 kg), respectively. Sixty (57%) patients had rVSD at discharge, with mean size of residual VSD of 1.38 ± 0.92 mm (mode, 0.6; median, 2.2 mm; range, 0.5-3.9 mm). The mean follow-up time was 3.7 ± 3.1 years (range, 1 month to 9.3 years). Among those with rVSD at discharge, a residual shunt persisted in 73% at one-month follow-up. On follow-up at three years postdischarge, of the 60 patients with early rVSD, 6 had a persistent rVSD (10%) with a mean diameter of 3.0 ± 0.8 mm (range, 2.4-3.9 mm).

CONCLUSIONS

Residual VSD after surgical repair is detected frequently on postoperative echocardiogram. The presence of rVSD was not associated with any preoperative, intraoperative, or postoperative factors. By three years of follow-up, only six patients continued to demonstrate rVSD with a mean diameter of 3 mm, suggesting that defects 3 mm or greater may be less likely to close spontaneously after three years.

Residual Shunts Following Isolated Surgical Ventricular Septal Defect Closure: Risk Factors and Spontaneous Closure

Although isolated congenital ventricular septal defects (VSD) can be repaired with a high degree of success, residual shunts (RS) are commonplace postoperatively. Small RS are relatively innocuous and tend to spontaneously close with time, despite the emotional burden it poses for the patient and family. A large RS, however, needs ongoing surveillance and may necessitate reintervention. Factors influencing the incidence of RS as well as the likelihood and expected timing of its spontaneous closure are discussed in this study. The patient records and relevant data of 362 consecutive patients undergoing cardiac operation with isolated congenital VSD closure as primary procedure between January 2017 and December 2017 were included in the study. Postoperative transthoracic echocardiograms were performed at hospital discharge, and during follow-up, at 1 month, 3 months, 6 months and 1 year postoperatively. Residual defects were measured under echocardiogram at every follow-up. Factors expected to be associated with RS occurrence and spontaneous closure were included for logistic and Cox regression statistical analysis. There were 113 cases where RS occurred according to the first postoperative echocardiograms that were performed at discharge, of which 80 were confirmed closed during subsequent follow-up, with a median follow-up of 96 days. A cutoff of 1.25 mm for the initial RS was found to be the best predictor of spontaneous closure at 6-month follow-up. Small shunts had higher closure rate than larger ones by a follow-up duration of 300 days, at which the two groups tended to reach a similar spontaneous closure rate. Longer surgical bypass time distinguished small from larger residual shunts measured upon discharge. Following repair of isolated congenital VSDs, the incidence of a residual shunt is high. The majority spontaneously close within 300 days following surgery. Longer bypass time predicted a larger residual shunt upon discharge. Larger than 1.25 mm shunts had lower short-term closure rate but seemed not to differ from smaller shunts beyond 300 days postoperatively.

Diagnosis of an Additional Ventricular Septal Defect by Observing Dark Blood in Aortic Root Vent: A Case Report

Diagnosis and management of multiple ventricular septal defects still remain a challenging task. Although many new diagnostic modalities have been used for the perioperative diagnosis of ventricular septal defects, the discovery of residual or additional shunts in the postoperative period is not uncommon. We report a case where we observed an undiagnosed additional ventricular septal defect shunting deoxygenated dark blood into the aortic root vent during deairing of the heart, which was confirmed on transesophageal echocardiography and addressed with reinstitution of cardiopulmonary bypass.

Tetralogy of Fallot: Everything you wanted to know but were afraid to ask

Tetralogy of Fallot (TOF) has four anatomic features: right ventricular hypertrophy (RVH), ventriculoseptal defect (VSD), overriding aorta and right ventricular outflow tract obstruction (RVOT) with an occurrence of 3.9 /10,000 births. The pathophysiologic effects in TOF are largely determined by the degree of RVOT and not the VSD. Intra-operative anesthetic management is also dependent on the degree of RVOT obstruction and influenced by the extent of surgical RVOT repair.

Effect of corrective or palliative procedures on arterial to end-tidal carbon dioxide pressure difference in pediatric cardiac surgery

BACKGROUND

The normal small difference (3-5 mmHg) between arterial (partial pressure of carbon dioxide [PaCO₂]) and end-tidal carbon dioxide pressure (ETPCO₂) increases in children with congenital heart disease. The present study was conducted to evaluate the effect of corrective or palliative cardiac surgery on this difference (known as DPCO2).

PATIENTS AND METHODS

In a prospective study, 200 children (aged <12 years old) candidate for corrective or palliative cardiac surgery were studied. Using arterial blood gas measurement and simultaneous capnography, DPCO₂ was calculated at various intra- and postoperative periods. DPCO₂ values were compared within and between corrective or palliative procedures.

RESULTS

Corrective and palliative procedures were carried out on 154 and 46 patients, respectively. Initial DPCO₂ was higher than normal values in corrective or palliative procedures (15.50 ± 13.1 and 10.75 ± 9.1 mmHg, respectively). DPCO₂ was higher in patients who underwent palliative procedure, except early after procedure. The procedure did not have any effect on the final DPCO₂ in palliative group. Although DPCO₂ decrease was significant in the corrective group, it did not return to normal values. Operation time was longer, and the need to inotropic support was higher in corrective procedures; however, longer periods of ventilatory support were needed in the palliative group. Complication rate and Intensive Care Unit stay time were the same in two operation types.

CONCLUSIONS

DPCO₂ did not change after palliative cardiac procedures. DPCO₂ decreased after corrective procedures; however, it did not return to normal values at early postoperative period. Thus, DPCO₂ may not have any clinical value in monitoring the quality of corrective or palliative procedures.

Transesophageal echocardiography experience in thepediatric age group in a tertiary cardiac center

BACKGROUND/AIM

The aim of this study was to evaluate the transesophageal echocardiography (TEE) findings of pediatric patients in a tertiary center where complex congenital heart surgery and interventional procedures have been performed.

MATERIALS AND METHODS

All TEE studies performed between December 2009 and December 2014 were reviewed retrospectively. Patients were divided into 3 groups: perioperative, during interventional procedures, and due to other reasons. Demographic features, transthoracic echocardiography (TTE) reports, TEE reports, change in decision after TEE evaluation, and related complications were recorded.

RESULTS

A total of 703 patients who had TEE evaluation were included in the study; 51% were female and 49% were male. The median age was 90 months (2 months to 18 years). TEE was performed perioperatively in 430 patients (61%), during cardiac catheterization-angiography and electrophysiology studies in 181 patients (26%), and due to other reasons in 92 patients (13%). Mismatches between TTE and TEE or changes in decision after TEE evaluation were present in 45 patients (10.4%) who had perioperative TEE, in 10 patients (5.5%) who had TEE during interventional procedures, and 22 patients (24%) who had TEE evaluation due to other reasons. No major complications were detected.

CONCLUSION

Information acquired by TEE increases the clarity of future plans for the patient and helps to decrease the mortality and morbidity caused by unnecessary procedures.

Accuracy of transesophageal echocardiography in the identification of postoperative intramural ventricular septal defects

BACKGROUND

Intramural ventricular septal defects (VSDs), residual interventricular communications occurring after repair of conotruncal defects, are associated with poor postoperative outcomes. The ability of intraoperative transesophageal echocardiography (TEE) to identify intramural VSDs has not yet been evaluated.

METHODS

Intraoperative TEE and postoperative transthoracic echocardiography (TTE) data in all patients undergoing all biventricular repair of conotruncal anomalies in our hospital between January 1, 2006, and June 30, 2013, were reviewed. The ability of TEE to accurately identify residual defects was assessed using postoperative TTE as the reference imaging modality.

RESULTS

Intramural VSDs occurred in 34 of 337 patients evaluated; 19 were identified by both TTE and TEE, and 15 were identified by TTE only. Sensitivity was 56% and specificity was 100% for TEE to identify intramural VSDs. Peripatch VSDs were identified in 90 patients by both TTE and TEE, in 53 by TTE only, and in 15 by TEE only, yielding a sensitivity of 63% and specificity of 92%. Of the VSDs requiring catheterization or surgical reintervention, 6 of 7 intramural VSDs and all 5 peripatch VSDs were identified by intraoperative TEE. TEE guided the intraoperative decision to return to cardiopulmonary bypass (CPB) in an attempt to close residual defects in 12 patients with intramural VSDs and in 4 patients with peripatch VSDs seen after initial CPB; of these, 10 intramural VSDs and all 4 peripatch VSDs resolved or became smaller on final intraoperative TEE.

CONCLUSIONS

TEE has modest sensitivity but high specificity for identifying intramural VSDs and can detect most defects requiring reintervention. Repeat attempts at closure in the index operation may successfully correct intramural VSDs identified by TEE.

Intramural Ventricular Septal Defect Is a Distinct Clinical Entity Associated With Postoperative Morbidity in Children After Repair of Conotruncal Anomalies

BACKGROUND

Intramural ventricular septal defects (VSDs) are interventricular communications through right ventricular free wall trabeculations that can occur after repair of conotruncal anomalies. We assessed the prevalence of residual intramural VSDs and their effect on postoperative course.

METHODS AND RESULTS

Children who underwent biventricular repair of a conotruncal anomaly from January 1, 2006, to June 30, 2013, and had a postoperative transthoracic echocardiogram were included. Images were reviewed for residual intramural or nonintramural VSDs. The primary outcome was a composite of mortality, extracorporeal membrane oxygenation use, and need for subsequent catheter or surgical VSD closure. The secondary outcome was postoperative hospital length of stay. A residual VSD was present in 256 of the 442 subjects (58%), of which 231 (90%) were <2 mm in size. Forty-nine patients (11%) had intramural VSDs, and 207 (47%) had nonintramural VSDs. Patients with intramural VSDs were more likely to reach the primary composite outcome compared with those with nonintramural VSDs or no residual VSD (14 of 49 [29%] versus 15 of 207 [7%] versus 6 of 186 [3%]; P<0.0001). In addition, those with intramural VSDs had longer postoperative hospital length of stay compared with those with nonintramural VSDs or no residual VSD (20 days [interquartile range, 11-42 days] versus 7 days [interquartile range, 5-14 days] versus 6 days [interquartile range, 4-11 days]; P=0.0001). These associations remained significant after adjustment for known risk factors for poor outcomes, including residual VSD size and operative complexity.

CONCLUSIONS

Among residual VSDs after repair of conotruncal anomalies, intramural VSDs are uniquely associated with postoperative morbidity, mortality, and longer postoperative hospital length of stay. It is important to recognize intramural VSDs in the postoperative period.

Accuracy of the transpulmonary ultrasound dilution method for detection of small anatomic shunts

The purpose of this study was to investigate the qualitative and quantitative accuracy of transpulmonary ultrasound dilution (UD) (COstatus™, Transonic Systems) for the detection of small anatomic shunts. It was a prospective, observational study in a multi-disciplinary pediatric intensive care unit. Seventy-three critically ill children (67 post cardiac surgery), with a median (IQR) age of 10 (3-50.3) months and a median (IQR) weight of 8 (3.43-13) kg were enrolled. Ultrasound dilution (UD) measurements were performed on patients within 1 h of undergoing two-dimensional echocardiography, which was used as the comparator technique. Shunt was diagnosed by characteristic changes on the UD curve shape, and was considered "test-positive" only if two or more measurements suggested the presence of the shunt. The UD technology also provided an estimate of pulmonary to systemic blood flow ratio (Qp:Qs). 12/73 (16.4 %) patients had a shunt identified by both UD and echocardiography. The overall accuracy (95 % CI) was 86.1 % (75.6-96.6 %), with a sensitivity of 85.7 % (57.2-98.2 %) and specificity of 86.4 % (75.0-94.0 %). The estimated Qp:Qs ranged from 0.7 to 1.4, which was consistent qualitatively with the echocardiographic findings on color flow doppler. Shunt was detected by UD alone in eight children; six of these had clinical conditions known to compromise dilution curve analysis (valve regurgitation, asymmetric pulmonary blood flow). Shunt was detected by echocardiography alone in two children; in both cases the shunt was tiny. UD is an accurate method for the detection of small anatomical shunts, both qualitatively and quantitatively.

Minimally invasive perventricular device closure of ventricular septal defect in infants under transthoracic echocardiograhic guidance: feasibility and comparison with transesophageal echocardiography

BACKGROUND

A hybrid approach to minimally invasive perventricular closure of VSD in infants is safe and effective, and has been performed under guidance of transesophageal echocardiography (TEE). We applied transthoracic echocardiographic (TTE) guidance to this hybrid approach, and compare results guided by TTE with those by TEE.

METHODS

From January 2011 to January 2012, 71 infants with VSD were enrolled to undergo a minimally invasive device closure. After evaluation of VSD by TTE, either TEE or TTE was used to guide the minimally invasive device closure. 30 patients had TEE guidance, and 41 patients had TTE. All patients were followed for 3 months after the operation.

RESULTS

The TEE group had a success rate of 93.3% (28/30) for device implantation, compared with 92.7% (38/41) in the TTE group. Two patients in the TEE group turned to surgical closure, one for involvement of the inlet area of VSD demonstrated by TEE, another for moderate aortic regurgitation after device implantation. Two patients in the TTE group also transferred to surgical closure, one for residual shunt, another for failure of the floppy wire across the defect. In addition, one patient in the TTE group experienced dropout of the occluder one day postoperatively. At 3-month follow-up, one patient had mild aortic regurgitation in the TEE group and in two patients in the TTE group. There were no episodes of cardiac block, thromboembolism, or device displacement in either group.

CONCLUSIONS

TTE-guided VSD closure is feasible in infants, with results similar to those of TEE guidance, although caution is advisable.

Transesophageal Echocardiography in Tetralogy of Fallot

Transesophageal echocardiography (TEE) plays an important role in the anatomical, functional, and hemodynamic assessment of patients with congenital heart disease (CHD). This imaging approach has been applied to both children and adults with a wide range of cardiovascular malformations. Extensive clinical experience documents significant contributions, particularly in the perioperative setting. In fact, in the current medical era, many consider this technology to be an essential adjunct to surgical and anesthetic management in CHD. This review focuses on the applications of TEE in patients with tetralogy of Fallot (TOF), the most common form of cyanotic heart disease. Emphasis is given to the perioperative use of this imaging modality and benefits derived during the prebypass and postbypass periods. Limitations and pitfalls relevant to the TEE assessment in patients with this anomaly are also addressed.

Transthoracic echocardiographic guidance of minimally invasive perventricular device closure of perimembranous ventricular septal defect without cardiopulmonary bypass: initial experience

BACKGROUND

Our purpose was to investigate the feasibility of transthoracic echocardiographic (TTE) guidance for minimally invasive periventricular device closure of perimembranous ventricular septal defects (VSDs).

METHODS

From June 2011 to September 2011, we enrolled 18 young children with perimembranous VSDs to receive minimally invasive device closure in our hospital. All of the patients were examined by TTE to determine the VSD morphology, diameter, and rims. During intra-operative device closure, real-time bedside TTE alone was used to guide device implantation.

RESULTS

Device implantation using TTE guidance was successful in 16 patients. Symmetric devices were used in 14 patients, and asymmetric devices were used in 2 patients. Only one patient experienced mild aortic regurgitation, and there were no instances of residual shunt, significant arrhythmias, thromboembolism, or device displacement. Two patients were transferred to surgical closure, one due to residual shunting and the other as a result of unsuccessful wire penetration of the VSD gap.

CONCLUSIONS

Our data indicate that TTE-guided VSD closure is feasible in young children, although a longer follow-up may be needed to document the long-term success.

Treatment of isolated ventricular septal defects in children: Amplatzer versus surgical closure

BACKGROUND

Isolated hemodynamically significant ventricular septal defects (VSD) were previously treated surgically. Since the introduction of percutaneous (PC) devices, the management of isolated VSD has evolved. In our center, Amplatzer devices have been implanted for selected isolated perimembranous VSD since 2002.

METHODS

The charts of all isolated PC perimembranous VSD closures and all surgical closures performed since 2002 were reviewed retrospectively. Clinical, electrocardiographic, and echocardiographic data were analyzed. The preclosure, immediate postclosure, and 1-month, 6-month, and 12-month postclosure results were assessed.

RESULTS

Thirty-seven patients underwent PC closure, and 34 had surgical treatment. Mean follow-up was 42.1 ± 26.0 months. The PC group was significantly older (p < 0.01) and larger in size (p < 0.001). Surgical patients had more severe congestive heart failure and a significantly lower VSD gradient (p < 0.004). At follow-up, there were no differences in the incidence of residual shunting between the two groups (p = 0.92). All valvular regurgitations improved over time, except for 3 aortic regurgitations (5.4%) in the PC group that got worse. Two permanent pacemakers were implanted for early complete heart block in the PC group, and one was implanted in the surgical group (p = 0.94).

CONCLUSIONS

The surgical results in our population were excellent. The selection of patients with perimembranous VSD remains a challenge to avoid post-PC intervention complications such as heart block and aortic insufficiency. For isolated VSD, PC closure, which avoids the morbidity of open heart surgery, should be considered as part of the therapeutic armamentarium.

Predictive value of intraoperative diagnosis of residual ventricular septal defects by transesophageal echocardiography

BACKGROUND

Intraoperative transesophageal echocardiography (IOTEE) is well established as a monitoring tool during ventricular septal defect (VSD) repair to ensure complete closure of the defect. Residual shunts detected by IOTEE are common. The predictive value of IOTEE findings on the long-term course of residual shunts is not well documented, especially in regard to the need for reoperation or bacterial endocarditis prophylaxis. The objective of this study is to determine the predictive value of intraoperative IOTEE diagnosis of residual VSDs and therefore delineating the natural history of these findings.

METHODS

Retrospective review of IOTEE reports of 690 consecutive patients with VSD (isolated or part of a complex lesion) was undertaken. Those were compared with transthoracic echocardiographic reports of these patients before their discharge from the hospital, and the most recent transthoracic echocardiographic examination. Positive and negative predictive values, sensitivity, and specificity of such diagnoses were then calculated from predischarge and from follow-up transthoracic echocardiographic data.

RESULTS

There were 260 of 690 patients with a residual VSD on IOTEE; 24 required repeat cardiopulmonary bypass for complete closure. There were 573 patients with predischarge transthoracic echocardiographic examination; 296 had residual VSDs (125 not detected by IOTEE), and 13 defects required reoperation during the same hospitalization, 5 of which were detected by IOTEE. The positive and negative predictive values were 78% and 65%, respectively. Follow-up transthoracic echocardiographic examination of 383 local patients showed residual VSD in 57 (37 not detected by IOTEE), with positive and negative predictive values of 15% and 83%, respectively.

CONCLUSIONS

Although IOTEE is sensitive enough to detect residual VSD shunts in many patients (37% of this cohort), the majority of these defects are trivial and resolve spontaneously, with a positive predictive value of only 15% on follow-up transthoracic echocardiographic examination and a rare need for reoperation.

Can intraoperative TEE correctly measure residual shunt after surgical repair of ventricular septal defects?

PURPOSE

No groups have yet succeeded in identifying the need for re-repair of residual shunt after surgical repair of ventricular septal defect (VSD) based on quantitative evaluation of the ratio of the pulmonary blood flow to the systemic blood flow (Qp/Qs) by transesophageal echocardiography (TEE). Hence, we studied the accuracy of Qp/Qs as estimated by intraoperative TEE.

METHODS

Twenty-six patients undergoing VSD closure were studied. After separation from the cardiopulmonary bypass, the presence and severity of residual leakage was evaluated by color Doppler image, and the Qp/Qs (TEE-derived Qp/Qs) was calculated by measuring the vessel diameter and the velocity-time integral of the flow profiles in the main pulmonary artery and left ventricular outflow tract. Transthoracic echocardiography (TTE) was performed at pre-discharge and at 6-12 months after the correction to confirm the presence and severity of residual leakage.

RESULTS

TEE detected only minor leakage, with no indication for re-repair, in 8 of the 26 patients. Nevertheless, TEE-derived Qp/Qs varied from 0.57 to 2.07 and were incorrect in 17 patients (65.4%). This meant that when TEE-derived Qp/Qs was outside the acceptable range, the patient was judged not to be in need of re-repair. TTE at pre-discharge confirmed trivial leakage in 3 patients in whom TEE had also identified similar leakages. These leakages were not observed at the follow-up TTE.

CONCLUSION

TEE-derived Qp/Qs lacks the accuracy required to play a crucial role in quantitatively measuring the severity of residual shunt, while two-dimensional TEE can reliably detect residual leakage after VSD closure and lead to optimal judgment on the need for re-repair.

Catheters, wires, tubes and drains on postoperative radiographs of pediatric cardiac patients: the whys and wherefores

Surgical treatment of congenital heart disease has advanced dramatically since the first intracardiac repairs in the mid-20th century. Previously inoperable lesions have become the focus of routine surgery and patients are managed successfully in intensive care units around the world. As a result, increasing numbers of postoperative images are processed by departments of radiology in children's hospitals. It is important that the radiologist accurately documents and describes the catheters, wires, tubes and drains that are present on the chest radiograph. This article reviews the reasons for the placement and positioning of perioperative equipment in children who have surgical repair of atrial septal defect, ventricular septal defect or transposition of the great arteries. Also included are a brief synopsis of each cardiac anomaly, the surgical procedure for its correction, and an in-depth discussion of the postoperative chest radiograph including illustrations of catheters, wires, tubes and drains.

Severity scoring system for ventricular septal defect

INTRODUCTION

Residual ventricular septal defect (RVSD) occurs in one-third of patients undergoing patch closure of congenital VSD. Indications for re-intervention are often based on either patient's symptoms or echocardiographic or hemodynamic studies. We report a novel scoring system for RVSD that takes into account all of the above criteria.

METHODS

RVSD size, Qp:Qs ratio, RV to LV pressure ratio, and heart failure symptoms are scored as follows: (A) RVSD size is subdivided into three categories: <3 mm, 3 to <4 mm, and >/=4 mm; (B) Qp:Qs ratio is also subdivided into three categories: <1.5, 1.5 to <2, and >/=2.0; (C) The right and left ventricular pressure ratio is subdivided into the following: <0.5, 0.5 to <0.75, and >/=0.75; (D) Heart failure symptoms are subdivided into three categories: NYHA class II/III, NYHA class IV, and pulmonary edema requiring assisted ventilation. Each of these categories is given a score value of one (less severe), two (intermediate severity), and three (severe). Intra-operative severity score of RVSD is calculated by adding the total score of A, B, and C. For post-operative RVSD severity, the score values of A, B, C, and D are added. According to the total score, the clinical significance of an intra-operative RVSD is then defined as mild, moderate, or severe for a score of </=3, 4-5, and >/=6, respectively. Similarly, post-operative RVSD is then labeled as mild, moderate, or severe for a score of </=4, 5-7, and >/=8, respectively.

CONCLUSION

From our experience and review of literature, severe RVSD (and moderate VSD post Tetrology of Fallot (TOF) repair) require immediate closure of RVSD. Other patients with mild or moderate RVSD need close follow-up with a repeat of transesophageal echocardiography (TEE) before discharge, and six months after surgery. This scoring system, however, needs further prospective evaluation to assess its potential role in decision-making in the management of RVSD.

Spontaneous closure of small residual ventricular septal defects after surgical repair

BACKGROUND

Residual shunts may be detected by intraoperative or postoperative echocardiography after surgical closure of a ventricular septal defect (VSD). The hemodynamic relevance and rate of late closure are unknown.

METHODS

Between 1994 and 2005, 198 consecutive patients underwent surgical correction of an isolated VSD (n = 100), tetralogy of Fallot (n = 52) or atrioventricular septal defect (n = 46). Intraoperative transesophageal echocardiography (TEE) was routine, and postoperative transthoracic echocardiography was performed in the intensive care unit, at hospital discharge, and during follow-up. Residual defects were graded as absent, between 1 and 2 mm, or greater than 2 mm.

RESULTS

Shunt-related discrepancy was observed between intraoperative TEE and intensive care unit transthoracic echocardiographic findings; significantly so after Fallot repair (p < 0.0001). After discharge, 83% of all residual defects less than 2 mm closed. Of nine residual defects greater than 2 mm, only three closed after a median follow-up of 3.1 years. In patients with residual shunts, they were hemodynamically insignificant, required no medication, and no endocarditis was noted. At last follow-up, there was no significant difference between the percentage of residual shunts among the three groups (p = 0.135).

CONCLUSIONS

Postsurgical residual VSDs less than 2 mm closed spontaneously in the majority within a year. Defects greater than 2 mm are unlikely to close spontaneously. Residual shunts after atrioventricular septal defect repair almost always close, whereas one third will remain open after Fallot or isolated VSD repair. At midterm follow-up, residual shunts remained hemodynamically and clinically irrelevant. Revision of a residual defect greater than 2 mm on cardiopulmonary bypass at initial repair, guided by TEE, may spare late redo surgery and lifelong antibiotic prophylaxis.

Experience with intraoperative ultrasound in paediatric cardiac surgery

OBJECTIVE

Intraoperative ultrasound was introduced to evaluate the adequacy of repair after surgical repair of congenital cardiac malformations. Our purpose was to review the evolution of this technique at our centre.

METHODS

We evaluated all intraoperative ultrasound studies undertaken between 1997 and 2002, reviewing the data from 1997 through 2001 retrospectively, but undertaking a prospective audit of studies undertaken from 2002 onwards. In all, we carried out a total number of 639 intraoperative ultrasound studies, from a possible 2737 cardiac operations (23.3%), using the epicardial approach in 580 (90.7%), and transoesophageal ultrasound in the other 59 patients (9.3%). Median age was 0.6 years, with an interquartile range from 0.06 to 3.6 years.

RESULTS

The findings obtained using intraoperative ultrasound influenced the surgical management in 63 of the 639 patients (9.9%), suggesting the need for additional surgery in 26, adjustment of the band placed round the pulmonary trunk in 16, preoperative assessment of the cardiac malformation in 5, and confirming the need for prolonged support with cardiopulmonary bypass for impaired ventricular function in 16. There were 18 early reoperations, 5 of which may have been predicted by intraoperative ultrasound. Of the 183 studies reviewed prospectively in 2002, it was not possible to obtain the complete range of views in 8 (4.4%), while in 27 patients (14.7%), the postoperative findings using transthoracic interrogation differed from the findings obtained immediately following bypass.

CONCLUSION

Intraoperative ultrasound is an important technique for monitoring the results of complex congenital cardiac surgery. The immediate recognition of significant lesions, together with multidisciplinary discussion, allows for improved management and prevention of early surgical reintervention.

Percutaneous closure of postoperative ventricular septal defects with the amplatzer device

The objective of this study was to look at the procedure, the results, and the follow-up of patients who underwent percutaneous closure of a residual ventricular septal defect (VSD) following a surgical closure using the Amplatzer VSD device. Four patients had an original diagnosis of tetralogy of Fallot, two patients had a patch leak following a surgical repair of a VSD, and three patients had a VSD not repaired at the time of surgery. All patients fulfilled the currently accepted surgical criterion for reoperation (Qp/Qs>1.5). The mean Qp/Qs was 1.8+/-0.3 (1.5-2.3). Four patients underwent VSD closure using an Amplatzer perimembranous VSD device and in five patients an Amplatzer muscular VSD device was implanted. We performed percutaneous closure in nine patients. The size of the residual shunt ranged from 6 to 14 mm and the size of device used ranged from 8 to 16 mm. The arteriovenous loop needed to be recreated in two patients because of failure to advance the delivery sheath. There was complete closure of the defect in six cases, and a small residual shunt remained in three cases. Percutaneous closure of postoperative VSDs appears to be an effective way to resolve a hemodynamically significant residual shunt. There were no difficulties encountered with implantation of the devices. These promising short-term results need reinforcement with additional long-term data.