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J Zoldos

Publications and source records attributed to J Zoldos.

6 recordsLinked to original sources
PubMed1999

Coronal suture response to distraction osteogenesis in rabbits with delayed-onset craniosynostosis.

Recent studies have identified a subpopulation of persons with craniosynostosis who exhibit progressive or delayed-onset synostosis and mild cranial vault deformities. These persons may be good candidates for nonextirpation distraction osteogenesis. The present studies were designed to determine force-displacement parameters and assess the effects of distraction osteogenesis on coronal suture growth and morphologic characteristics in a rabbit model with congenital, delayed-onset craniosynostosis. Data were collected from a total of 178 rabbits: 71 normal controls; 16 normal controls with distraction; 72 with delayed-onset coronal suture synostosis; and 19 with delayed-onset coronal suture synostosis and distraction. At 10 days of age, all rabbits had amalgam markers placed on both sides of the coronal suture. In the force-displacement study, force-displacement distractors were placed across the coronal suture and distracted acutely for 1.0 mm at 42 days of age. Force-displacement curves for the coronal suture were best described by a third-order polynomial regression equation for both normal and synostosed groups. Significant differences (P < 0.05) were found in the mean force necessary to distract a normal suture 1 mm in distance (13.72 kg) compared with a suture with delayed-onset synostosis (48.39 kg). A significant (P < 0.05) relationship was also found between the extent of synostosis and the distractive force in rabbits with delayed-onset synostosis. In the distraction study, internal distractors were fixed across the coronal suture at 25 days of age and percutaneously and intermittently activated at an average of 0.11 mm/day for 42 days (4.54 mm total). Serial radiographs were taken at 10, 25, 42, and 84 days of age. Results revealed that rabbits with delayed-onset synostosis and distraction had significantly (P < 0.01) more coronal suture growth rates compared with rabbits with delayed-onset synostosis and no distraction. Coronal sutures were harvested at 84 days of age for qualitative histologic examination. Normal, distracted coronal sutures showed widened sutural ligaments and thin, active osteogenic fronts. In contrast, distracted coronal sutures from rabbits with delayed-onset synostosis showed narrowed sutural ligaments, thickened and blunt osteogenic fronts, and increased collagen and bony matrix deposition compared with controls. Results suggest that distraction osteogenesis without corticotomy may be a treatment alternative in persons with progressive, delayed-onset synostosis. However, these preliminary data also suggest that distractive forces may accelerate or stimulate osteogenesis differentially in persons with craniosynostosis, possibly through an underlying genetic disorder of bone and cytokine regulation. These differential osteogenic responses to distraction, if validated clinically, will need to be taken into account when planning distraction rate and rhythm protocols for patients with craniosynostosis.

Age of Onset↗
PubMed1998

Venous gangrene of the upper extremity.

Venous gangrene of the upper extremity is a rare entity and is the result of massive occlusion of all venous outflow of the extremity. The syndrome is strongly associated with hypercoagulable states including malignancy, low cardiac output states, and hereditary or acquired hematological abnormalities. Diagnosis can be straightforward but must be made early in the course of the process for treatment to be effective. Treatment has historically produced only modest results, and patients continue to suffer a high morbidity and mortality. We present a series of 6 patients with venous gangrene or impending venous gangrene of the upper extremities--a relatively large series. Two patients suffered from malignancy, 3 patients suffered from low-flow cardiac states, and 1 patient suffered from an overdose of calcium channel blockers. Hematological abnormalities included heparin-induced thrombocytopenia and thrombosis in 3 patients, activated protein C resistance in 1 patient, and lupus anticoagulant in 1 patient. Three patients experienced other major venous thrombotic complications, two of whom died (renal and cerebral venous infarction). Venous gangrene of the upper extremity remains a rare occurrence but one in which early identification and intervention may lead to improved outcomes.

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PubMed1998

Internal calvarial bone distraction in rabbits with delayed-onset coronal suture synostosis.

Recent studies have identified a subpopulation of craniosynostotic individuals who exhibit progressive or delayed-onset synostosis and mild craniofacial growth abnormalities. These individuals may be good candidates for nonextirpation, distraction osteogenesis therapy. The present study was designed to test this hypothesis by using internal calvarial bone distraction in a rabbit model with familial delayed-onset craniosynostosis. Data were collected from 159 rabbits: 71 normal controls, 72 with delayed-onset coronal suture synostosis, 8 with delayed-onset coronal suture synostosis and coronal suturectomy, and 8 with delayed-onset coronal suture synostosis and distraction. At 10 days of age, all rabbits had amalgam markers placed on both sides of the frontonasal, coronal, and anterior lambdoidal sutures. At 25 days of age, correction was accomplished through either a 5-mm-wide suturectomy or distraction osteogenesis. An internal distraction appliance was fixed to the frontal and parietal bones and percutaneously and intermittently activated at an average of 0.10 mm/day for 42 days (4.11 mm total). Serial radiographs were taken at 10, 25, 42, and 84 days of age. Results revealed that rabbits with delayed-onset synostosis had significantly (p < 0.01) reduced coronal suture growth rates (0.04 mm/day) compared with the other three groups (0.07 mm/day). Rabbits with suturectomy and rabbits with distraction showed similar coronal suture responses. However, from 42 to 84 days of age, rabbits with distraction showed reduced growth at the vault sutures and abnormal growth patterns in cranial vault width, cranial vault shape, and cranial base angulation compared with the other three groups. Results demonstrated that, although the normal coronal suture growth rate was maintained in rabbits with delayed-onset synostosis using intermittent distraction osteogenesis, normal adult craniofacial structure was not achieved. Such anomalous growth was probably a result of altered growth vectors and compressive forces at adjacent sutures during distraction. These findings suggest that distraction osteogenesis without corticotomy may be a treatment alternative in individuals with progressive, delayed-onset synostosis, but that internal appliances that generate low-level, continuous distractive forces should be investigated and developed.

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PubMed1997

Ultrasonic prenatal diagnosis of coronal suture synostosis.

The present study was designed to assess the utility and validity of standard prenatal ultrasonography in identifying individuals with coronal suture synostosis by examining sutural abnormalities before the development of secondary craniofacial dysmorphologies. An Accusson 128 XP ultrasound machine was used to scan the coronal sutures of 31 twenty-five-day-old fetuses (term = 31 days) from four timed-pregnant New Zealand White rabbits with simple, nonsyndromic craniosynostosis. Each mother was sedated with general anesthesia, and the gravid uterine horns were exposed via a laparotomy procedure. The fetal calvariae were examined using a no. 7 transducer at 7.0 mHz. Each coronal suture was scanned using ultrasonography by first identifying bregma (the anterior fontanelle) at the intersection of the sagittal, interfrontal, and coronal sutures and then following the coronal sutures laterally. Seventeen of the 31 fetuses were diagnosed with unilateral or bilateral coronal suture fusion. In fetuses with synostosis, the suture was echolucent and patent in the midline but then rapidly tapered off to fused bone as it progressed laterally. This finding is in accordance with the natural history of the synostotic foci and coronal suture fusion progression in these rabbits. In addition, the sagittal and interfrontal sutures in each synostotic rabbit appeared wider along their course compared with normal. This reflects early enhanced compensatory transverse growth resulting from the anteroposterior growth restrictions from coronal suture fusion. No other cranial shape abnormalities were recognizable at this stage of fetal development. The validity of the ultrasound diagnoses was tested by direct ex utero inspection of 9 of the 17 synostotic fetuses. Gross morphological examination showed that 8 of 9 rabbit fetuses (89%) had fused coronal sutures. Statistical analysis revealed no significant difference (chi 2 = 0.22, P > 0.05) between the diagnostic accuracy of standard ultrasonography and direct examination. In conclusion, we have shown that standard ultrasonography of the calvarial sutures, in the absence of other craniofacial malformations, may be a feasible method of diagnosing simple, nonsyndromic craniosynostosis in utero, a condition that is typically missed during routine prenatal ultrasonic screening examinations.

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