Balancing pulmonary blood flow: Theory, in vitro measurements, and clinical correlation of systemic-to-pulmonary shunt banding.

BACKGROUND: Size mismatch between body and a systemic-to-pulmonary shunt can result in excessive pulmonary blood flow, compromising systemic oxygen delivery. Previously reported techniques to mechanically restrict shunt flow lack precision and reproducibility. We developed a formula for shunt banding and assessed its efficacy and reproducibility by in vitro and clinical measurements. METHODS: Formulas to determine diameter reduction, length of banding, and effect on the ratio of pulmonary blood flow (Qp) to systemic blood flow (Qs) were established. In vitro measurements of different shunt grafts were performed. Results were compared with calculations and clinical data. Clinical outcome was retrospectively assessed in all patients (n = 8) who underwent a shunt banding procedure at our institution between 2008 and 2012. RESULTS: Our formulas can adequately predict the length of the band based on the desired diameter and shunt type or on the Qp:Qs mismatch. In vitro measurements correlated with the manufacturer's specifications in small shunts (≤5 mm diameter; 0.45 mm mean wall thickness). The calculated diameters of these shunts were closely correlated with in vitro measurements (r = 0.953; P = .001). Arterial saturation, pH, and calculated Qp:Qs decreased significantly with banding (P = .026, .002, and .004, respectively). Clinical effects varied among patients, with hemodynamically stable patients achieving the most benefit. Adjustment of the band was required in 1 patient. No shunt thrombosis or shunt banding-related complications were noted. CONCLUSIONS: Our formulas and surgical strategy offer a new approach to controlling excessive pulmonary blood flow in shunt-dependent circulations in an effective and predictable way. The best reproducibility was achieved in small, thin-walled shunts. This strategy was most effective in patients with pulmonary overcirculation without hemodynamic decompensation.

Bilateral Retinal Detachments Caused by Severe Preeclampsia Diagnosed with Point-of-Care Ultrasound.

Bilateral retinal detachments are a rare complication of preeclampsia. We present a case report of a patient with an unknown pregnancy who presented with acute bilateral vision loss and elevated blood pressure. Point-of-care ocular ultrasound revealed bilateral retinal detachments. She was diagnosed with severe preeclampsia and taken for an urgent caesarean section with the delivery of a 26-week-old infant.

Longevity and durability of atrioventricular valve repair in single-ventricle patients.

BACKGROUND: The durability of atrioventricular valve (AVV) repair and risk factors for recurrent AVV regurgitation (AVVR) and reintervention in single-ventricle patients are not well defined. METHODS: Among 66 single-ventricle patients who underwent AVV repair between 1998 and 2011, 58 hospital survivors (88%) were retrospectively reviewed. Freedom from recurrent AVVR and reintervention were analyzed with Kaplan-Meier analysis. Predictors for recurrent AVVR, ventricular dysfunction, and reintervention were analyzed using regression analysis. RESULTS: Significant (more than mild+) AVVR developed in 47 patients (81%) during mean follow-up of 37 months (range, 0.2 to 103 months). Freedom from significant AVVR was 23.8% at 1 year and 16.9% at 5 years. Reintervention was performed in 12 patients (26%) at a mean of 24 months (range, 2 to 64 months) after the initial repair. Freedom from reintervention was 92.3% at 1 year and 75.3% at 5 years. There were 11 late deaths (19%). Predictors for recurrent AVVR included repair at stage II (p=0.020) and cardiopulmonary bypass time (p=0.014). Predictors for reintervention included valvuloplasty as a repair technique (p=0.013), cardiopulmonary bypass time (p=0.002), aortic cross-clamp time (p=0.003), and significant residual intraoperative AVVR (p=0.012). Intraoperative ventricular dysfunction (p<0.001), aortic cross-clamp time (p=0.005), and cleft as the mechanism of regurgitation (p=0.023) predicted postrepair ventricular dysfunction. CONCLUSIONS: Although significant AVVR developed in most patients within 1 year of repair, the need for repeat valve repair is relatively low if ventricular function is preserved. Ventricular function after repair did not predict late survival but was related to the longevity of AVV competence and subsequent risk for reintervention.

Atrioventricular valve repair in patients with functional single-ventricle physiology: impact of ventricular and valve function and morphology on survival and reintervention.

OBJECTIVE: This study was to determine whether atrioventricular valve repair modifies natural history of single-ventricle patients with atrioventricular valve insufficiency and to identify factors predicting survival and reintervention. METHODS: Fifty-seven (13.5%) of 422 single-ventricle patients underwent atrioventricular valve repair. Valve morphology, regurgitation mechanism, and ventricular morphology and function were analyzed for effect on survival, transplant, and reintervention with multivariate logistic and Cox regression models. Comparative analysis used case-matched controls. RESULTS: Atrioventricular valve was tricuspid in 67% and common in 28%. Ventricular morphology was right in 83%. Regurgitation mechanisms were prolapse (n = 24, 46%), dysplasia (n = 18, 35%), annular dilatation (n = 8, 15%), and restriction or cleft (n = 2, 4%). Postrepair insufficiency was none or trivial in 14 (26%), mild in 33 (61%), and moderate in 7 (13%). Survival in repair group was lower than in matched controls (78.9% vs 92.7% at 1 year, 68.7% vs 90.6% at 3 years, P = .015). Patients with successful repair and normal ventricular function had equivalent survival to matched controls (P = .36). Independent predictors for death or transplant included increased indexed annular size (P = .05), increased cardiopulmonary bypass time (P = .04), and decreased postrepair ventricular function (P = .01). Ventricular dilation was a time-related factor for all events, including failed repair. CONCLUSIONS: Survival was lower in single-ventricle patients operated on for atrioventricular valve insufficiency than in case-matched controls. Patients with little postoperative residual regurgitation and preserved ventricular function had equivalent survival to controls. Lower grade ventricular function and ventricular dilation correlated with death and repair failure, suggesting that timing of intervention may affect outcome.

Primary sutureless repair for infants with mixed total anomalous pulmonary venous drainage.

BACKGROUND: Mixed type total anomalous pulmonary venous drainage (TAPVD) poses technical challenges and high mortality owing to diminutive size and remote location of the pulmonary vein (PV) confluences. We hypothesized that primary application of sutureless repair may better incorporate small and remote confluences, thereby minimizing PV stenosis and improving outcomes. METHODS: Twenty-two consecutive infants (1985 to 2009; median age 27 days; body weight 3.7 kg) with mixed type TAPVD were retrospectively reviewed. Survival and reintervention were compared between the sutureless group (n = 8) and the conventional group (n = 14). Predictors for death and reintervention were identified by an univariate analysis using a chi(2) test. RESULTS: No differences were noted on preoperative and intraoperative variables between the groups. There were 5 early deaths in the conventional group and no deaths in the sutureless group (p = 0.05). There were trends toward improved survival (100% versus 57% at 1 year, p = 0.07) and freedom from reintervention (100% versus 67% at 1 year, p = 0.09) in the sutureless group. The univariate analysis showed that preoperative PV obstruction (p = 0.05), conventional repair (p = 0.05), palliative surgery (p = 0.001), and residual PV obstruction (p = 0.002) were the risk factors for death. Preoperative PV obstruction, palliative surgery, and residual PV obstruction were the predictors for reintervention (p < 0.05 for all). CONCLUSIONS: The primary sutureless repair for the patients with mixed type TAPVD appeared to be safe and effective, resulting in no mortality and reintervention. There were nonsignificant trends toward improving survival and reintervention in the sutureless group. The patients who had sutureless repair and partially unrepaired PV revealed reasonable early and medium-term physiologic tolerance without need for reinterventions.