William I. Douglas

Hemi-Fontan procedure for hypoplastic left heart syndrome: outcome and suitability for Fontan

BACKGROUND Following the Norwood procedure for hypoplastic left heart syndrome (HLHS), pulmonary artery distortion and hypoplasia are common and may negatively impact late outcome. The hemi-Fontan procedure (HFP) augments the central pulmonary arteries and establishes a connection between the right atrial/superior vena cava junction and the pulmonary arteries, while excluding the inferior vena cava. METHODS The hospital records of all 114 patients undergoing a HFP for HLHS between August 1993 and April 1998 were reviewed to assess patient, procedural, and morphologic determinations of outcome. The results of cardiac catheterization, Doppler/echocardiography, 12 lead electrocardiograms, hospital and subsequent course, as well as suitability and outcome for the Fontan procedure were analyzed. RESULTS Mean age was 5.4 months (range 1.5 to 15 months). Right ventricular function was normal in 95 patients, moderately depressed in 14, and severely depressed in five. Tricuspid regurgitation was absent or mild in 91 patients, moderate in 13, and severe in 10. Concomitant procedures included left superior vena cava to pulmonary artery anastomosis (12), tricuspid valve repair (10), pulmonary artery stent placement (3), coarctation repair (2), and aortic pseudoaneurysm repair (1). Hospital survival was 112/114, 98% (95% confidence interval [CI]: 95% to 100%). There were two late deaths, one noncardiac. Sinus rhythm is present in 105 patients (92%, 95% CI: 87% to 97%). To date, 79 of these patients have undergone the Fontan procedure with 74 survivors (94%, 95% CI: 89% to 99%). CONCLUSIONS The HFP may be performed with excellent results for HLHS. It effectively augments the central pulmonary arteries while preserving sinus rhythm in the majority. In addition, the HFP facilitates the subsequent Fontan procedure and has significantly improved the overall outcome.

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.

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.

Anesthetic Implications of the Fontan Procedure for Single Ventricle Physiology

The Fontan procedure is the operation of choice for patients considered to be candidates for definitive palliation of single ventricle physiology. Anesthetic technique for the Fontan procedure is not well described in the literature, and the medical and surgical treatment of these patients is rapidly evolving. With an understanding of the anatomy and phys iology of the Fontan patient, a safe and effective anesthetic can be executed. An understanding of the changes that occur during the perioperative period is critical. This article focuses on a review of single ventricle physiology and Fon tan physiology, preoperative assessment and risk factors for the Fontan procedure, intraoperative management, and management of low cardiac output in the postbypass period.

Removal of an infected ventricular septal defect patch after tetralogy repair

An infected Dacron ventricular septal defect (VSD) patch was removed 15 years after repair of tetralogy of Fallot. Cardiopulmonary bypass was not utilized, and no significant hemorrhage was encountered. The patient recovered uneventfully and continues to do well 7 years after surgery without infection or residual VSD.

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.

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.

Arteriovenous malformation of the esophagus disguised as a leiomyoma

Hemangiomas, benign tumors of vascular origin, compromise less than 3% of all nonmalignant esophageal neoplasms. Because of their infrequent occurrence, such vascular tumors may be mistaken for more common benign tumors of the esophagus. We report the successful surgical management of an esophageal arteriovenous malformation presenting with clinical, radiographic, and endoscopic features resembling those of a leiomyoma.

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.