Biomedical subjects

D Zurakowski

Publications and source records attributed to D Zurakowski.

At least 145 records · Page 8Linked to original sources

PubMed1997

Developmental restriction of embryonic calvarial cell populations as characterized by their in vitro potential for chondrogenic differentiation.

The mechanism(s) by which the cells within the calvaria tissue are restricted into the osteogenic versus the chondrogenic lineage during intramembranous bone formation were examined. Cells were obtained from 12-day chicken embryo calvariae after tissue condensation, but before extensive osteogenic differentiation, and from 17-day embryo calvariae when osteogenesis is well progressed. Only cell populations from the younger embryos showed chondrogenic differentiation as characterized by the expression of collagen type II. The chondrocytes underwent a temporal progression of maturation and endochondral development, demonstrated by the expression of collagen type II B transcript and expression of collagen type X mRNA. Cell populations from both ages of embryos showed progressive osteogenic differentiation, based on the expression of osteopontin, bone sialoprotein, and osteocalcin mRNAs. Analysis using lineage markers for either chondrocytes or osteoblasts demonstrated that when the younger embryonic cultures were grown in conditions that were permissive for chondrogenesis, the number of chondrogenic cells increased from approximately 15 to approximately 50% of the population, while the number of osteogenic cells remained almost constant at approximately 35-40%. Pulse labeling of the cultures with BrdU showed selective labeling of the chondrogenic cells in comparison with the osteogenic cells. These data indicate that the developmental restriction of skeletal cells of the calvaria is not a result of positive selection for osteogenic differentiation but a negative selection against the progressive growth of chondrogenic cells in the absence of a permissive or inductive environment. These results further demonstrate that while extrinsic environmental factors can modulate the lineage progression of skeletal cells within the calvariae, there is a progressive restriction during embryogenesis in the number of cells within the calvaria with a chondrogenic potential. Finally, these data suggest that the loss of cells with chondrogenic potential from the calvaria may be related to the progressive limitation of the reparative capacity of the cranial bones.

Animals↗

PubMed1997

Vitreous body glutamate concentration in dogs with glaucoma.

OBJECTIVE: To analyze the vitreal amino acid concentrations in dogs with breed-related primary glaucoma to determine whether excitotoxic amino acids associated with retinal genglion cell death in other species were present in affected dogs. SAMPLES: 11 normal control and 10 glaucomatous canine eyes. PROCEDURE: Amino acid analyses were performed by high-pressure liquid chromatography in masked manner. RESULTS: Eyes from dogs with primary glaucoma had significantly high vitreal glutamate concentration, compared with values for eyes of clinically normal control dogs. Mean (+/-SD) glutamate concentrations were 31.7 +/- 12.4 and 6.9 +/- 6.3 microM in glaucomatous and normal eyes, respectively (P < 0.0001). Eyes from dogs with glaucoma also had lower vitreal glycine (37.0 +/- 17.0 vs 59.4 +/- 28.2 microM; P < 0.043) and higher of vitreal tryptophan (39.0 +/- 22.8 vs 17.5 +/- 11.2 microM; P < 0.012) concentrations, compared with values for normal eyes. CONCLUSION: Glutamate concentration potentially toxic to retinal ganglion cells is associated with the pathogenesis of primary glaucoma in dogs. Increased glutamate concentration provides evidence of an ischemic mechanism for retinal ganglion cell death and optic nerve atrophy in dogs with glaucoma. CLINICAL RELEVANCE: The emphasis on reduction and normalization of high intraocular pressure as the primary focus of treatment for glaucoma in dogs should be augmented by other therapeutic approaches.

Amino Acids↗

PubMed1997

Pyrexia after total knee replacement. A cause for concern?

Ninety patients who had undergone 92 total knee replacements were reviewed to determine predictors of postoperative pyrexia and to evaluate the relative value of septic screening in this group of patients. Postoperative pyrexia was defined as an axillary temperature greater than 37 degrees C (98.4 degrees F) on any or all of the 5 days after surgery. All of the patients in this series developed a postoperative pyrexia after knee arthroplasty. None of 16 patients (17% of arthroplasties) with a temperature of 39 degrees C (102 degrees F) or greater had evidence of infection. None of the 4 patients with urinary tract infections developed a pyrexia exceeding 38 degrees C (101 degrees F). At a minimum of 2 years' follow-up, none of the 90 patients had developed an infected arthroplasty. Logistic regression analysis showed that the risk of becoming significantly febrile (temperature > 39 degrees C) doubled for every unit drop in hematocrit and increased fourfold for each unit of blood transfused after surgery. Perioperative blood loss and pyrexia were correlated, but the correlation was not statistically significant. The duration of procedure, tourniquet time, and patient age or sex were not associated with risk of pyrexia. In this series, there was no association between a pyrexia greater than 37 degrees C, septic screening, and the presence of an infective focus. Early postoperative pyrexia after arthroplasty is a normal physiological response, and a significant pyrexia can be predicted by a drop in hematocrit and/or after postoperative transfusion. Pyrexia in the early postoperative period following total knee arthroplasty warrants detailed laboratory and radiographic investigation only in the presence of positive physical findings.

Aged↗

PubMed1997

The role of neuronal and endothelial nitric oxide synthase in retinal excitotoxicity.

PURPOSE: Nitric oxide synthase (NOS) plays an essential role in neuronal function and is critical in the brain for normal and pathologic responses to glutamate. The role of NOS in the retina is less well understood. The retina provides an experimental system in which the intrinsic circuitry is well defined; retinal excitotoxic damage has been well characterized. METHODS: To determine whether neuronal NOS (nNOS) and endothelial NOS (eNOS) are critical in excitotoxic damage in the retina, nNOS- and eNOS-deficient mice were subjected to intravitreal injections of N-methyl-D-aspartate (NMDA) or to arterial occlusions. RESULTS: Retinal ganglion cells in the nNOS-deficient mouse were relatively resistant to NMDA and to arterial occlusion. In contrast, the damage in the eNOS-deficient mouse retina was not distinguishable from that in control animals. Preinjection with an NOS inhibitor was partially protective. CONCLUSIONS: The presence of nNOS is a prerequisite for the full expression of excitotoxicity in the retina; eNOS does not appear to play a significant role.

Animals↗

PubMed1996

Postnatal addition of satellite cells to parasympathetic neurons.

We have examined the postnatal development of satellite cells associated with parasympathetic neurons of mouse salivary duct ganglia. The number of satellite cells associated with each neuron was found to increase during the first 8 weeks after birth but remained constant thereafter. This corresponds to the period of maximal growth of the salivary gland that serves as the target organ innervated by these neurons. At all ages examined, the number of satellite cells associated with each neuron was found to be highly correlated with neuronal volume. The development of satellite cells associated with individual identified neurons was followed directly by in vivo video microscopy over several months, and the number of satellite cell nuclei was found to increase in regions of the neuronal surface with increasing numbers of synaptic boutons. These results indicate that the postnatal addition of satellite cells to parasympathetic neurons is linked to neuronal enlargement and that synaptic remodeling occurs in concert with satellite cell development.

Animals↗

PubMed1996

Elevated glutamate levels in the vitreous body of humans and monkeys with glaucoma.

OBJECTIVE: To explore the possibility that the excitatory amino acid glutamate might be associated with the disease process of glaucoma, which is characterized by the death of retinal ganglion cell neurons and subsequent visual dysfunction. METHODS: Amino acid analyses were performed on vitreous specimens that were obtained from patients who were undergoing cataract extraction. Samples were collected prospectively from those patients who sustained inadvertent rupture of the posterior capsule between 1988 and 1993. An additional set of specimens, obtained from both eyes of monkeys, was analyzed; in these monkeys, glaucoma had been experimentally induced in one eye only. RESULTS: A twofold elevation in the level of glutamate was detected in the vitreous body of the group of patients with glaucoma when compared with that in a control population of patients with cataracts only. An even greater elevation of the glutamate level was found in the vitreous body of glaucomatous eyes of monkeys when compared with that in control eyes. No statistical differences were detected among other amino acid levels from the vitreous body of glaucomatous and nonglaucomatous eyes in humans or monkeys. CONCLUSIONS: The excitatory amino acid glutamate is found in the vitreous body of glaucomatous eyes at concentrations that are potentially toxic to retinal ganglion cells. The increased level of this known neurotoxin is consistent with an "excitotoxic" mechanism for the retinal ganglion cell and optic nerve damage in glaucoma. Therapies to protect neurons against glutamate toxic effects may prove to be useful in the management of this blinding disease.

Aged↗

PubMed1996

Osteoid osteoma: comparative utility of high-resolution planar and pinhole magnification scintigraphy.

A characteristic scintigraphic pattern of focally intense skeletal tracer uptake surrounded by less prominently increased uptake has been described for osteoid osteomas. Demonstration of this finding is useful in the evaluation of patients with suspected osteomas. Pinhole magnification scintigraphy was significantly more effective than high-resolution planar scintigraphy at revealing this pattern in 19 osteoid osteomas of the appendicular skeleton. A similar advantage was not observed for vertebral osteoid osteomas. The absence of the characteristic pattern aided in differentiating other pathology from osteoid osteomas in seven patients. The authors recommend that skeletal scintigraphy of patients with suspected osteoid osteomas include pinhole magnification imaging.

Adolescent↗

PubMed1996

Respiratory insufficiency at birth: a predictor of mortality for infants with omphalocele.

For infants with omphalocele, the size of the defect and the presence of associated anomalies are well known prognostic factors. However, the prognostic importance of the respiratory status at birth has not been well defined. The authors reviewed the records of 30 infants with omphalocele (treated during a 10-year period) to determine whether respiratory insufficiency at birth affected survival. Eighteen infants did not require ventilatory support before repair of the omphalocele. The mean gestational age and birth weight were 38.2 +/- 2.6 weeks and 3.4 +/- 0.6 kg, respectively. Cardiac or other major associated anomalies were present in six infants (33%). Seven (39%) had a "giant" omphalocele (ie, liver-containing and/or omphalocele sac > 5 cm in diameter). The average length of ventilatory support was 3.2 days. All infants in this group were managed by primary (14) or staged closure of the omphalocele (4) immediately after birth. One infant died, but the remainder survived without any significant complications. Twelve infants had severe respiratory distress at birth and required positive pressure ventilation (mean peak inspiratory pressure, 31.4 +/- 1.2 cm H2O; mean FiO2, 0.8 +/- 0.1). The mean gestational age and birth weight were 32.7 +/- 3.5 weeks and 1.9 +/- 0.8 kg, respectively. Cardiac or other major associated anomalies were present in nine infants (75%), and eight (67%) had a giant omphalocele. The average length of ventilatory support was 57.7 days, which was significantly longer than for the previous group (P < 0.001). Two infants died of respiratory failure within 48 hours of birth, before the initiation of any treatment for the omphalocele. Six were managed with surgical repair of the omphalocele, primary or staged, immediately after birth. In four, topical treatment was used to allow improvement in the respiratory status. Only one of the six infants initially managed by surgical repair survived, whereas three of the four infants managed nonsurgically recovered. Stepwise logistic regression analysis showed that the presence of respiratory distress at birth was the only significant predictor of mortality, independent of gender, gestational age, birth weight, presence of other anomalies, or size of the omphalocele (odds ratio = 25.48; likelihood ratio test = 13.86; P < .001). In conclusion, respiratory failure at birth in infants with omphalocele is a significant predictor of mortality. Initial conservative management of the omphalocele until there is improvement in the respiratory status may result in a better outcome.

Case-Control Studies↗

PubMed1996

Structural abnormalities in brain magnetic resonance images of depressed children.

OBJECTIVE: Brain magnetic resonance images (MRIs) of 65 children and adolescents who were hospitalized with depressive disorders (DD) were compared with the brain MRIs of 18 hospitalized psychiatric controls (PC) without a depressive disorder. METHOD: Volumetric analyses were used to measure frontal lobe volumes (FLV), lateral ventricular volumes (VV), and total cerebral volumes (CV) for all subjects. To correct for differences in absolute cerebral volume associated with different body and head size, the ratios of FLV/CV and VV/CV were used to compare differences between the two groups. A multivariate analysis was used to control for the effects of several independent variables (age, sex, diagnosis). RESULTS: Significant differences were seen in the FLV/CV ratio and the VV/CV ratio when the results were compared between the two groups (DD versus PC). The DD group had a significantly smaller FLV/CV ratio (t = 2.148, df = 79, p = .035) and a significantly larger VV/CV ratio (t = -2.093, df = 79, p = .040). CONCLUSION: The findings are consistent with previous reports in depressed adults and may implicate the frontal lobes in the pathogenesis of early-onset depressive disorders.

Adolescent↗

PubMed1996

Elevation of serum interleukin-6 but not serum-soluble interleukin-2 receptor in children with Crohn's disease.

Previous studies have demonstrated elevated serum levels of interleukin-6 (IL-6) and the soluble interleukin-2 receptor (IL-2R, CD25) in individuals with inflammatory bowel disease (IBD). The aim of our study was to compare serum IL-6 and IL-2R levels to see if one marker better distinguished IBD from other intestinal disorders or better reflected disease activity. Blood samples were obtained from 41 pediatric patients with Crohn's disease, 22 with ulcerative colitis, 19 with other gastrointestinal inflammatory disorders, and 13 with functional abdominal pain. Disease activity and disease location were determined for patients with Crohn's disease and ulcerative colitis. Serum levels of IL-6 and IL-2R were determined by using an enzyme-linked immunosorbent assay. Mean serum levels of IL-6 were significantly elevated (p < 0.05) in patients with Crohn's disease when compared with individuals with ulcerative colitis, other gastrointestinal inflammatory disorders, or functional abdominal pain. By comparison, there was no significant difference in mean serum levels of IL-2R in individuals with Crohn's disease compared with these other groups. Patients with moderate/severe Crohn's disease had elevated mean serum levels of IL-6 and IL-2R when compared with those with mild and inactive disease (p < 0.05); however, neither marker distinguished between inactive and mild disease. IL-6 correlated better with the erythrocyte sedimentation rate (ESR; r = 0.57, p < 0.001) than did IL-2R (r = 0.28, p < 0.01). Our results suggest that elevated IL-6 levels a.e more likely to be seen in patients with Crohn's disease. Although IL-6 may be a better marker for Crohn's disease and active disease than IL-2R, it does not appear to offer any advantage over the ESR.

Adolescent↗

PubMed1996

Ten-year experience with the artificial urinary sphincter in children.

PURPOSE: To assess the efficacy of the artificial urinary sphincter survival and continence were first evaluated 5 years ago. We now evaluated the effects of the artificial urinary sphincter more than a decade after implantation. MATERIALS AND METHODS: Before 1985 an artificial urinary sphincter was implanted in 22 male and 14 female consecutive patients 4 to 30 years old (median age 12). In addition, between 1985 and 1990, 18 other children underwent artificial urinary sphincter implantation. Results of both series were compared. RESULTS: Of the 25 sphincters in the original series that were functioning after 5 years 1 was removed and 2 patients were lost to followup, resulting in 22 functioning implants (61% of the patients). Mean survival time of the prostheses was 12.1 years and average followup for functioning sphincters was 13.7 years. There was no statistically significant difference in artificial urinary sphincter survival between the original group at 5 years and the second group treated after 1985. Of the patients in both groups with sphincters in place 32 of 39 (82%) were dry. Augmentation cystoplasty was performed in 9 of 18 patients (50%) in the second series (5 preoperatively and 4 postoperatively) compared to 10 of 36 (28%) in the original series at 5 years (3 preoperatively and 7 postoperatively). Renal failure developed in 6 patients from both series. CONCLUSIONS: The artificial urinary sphincter is a durable long-term solution for children with intractable incontinence. Long-term surveillance of the urinary tract is mandatory because of the potential for renal failure in patients who have bladder hypertonicity after placement of the device.

Adolescent↗

PubMed1996

Functional bladder capacity measured during radionuclide cystography in children.

PURPOSE: To estimate functional bladder capacity (FBC) during direct radionuclide cystography and to assess the relationship between vesicoureteral reflux and FBC. MATERIALS AND METHODS: By using 5,165 direct radionuclide cystograms in patients aged newborn to 14 years, linear and nonlinear models were fit to estimate FBC from age. Analysis was performed on girls and boys separately. In a subgroup, height and weight were evaluated as predictors of FBC. Linear models were used to assess differences in predicted FBC according to sex and reflux status. RESULTS: The relationship between FBC and age is best described by a nonlinear power function. Percentiles derived from this model are close to the empiric percentiles of FBC. When controlling for age, girls and patients with reflux had larger bladder capacities (P < .01). Height and weight did not improve FBC prediction accuracy. CONCLUSION: FBC follows a curve with increasing age. The nonlinear relationship between FBC and age appears to be consistent with maturation in infants and children.

Adolescent↗

PubMed1996

Insulin-like growth factor II affects the appearance and glycogen content of glycogen cells in the murine placenta.

The phenotype of mice with a targeted disruption of the insulin-like growth factor II gene (IGF-II null mice) is growth retardation of both fetus and placenta during the last two thirds of gestation (1). We have compared the placenta of IGF-II null and wild-type mice from days 9-18 of gestation. No morphological differences were detected until after day 12 of gestation, when a new population of placental cells, the glycogen cells, normally first appears. Fewer glycogen cells were present in the null placenta compared to the wild-type placenta on days 13, 15, and 18 of gestation. By day 15, glycogen cells constituted approximately 50% of the basal zone cells in the wild-type placenta, but only 20% of the basal zone cells in the null placenta (P < 0.01). By contrast, spongiotrophoblasts constituted 40% of the basal zone cells in the wild-type placenta and 70% of the basal zone cells in the null placenta. There were no differences in cell size at any time. These results suggest that glycogen cells do not efficiently differentiate in the absence of IGF-II. The differentiation of glycogen cells did not appear to be simply delayed in the null placenta, as the number of glycogen cells in the null placenta did not increase between days 15-18, and there was no change in the ratio of glycogen to spongiotrophoblasts in the basal zone (P > 0.50). The glycogen content of both spongiotrophoblasts and glycogen cells was significantly reduced in the null placenta, suggesting that IGF-II may be an important regulator of glycogen synthesis in the placenta. These results indicate that IGF-II regulates cell number in the placenta and may play an important role in the differentiation of glycogen cells and the production of glycogen by placental cells.

Animals↗

PubMed1996

Variable hormone responsiveness of osteoblast populations isolated at different stages of embryogenesis and its relationship to the osteogenic lineage.

A variable response to 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] hormone treatment was observed for osteoblast cell populations isolated from 12- and 17-day-old embryonic chick calvariae. The younger embryonic cell population showed 2- and 5-fold inductions of osteocalcin and osteopontin gene expression, respectively, and a 25% inhibition of collagen gene expression when treated with 1,25-(OH)2D3. In contrast, these same genes all displayed approximately 80% inhibition of their expression when the older embryonic cell populations were treated with hormone. The hormone response was related to the appearance of the vitamin D3 receptor (VDR) and the developmental state of teh two cell populations by assessing the numbers of cells that were immunologically labeled for two osteoblast lineage, stage-specific surface makers (alkaline phosphatase and SB-5, an osteocyte marker) and the VDR. Using the sequence of marker presentation, with VDR appearing first, followed by alkaline phosphatase and then SB-5, models were tested using logistic regression analysis to validate this order of marker presentation and establish that the two embryonic ages of the cell populations represent discrete stages of their lineage. This analysis indicated that 1,25-(OH)2D3 treatment progressed the 12-day-old embryo cell populations along their lineage and that the hormone promoted the appearance of its own receptor (P < 0.001) However, the appearance of the VDR does not appear to be a determinant in the variable responses of the different embryonic aged cell populations to the hormone. These data quantitatively establish the unique nature of osteoblast cell populations within their lineage progression for cells isolated from embryos of different ages, such that cell populations isolated from younger embryos are comprised of primarily presumptive or immature osteoblasts, whereas cells isolated from older embryos are comprised of mature osteoblasts. These data also demonstrate that the genomic effects of 1,25-(OH)2D3 are dependent on the developmental stage of the osteoblast lineage, and the stimulatory actions of the hormone are targeted to immature osteoblasts, whereas the effect of the hormone on mature osteoblasts is inhibitory.

Animals↗

PubMed1996

E-selectin is present in proliferating endothelial cells in human hemangiomas.

E-selectin, an endothelial-cell-specific leukocyte adhesion molecule, may also function in angiogenesis. To investigate its role in a noninflammatory angiogenic disease, E-selectin was analyzed by immunohistochemistry in specimens of proliferative phase and involutive phase hemangiomas. Hemangioma is an endothelial cell tumor of capillary blood vessels that grows rapidly during infancy and regresses spontaneously during childhood. E-selectin expression was high in proliferative phase specimens and was co-localized with dividing microvascular endothelial cells. Relative to the number of blood vessels, E-selectin declined significantly in involutive phase specimens demonstrating that E-selectin correlates with angiogenesis in the tumors. E-selectin was not detected in quiescent endothelium but was co-localized in dividing microvascular endothelial cells in placenta and neonatal foreskin, two tissues with ongoing growth of microvessels. These in vivo studies support the hypothesis that E-selectin functions in angiogenesis and suggest that E-selectin may be a marker for proliferating endothelium.

Antibodies, Monoclonal↗

PubMed1996

Chronic low-dose glutamate is toxic to retinal ganglion cells. Toxicity blocked by memantine.

PURPOSE: It is well known that acute exposure to high concentrations of glutamate is toxic to central mammalian neurons. However, the effect of a chronic, minor elevation over endogenous glutamate levels has not been explored. The authors have suggested that such chronic exposure may play a role in glaucomatous neuronal loss. In the current study, they sought to explore whether a chronic, low-dose elevation in vitreal glutamate was toxic to retinal ganglion cells and whether this toxicity could be prevented with memantine, a glutamate antagonist. METHODS: Rats were injected serially and intravitreally with glutamate to induce chronic elevations in glutamate concentration. A second group of rats was treated with intraperitoneal memantine and glutamate. Control groups received vehicle injection with or without concurrent memantine therapy. After 3 months, the animals were killed, and ganglion cell survival was evaluated. RESULTS: Intravitreal injections raised the intravitreal glutamate levels from an endogenous range of 5 to 12 microM glutamate to 26 to 34 microM. This chronic glutamate elevation killed 42% of the retinal ganglion cells after 3 months. Memantine treatment alone had no effect on ganglion cell survival. However, when memantine was given concurrently with low-dose glutamate, memantine was partially protective against glutamate toxicity. CONCLUSIONS: These data suggest that minor elevations in glutamate concentration can be toxic to ganglion cells if this elevation is maintained for 3 months. Furthermore, memantine is efficacious at protecting ganglion cells from chronic low-dose glutamate toxicity.

Animals↗

PubMed1996

Natural history of vesicoureteral reflux in siblings.

PURPOSE: We attempted to assess the natural course of vesicoureteral reflux after it was detected in asymptomatic siblings of children with reflux, and to determine predictors of and time to resolution. MATERIALS AND METHODS: We reviewed the records and radionuclide cystograms of 76 girls and 32 boys 2 weeks to 103 months old (mean age 21 months) with vesicoureteral reflux detected in a sibling screening program. Predictors were determined using logistic regression and survival analysis. RESULTS: Vesicoureteral reflux resolved in 52.8% of cases at a mean followup of 18.5 months. Yearly resolution rates exceeded 28%. Predictors of the likelihood of resolution were not identified. At diagnosis unilateral reflux and mild reflux were independent and univariate predictors, respectively, of more rapid resolution. CONCLUSIONS: By showing that spontaneous resolution is likely for children with vesicoureteral reflux detected in a sibling screening program, this study supports nonsurgical management with annual imaging evaluation.

Child↗

PubMed1995

Sternotomy approach for the modified Blalock-Taussig shunt.

BACKGROUND: Since 1990, sternotomy has been the preferred approach for construction of a modified Blalock-Taussig shunt (MBTS) at Children's Hospital, Boston, Mass. In retrospect, we sought to test the hypothesis that this approach yields less mortality and morbidity than the traditional thoracotomy approach. METHODS AND RESULTS: One hundred four primary MBTSs with polytetrafluoroethylene grafts were constructed in patients from January 1988 through December 1992. Fifty-two shunts were constructed by thoracotomy approach and 52 by sternotomy approach. Fifteen of the thoracotomy patients were less than one month of age (8 less than 7 days), while 36 of the sternotomy patients were less than 1 month of age (20 less than 7 days). There were 10 shunt failures and 3 hospital deaths in the thoracotomy group and 4 shunt failures with 6 hospital deaths in the sternotomy group. The overall hospital mortality rate for the group was 8.7% (9 of 104). The operative route was not a significant predictor of hospital mortality (P = .30). However, there was a significant difference between the two operative approaches in shunt failure, with shunts that were created by thoracotomy four times more likely to fail than those created by the sternotomy route (odds ratio, OR, 3.88; 95% CI, 1.01 to 15.03; P = .049). The side of the shunt was also a significant predictor of failure with left-side MBTSs foru times more prone to failure (OR, 4.02; 95% CI, 1.19 to 15.25; P = .025). CONCLUSIONS: The sternotomy route is technically less challenging and is associated with fewer shunt failures than the classic thoracotomy approach. The potential theoretical disadvantages of this method for future sternal reentry for subsequent procedures was not apparent but requires prospective analysis.

Adolescent↗