Unusual presentation of unroofed coronary sinus with cyanosis after ventricular septal defect closure.

Cyanosis after surgical closure of ventricular and/or atrial septal defect is very unusual. We report a case of unroofed coronary sinus in a six-month-old boy who developed cyanosis after surgical closure of ventricular and atrial septal defects. Clinical presentation, diagnosis, and management are discussed.

A Novel Technique for Repair of Complete Atrioventricular Canal Defect: The Central Patch Technique.

BACKGROUND: Two-patch, single-patch, and modified single-patch repairs are accepted techniques for repair of complete atrioventricular (AV) canal defects. We propose a novel, alternative technique: the central patch technique. METHODS: For the central patch technique, the superior and inferior bridging leaflets are attached with simple sutures to the right and left of their coaptation point. Both bridging leaflets are incised along a line above the ventricular crest, similar to a traditional single-patch technique. An oval pericardial patch is sewn to the central defect created in the AV valve tissue. Interrupted, horizontal mattress sutures are placed along the ventricular crest, through the midline of the central patch and through the edge of the atrial septal defect (ASD) patch. Tying the sutures simultaneously closes the ventricular septal defect (VSD) and secures the ASD patch to the ventricular crest. Repair of the left AV valve and ASD closure are performed in the routine fashion. RESULTS: Five patients underwent the central patch technique repair of complete AV canal defect. Weight was 4.8 to 6.3 kg; age was four to eight months. Cardiopulmonary bypass and myocardial times averaged 137 minutes and 109 minutes, respectively. No patient had more than mild left AV valve regurgitation or trivial residual VSD at completion of repair. No patient developed left ventricular outflow tract obstruction. CONCLUSION: The central patch technique is applicable to all forms of complete AV canal defect. Subjectively, it offers technical advantages compared to standard techniques and may result in a shorter learning curve for junior congenital heart surgeons. Results are preliminary but are consistent with standard techniques.

Investigational lymphatic imaging at the bedside in a pediatric postoperative chylothorax patient.

Chylothorax is a rare but serious complication in children who undergo heart surgery. Its pathogenesis is poorly understood, and invasive surgical treatments are considered only after conservative management fails. Current diagnostic imaging techniques, which could aid decision making for earlier surgical intervention, are difficult to apply. Herein, we deployed near-infrared fluorescence (NIRF) lymphatic imaging to allow the visualization of abnormal lymphatic drainage in an infant with postoperative chylothorax to guide the choice of surgical management. A 5-week-old male infant, who developed chylothoraces after undergoing Norwood surgery for hypoplastic left heart syndrome, was intradermally administered trace doses of indocyanine green in both feet and the left hand. NIRF imaging was then performed at the bedside to visualize lymphatic drainage patterns. Imaging results indicated impeded lymphatic drainage from the feet toward the trunk with no fluorescence in the chest indicating no leakage of peripheral lymph at the thoracic duct. Instead, lymph drainage occurred from the axilla directly into the pleural cavity. As a result of imaging, left pleurodesis was performed to stop the pleural effusion with the result of temporary decrease of left chest tube drainage. Although additional studies are required to understand normal and abnormal lymphatic drainage patterns in infants, we showed the potential of using NIRF lymphatic imaging at the bedside to visualize the lymphatic drainage pathway to guide therapy. Timely management of chylothorax may be improved by using NIRF imaging to understand lymphatic drainage pathways.

Neonatal coarctation repair with a long isthmus: the isthmus patch.

This case report illustrates a ductal-dependent coarctation repair in a neonate whose long isthmus was believed to make conventional end-to-end repair problematic. The isthmus and left subclavian artery were isolated and augmented with a homograft while flow to the descending aorta was preserved through the ductus. After patch augmentation of the isthmus, ductal tissue was resected and an end-to-end anastomosis was performed using the length of the augmented isthmus. Angiography 18 months later showed excellent growth of the arch despite homograft tissue comprising the majority of the isthmus at the time of repair.

Two-day control of pulmonary blood flow with an adjustable systemic-pulmonary artery shunt.

Our laboratory has developed an adjustable systemic-pulmonary artery shunt (AS) to provide improved control of pulmonary blood flow (PBF) after neonatal palliation of hypoplastic left heart syndrome (HLHS). Six piglets of 6-10 kg underwent left thoracotomy and placement of a 3.5 mm polytetrafluoroethylene (PTFE) shunt from the left subclavian artery to the left pulmonary artery (LPA). The LPA was ligated at its origin. An AS was placed on the PTFE graft after both anastomoses had been performed. A flow probe was placed on the LPA distal to the shunt insertion. The AS was adjusted every 2 hours (0.1 mm increments over 18 minutes) from fully open to an estimated 60% flow reduction throughout the 44-hour test period, similar to delayed sternal closure (DSC). At any shunt setting, standard deviations of normalized blood flow in each piglet were ranged from 1.34% to 8.05% indicating consistent and stable relationship between shunt setting and flow over the DSC. These data lend strong evidence that the device would perform successfully in a human infant during the DSC. Clinical trials are necessary to determine whether mechanical control of PBF results in improved clinical outcomes.

Cor triatriatum sinister with dilated coronary sinus from persistent left superior vena cava: a novel operative approach.

Persistent left superior vena cava is known to be associated with cor triatriatum. The persistent left superior vena cava drains into a dilated coronary sinus and can cause left atrial outflow obstruction by impinging on the posterior wall of the left atrium. Residual obstruction can persist, even after surgical resection of the cor triatriatum membrane. We describe a novel surgical treatment in a patient with cor triatriatum and persistent left superior vena cava.

The adjustable systemic-pulmonary artery shunt provides precise control of flow in vivo.

The ratio of pulmonary:systemic blood flow (Qp:Qs) remains problematic after single ventricle reconstruction. The adjustable systemic-pulmonary artery shunt (AS) was created as a solution for this problem. Prototype ASs were created using a screw-plunger mechanism as a variable resistor. A stepper motor controls plunger displacement. Six adult dogs underwent placement of a 4-mm AS in the femoral position to test its ability to control flow. Shunts were placed as arteriovenous fistulae to simulate the continuous flow of systemic-pulmonary AS. The 3.5-mm control shunts (CS) were placed on the contralateral side. The stepper motor was rotated from fully open to 3.4 mm of plunger depression for six complete cycles. Flow in the fully open AS was 687.9 +/- 28.7 cc/min* vs. 578.7 +/- 26.8 cc/min in the CS (flow +/- standard error, *p < 0.005 vs. CS). Standard deviation of flow was similar between the AS and CS, implying hysteresis in resistor function did not contribute to flow variability. Peak torque requirement to turn the resistor was 2.4 mNm. The AS offers excellent control of flow in vivo. Control of Qp:Qs may lead to improved outcomes for single ventricle reconstructions.

The use of stereolithographic hand held models for evaluation of congenital anomalies of the great arteries.

Imaging anomalies of the great vessels has traditionally been accomplished using conventional biplane modalities as well as three-dimensional (3D) video displays. Our aim was to review the use of stereolithography to create 3D models to assess coarctation of the aorta and vascular rings. Twelve patients had high-resolution CT scans to evaluate anomalies of the great arteries (coarctation: 9, vascular ring: 3). Ages were 19 days to 29 years and weights were 3.3 to 139 kg. Digital dicom data from each scan were converted by a commercially available software package into a 3D digital image. The area of interest was selected and the image was exported to a 3D stereolithographic printer to create a 3D model. The models were then evaluated and the results compared to catheterization and surgical findings. All models accurately displayed the pathology investigated. All 3 of the vascular ring models correlated with surgical findings (double arch: 2, pulmonary sling: 1). Models of aortic coarctation allowed clear depictions of discrete narrowing as well as arch hypoplasia and tortuosity. Stereolithography can create realistic 3D models that accurately display aortic pathology and add important additional information, which may have implications regarding surgical and transcatheter interventions and may also be useful teaching tools for parents and students.

Hypotension following cardiac surgery associated with paroxetine and mirtazapine withdrawal.

This case describes a 15-year-old patient who experienced postoperative hypotension following an elective Ross procedure for aortic stenosis/insufficiency. The patient was taking paroxetine and mirtazapine for depression which were held prior to surgery. Hypotension occurred approximately eight hours postoperatively and required vasopressor support. Upon reinitiation of antidepressant therapy, hypotension resolved and vasopressor support was discontinued. A year later the patient required conduit replacement, and antidepressant therapy was weaned off during the three weeks prior to surgery. No hypotension was observed following the second surgery. Paroxetine withdrawal has been well-documented within adult literature, but there is little information regarding mirtazapine withdrawal. Furthermore, cardiovascular effects have not been well-documented, and even less is known within the pediatric population. Withdrawal symptoms in these agents may be explained by cholinergic rebound and/or rapid decline in serum concentrations upon abrupt discontinuation. It may be reasonable to consider tapering antidepressants with short half-lives prior to elective surgery in which patients may not be able to take maintenance medications for more than 24 hours.

Left coronary artery arteriovenous malformation presenting as a diastolic murmur with exercise intolerance in a child with a suspected familial vascular malformation syndrome.

OBJECTIVE: Intracardiac arteriovenous malformations are rare and may be associated with sudden death in adults. This case report describes an intracardiac left coronary arteriovenous malformation in a 7-year-old boy with a suspected familial cutaneous vascular malformation syndrome. The patient presented with a diastolic murmur, exercise intolerance, chest pain, and a left ventricular mass. METHODS: The left ventricular mass was initially identified by echocardiography. Subsequently, a computed tomography scan revealed the vascular nature of the lesion. We hypothesized that the lesion represented either an arteriovenous malformation (AVM) or a hemangioma. These lesions are thought to cause coronary steal and myocardial dysfunction. Skin biopsies of the patient's cutaneous lesions revealed capillary hyperplasia, which was not consistent with either hemangioma or AVM. Thus, a surgical biopsy and partial resection of the mass was performed. RESULTS: The surgical pathology of the cardiac mass was consistent with an AVM. Within 6 months following partial resection of the mass, the patient unexpectedly developed a left ventricular pseudoaneurysm at the resection site and required re-operation. Although a portion of the mass remains, both the patient's chest pain and exercise tolerance have improved subjectively. CONCLUSION: Patients with cutaneous vascular malformations and diastolic murmurs, as well as cardiac symptoms, should undergo echocardiography or alternative imaging modalities to screen for treatable pathological myocardial vascular malformations.

Successful management of acute failure of the systemic right ventricle with cardiac resynchronization therapy.

Management of systemic right ventricular (RV) failure can be challenging. Anatomical abnormality due to congenital heart disease adds to the complexity when interventions are performed. We report a patient with acute systemic RV failure who was successfully managed with cardiac resynchronization therapy.

Postoperative fluid balance influences the need for antihypertensive therapy following coarctation repair.

OBJECTIVE: The purpose of the investigation was to determine the effect of fluid management on the need for perioperative antihypertensive therapy following coarctation repair. DESIGN: Retrospective case study. SETTING: Pediatric intensive care unit. PATIENTS: Infants and children with repaired coarctation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Hypertension was defined as a systolic blood pressure exceeding the 95th percentile for age. Echocardiographic variables included pre- and postoperative coarctation gradients, shortening fraction, left ventricular wall stress, and velocity of circumferential shortening. Clinical variables included age, fluid input, urine output (0-72 hrs), estimated creatinine clearance, intensive care unit stay, and diuretic use. Twenty-four patients were identified and divided into two groups. Group 1 consisted of six normotensive patients (19%, 1 wk to 2 yrs) and group 2 included 18 patients (75%, 3 wks to 12 yrs) with hypertension who required antihypertensive therapy. Group 2 patients were older (37 months vs. 3 months), received more intraoperative fluid, had lower urine output with fewer patients receiving diuretics, had diuretic therapy started later, and had longer intensive care unit stays (p < .05). When compared with group 2, 83% of group 2 patients had a net positive fluid balance between 36 and 72 hrs postoperatively. There were no differences in mean pre-/postoperative coarctation gradients, systolic function, postoperative fluids, estimated creatinine clearance, or aortic cross-clamp time. Using logistic regression analysis, we found that variables independently associated with the need for antihypertensive therapy included intraoperative fluid volume, 48- to 72-hr urine output, a positive fluid balance, and the use and timing diuretic therapy (p < .05). Subgroup analysis of infants <1 yr of age revealed similar findings. CONCLUSION: A net positive fluid balance caused by either the volume of intraoperative crystalloid infusion or a lower urine output contributes to the development of paradoxic hypertension following coarctation repair regardless of patient age. Limiting intraoperative fluids and early diuretic use may limit the need for antihypertensive therapy and shorten the intensive care unit stay.

Coarctation of the aorta.

Controversy still exists in the literature regarding definitive therapy for repair of coarctation of the aorta. Major factors involve not only the timing of repair, but also the method of repair, whether surgical or by percutaneous transluminal balloon dilatation. Results and complications of coarctation repair using various methods of classification present a diversity of results. This report will focus on these issues and attempt to dispel the statement that either one method or the other is the "choice method" of repair for any and all types of coarctation. Also presented is a proposed classification we believe will assist in clarifying the choice of therapy and perhaps improve not only the reporting of results, but also the results themselves. Methods of repair are discussed to provide the surgeon with a complete armamentarium of operations that the surgeon would tailor to the individual anatomicopathological patterns of the patient who presents at the time of surgery. Copyright 2000 by W.B. Saunders Company