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David L S Morales

Publications and source records attributed to David L S Morales.

13 recordsLinked to original sources
PubMed2006

Heterotaxy patients with total anomalous pulmonary venous return: improving surgical results.

BACKGROUND: Survival after repair of total anomalous pulmonary venous return in patients with heterotaxy syndrome has consistently been reported in the literature to be far inferior to the results obtained in nonheterotaxy patients. The outcomes of heterotaxy patients at Texas Children's Hospital undergoing repair of total anomalous pulmonary venous return were examined and compared with those of nonheterotaxy patients. METHODS: Between July 7, 1995, and November 22, 2005, 122 consecutive patients underwent primary repair of total anomalous pulmonary venous return. Characteristics were as follows: mean age, 0.35 +/- 1.8 years; mean weight, 4.3 +/- 2.8 kg; single ventricle, 40 (33%); heterotaxy, 38 (31%); pulmonary atresia, 13 (11%). Concomitant procedures included pulmonary artery banding in 4 (3%), systemic-to-pulmonary shunt in 14 (12%), bidirectional Glenn in 11 (9%), and other in 16 (14%). RESULTS: With a mean follow-up of 2.6 +/- 2.5 years including all patients, overall 30-day and 5-year survival was 93% and 86%, respectively; for heterotaxy patients it was 84% and 79%; and for nonheterotaxy patients it was 96% and 89%. Heterotaxy and nonheterotaxy survival curves were not significantly different (p> 0.05). Overall, there were 12 (9.8%) patients who required reoperation for pulmonary vein stenosis, at a mean of 5.1 +/- 5.5 months postoperatively. Seven (58%) reoperations were in heterotaxy patients. Rate of pulmonary vein reoperation is statistically greater (p < 0.05) for heterotaxy patients than nonheterotaxy patients. At last follow-up, all patients were in New York Heart Association class II or less. Using Cox proportional hazards models, pulmonary atresia and need for systemic-to-pulmonary shunt were risk factors for death (not heterotaxy). Single ventricle, operation after July 2000, and need for systemic-to-pulmonary shunt were risk factors for pulmonary vein reoperation. CONCLUSIONS: At midterm follow-up, heterotaxy patients undergoing total anomalous pulmonary venous return repair have a higher pulmonary vein reoperative rate but a comparable overall survival to nonheterotaxy patients.

Adolescent↗
PubMed2006

Interrupted aortic arch repair: aortic arch advancement without a patch minimizes arch reinterventions.

BACKGROUND: Surgical repair of interrupted aortic arch (IAA) remains challenging and is associated with significant mortality and incidence of late arch obstruction, as recently reported by the Congenital Heart Surgeons' Society (CHSS). In particular, the CHSS reported that any technique other than direct anastomosis with patch augmentation is a risk factor for arch reintervention. The experience at Texas Children's Hospital with IAA repair using an aortic arch advancement technique without a patch was examined. METHODS: Between July 1995 and December 2005, 60 patients underwent IAA repair using aortic arch advancement without a patch. Selective cerebral perfusion was used in 25 patients (42%). Cox proportional hazards models were used to analyze 20 variables to determine risk factors for death, arch reintervention, and left ventricular outflow tract (LVOT) reintervention. RESULTS: Median age was 8 days (range, 2 to 271 days) and weight was 3.0 kg (range, 1.7 to 6.1 kg). IAA types were A in 18 (30%) and B in 42 (70%). Associated anomalies were multiple congenital anomalies in 30 (50%) patients, DiGeorge syndrome in 21 (35%), LVOT obstruction in 26 (43%), a single ventricle in 11 (18%), and truncus arteriosus in 6 (10%). Mean follow-up was 3.0 +/- 2.6 years. Five-year freedom from aortic arch reintervention was 100%. Survival at 30 days, 1 year, and 5 years was 93%, 78%, and 76%, respectively. Since July 2000, two of 32 patients have died for an overall survival of 94%. Risk factors for death are older age, multiple congenital anomalies, DiGeorge syndrome, and bicuspid aortic valve. Selective cerebral perfusion was an independent protective variable for survival. Survival for an IAA patient with a ventricular septal defect and no complicating cardiac anomalies was 100%. CONCLUSIONS: Aortic arch advancement without a patch can be applied to IAA patients, with the expectation of a minimal need for arch reintervention. This technique affords an excellent survival, to which selective cerebral perfusion may be a contributing factor.

Abnormalities, Multiple↗
PubMed2006

An alternative treatment strategy for pump thrombus in the DeBakey VAD Child: use of clopidogrel as a thrombolytic agent.

Our institution has used the DeBakey VAD Child as a bridge to heart transplantation in select pediatric patients. Pump thrombus is a potentially serious complication with few available treatment options. Only surgical device exchange or the use of tissue plasminogen activator are reported in the literature. We report the use of clopidogrel as an alternative thrombolytic agent in the presence of pump thrombus in an adolescent patient with a DeBakey VAD Child heart pump.

Adolescent↗
PubMed2006

Encouraging results for the Contegra conduit in the problematic right ventricle-to-pulmonary artery connection.

OBJECTIVE: The Contegra conduit was developed for right ventricular outflow tract reconstruction. This report evaluates the Contegra conduit, with focus on certain subpopulations in which conduits are known to perform poorly (ie, patients with previous homograft conduits and infants). METHODS: A retrospective review of 76 patients who had 77 Contegra conduits placed for right ventricular outflow tract reconstruction (January 2001 through August 2005) was completed. Characteristics include the following: median age of 1.6 years (range, 17 days-15.1 years), weight of 9.8 kg (range, 2.5-64.0 kg), and conduit diameter of 16 mm (range, 12-22 mm). Operations performed include right ventricular outflow tract reconstruction for pulmonary atresia-stenosis (n = 33), conduit exchange (n = 28), truncus repair (n = 7), primary conduit placement (n = 6), and the Ross procedure (n = 3). Seventy-nine percent were reoperations. RESULTS: There was no hospital mortality. Mean follow-up was 20 +/- 14 months. One-, 2-, and 3- year freedom from severe conduit regurgitation was 97%, 86%, and 81%, respectively, and freedom from severe conduit stenosis was 100%. Freedom from reoperation for conduit failure at 1 and 3 years is 98.3% and 93.1%, respectively. All conduit failures (n = 3) were for asymptomatic conduit pseudoaneurysms in the setting of multiple-level pulmonary branch stenoses. Survival at 3 years is 96%. Infants (n = 26) had a freedom from Contegra conduit failure at 3 years of 100%. Patients with previous homograft conduits (n = 26) had a freedom from Contegra conduit failure at 3 years of 100%. CONCLUSION: At midterm follow-up, the Contegra conduit remains a reliable, accessible, and easily implantable conduit for right ventricular outflow tract reconstruction. It appears to be the most promising conduit option for patients with previous homograft conduits and for infants.

Abnormalities, Multiple↗
PubMed2006

Preliminary experience with the MicroMed DeBakey pediatric ventricular assist device.

Mechanical circulatory support for both acute and chronic heart failure is a widely applied therapeutic option in the adult population with a variety of devices clinically available. Technology in this field has advanced sufficiently such that long-term support or "destination therapy" has become a generally accepted reality. Similar progress has not occurred in the field of device support for heart failure in children. While the number of potential patients is significantly lower in the pediatric population, the clinical relevance and poignancy of individual need are nonetheless real. Until recently, children with heart failure have been largely disadvantaged in comparison to their adult counterparts. The DeBakey VAD Child (MicroMed Technology, Inc, Houston, TX) represents a hopeful initial step in the direction of reducing the technological gap between adults and children. While the clinical experience with this device is limited at present, preliminary results are encouraging. This report will provide an overview of the DeBakey VAD Child, including device specifications, indications for clinical use, surgical and postoperative considerations, and updated clinical experience.

Adolescent↗
PubMed2005

Aortic atresia and type B interrupted aortic arch: diagnosis by physiologic cerebral monitoring.

Physiologic cerebral monitoring has become an important part of our cardiovascular surgical unit. We recently encountered an unusual variant of aortic atresia that was first suggested by physiologic cerebral monitoring and required modification of our operative technique. We describe and discuss the anatomy, its translation into cerebral monitor findings, and how we modified our operative technique.

Aorta, Thoracic↗
PubMed2005

Salvaging the failing Fontan: lateral tunnel versus extracardiac conduit.

BACKGROUND: Since Fontan revision has been demonstrated to provide hemodynamic and symptomatic improvement in select patients with failing Fontan circulations, we now believe it is important to determine if one type of revision (lateral tunnel [LT] or extracardiac conduit [ECC]) provides superior outcomes. METHODS: Thirty-five Fontan revisions were performed (Jun 1997 to Dec 2004): 19 ECC (54%) and 16 LT. Preoperative variables were similar: New York Heart Association (NYHA) IV (LT = 4 vs ECC = 2, p = not significant [NS]), preoperative arrhythmias (LT = 13 vs ECC = 16, p = NS) and systemic right ventricle (LT = 4 vs ECC = 2, p = NS). Twenty-eight patients (80%) underwent a modified maze procedure (LT = 12 vs ECC = 16, p = NS) and 29 (83%) had pacemaker placement (LT = 11 vs ECC = 18, p < 0.05). RESULTS: There were no hospital deaths and no arrhythmias at hospital discharge. There were no differences in mean duration of intubation (LT 0.6 vs ECC 0.9 days, p = NS), inotropic support (LT 1.5 vs ECC 2.1 days, p = NS), intensive care unit stay (LT 2.6 vs ECC 3.5 days, p = NS), hospital stay (LT 8.8 vs ECC 9.7 days, p = NS), or episodes of acute postoperative arrhythmias (LT = 2 vs ECC = 4, p = NS). On intermediate follow-up (29 +/- 22 months), the overall cohort had 94% survival, 97% of survivors in NYHA class I/II, 91% freedom from late arrhythmias requiring medication, and no patient required cardiac transplantation. Follow-up revealed no differences in NYHA I/II (LT = 14 vs ECC = 18, p = NS), mortality (LT = 2 vs ECC = 0, p = NS), or late arrhythmia (LT = 4 vs ECC = 4, p = NS). CONCLUSIONS: Both the LT and ECC revisions provide symptomatic benefit for a failing Fontan connection and have equivalent early and intermediate results including arrhythmia recurrence.

Adolescent↗
PubMed2005

Lessons learned from the first application of the DeBakey VAD Child: an intracorporeal ventricular assist device for children.

We report and describe the design and the first clinical implantation of the DeBakey ventricular assist device (VAD) Child, a pediatric intracorporeal left ventricular assist device, in a 6-year-old girl. The risk-benefit of novel technologies in advanced heart failure and the lessons learned by our experience are important to consider in hopes that other centers (where this device is now available) may benefit.

Cardiomyopathies↗
PubMed2003

A double-blind randomized trial: prophylactic vasopressin reduces hypotension after cardiopulmonary bypass.

BACKGROUND: Inhibition of angiotensin-converting enzyme (ACE) predisposes patients to vasodilatory hypotension after cardiopulmonary bypass (CPB). This hypotension has been correlated with arginine vasopressin deficiency and can be corrected by its replacement. In patients receiving ACE inhibition, we investigated whether initiation of vasopressin before CPB would diminish post-CPB hypotension and catecholamine use by avoiding vasopressin deficiency. METHODS: Cardiac surgical patients on ACE inhibitor therapy were randomized to receive vasopressin (0.03 U/min) (n = 13) or an equal volume of normal saline (n = 14) starting 20 minutes before CPB. RESULTS: Vasopressin did not change pre-CPB mean arterial pressure or pulmonary artery pressure. After CPB, the vasopressin group had a lower peak norepinephrine dose than the placebo group (4.6 +/- 2.5 versus 7.3 +/- 3.5 microg/min, p = 0.03), a shorter period on catecholamines (5 +/- 6 versus 11 +/- 7 hours, p = 0.03), fewer hypotensive episodes (1 +/- 1 versus 4 +/- 2, p < 0.01), and a shorter intensive care unit length of stay (1.2 +/- 0.4 versus 2.1 +/- 1.4 days, p = 0.03). CONCLUSIONS: In this cohort, prophylactic administration of vasopressin, at a dose without a vasopressor effect pre-CPB, reduced post-CPB hypotension and vasoconstrictor requirements, and was associated with a shorter intensive care unit stay.

Adult↗
PubMed2003

Advanced thoracoscopic procedures are facilitated by computer-aided robotic technology.

OBJECTIVE: Computer (robotic) enhancement has been used to facilitate simple thoracoscopic procedures such as internal mammary artery (IMA) mobilization. This report describes the use of robotic technology in advanced thoracoscopic procedures. METHODS: Ten patients underwent advanced thoracoscopic procedures utilizing the Da Vinci robotic surgical system (Intuitive Surgical, Mountain View, CA) at our institution. RESULTS: Patients 1-6 underwent endoscopic phrenic nerve mobilization with insertion of phrenic nerve pacemakers. The indications were quadriplegia (n=2), central hypoventilation syndrome (n=2), and intractable hiccups (n=2). Three 1-cm incisions were made to access each hemithorax. Patients 7 and 8 underwent robotically assisted resection of posterior mediastinal masses. Patient 9 underwent robotically assisted thoracoscopic left lower lobectomy for a lung mass. Patient 10 underwent robotically assisted left ventricular lead placement for biventricular pacing for heart failure. CONCLUSIONS: Robotic technology can be used to perform advanced intrathoracic maneuvers thoracoscopically. The increased visualization and instrument dexterity afforded by this technology may facilitate the development of minimally invasive thoracic approaches that were previously not feasible.

Adolescent↗
PubMed2002

Restoration of renal function in shock by perfusion of the renal artery with venous blood: a counterintuitive approach.

OBJECTIVE: Acute renal failure (ARF) in low-flow states may be reversed by increasing renal perfusion. When hemodynamics are maximized, renal perfusion can only be improved by shunting a higher proportion of cardiac output to the kidney; however, in low-flow states, this reduces already compromised systemic pressure and perfusion to other organs. Increasing perfusion using venous blood (VB) would be an attractive option because decreased systemic pressure and perfusion to other organs could be avoided. However, it is not known whether VB can provide adequate oxygen delivery to restore or maintain renal function. We studied whether antegrade VB perfusion of the kidney via the renal artery would restore urine output (UO) and glomerular filtration rate (GFR) in hypoperfused ARF. DESIGN: Shock was induced in six dogs via a hemorrhagic protocol resulting in a systolic blood pressure of 50-70 mm Hg, a mixed venous oxygen saturation of 25% to 40%, and a UO <10% of baseline. After 60 mins of shock, the left renal artery was cannulated under fluoroscopy and perfused at pressures of 100-150 mm Hg for 30 mins with VB drawn from the vena cava and delivered by an extracorporeal pump system. The right kidneys were controls and remained hypoperfused. RESULTS: All VB-perfused kidneys recovered renal function after a sustained period of shock and marked oliguria: UO from 0.7 +/- 1.6 mL/hr to 101 +/- 58 mL/hr (p <.01); GFR from approximately 0 to 70.3 +/- 55 mL/min (p =.04). The control kidneys' UO (0.7 +/- 1.6 mL/hr) and GFR (0 mL/min) remained unchanged throughout the study. The experimental kidneys were able to extract oxygen from VB (O2 saturation, 31 +/- 7% to 16 +/- 4%; p =.01). CONCLUSION: When flow is controlled, kidneys in hypoperfused ARF can extract sufficient oxygen from antegrade VB perfusion to restore renal function (UO and GFR).

Acute Kidney Injury↗
PubMedDate not supplied

Hurricane Katrina: emergent interstate transport of an evacuee on biventricular assist device support.

In many U.S. hospitals, mechanical circulatory support has become routine. However, catastrophes such as Hurricane Katrina test the abilities of a hospital system to sustain patients on such support and transport them in emergent situations. A 15-year-old boy with dilated cardiomyopathy who was receiving biventricular mechanical circulatory support at a New Orleans hospital was successfully transported by Angel One Transport from Arkansas Children's Hospital across state lines to Texas Children's Hospital, where he was stabilized and received an orthotopic heart transplant.

Adolescent↗