Carl B. Heilman

Prenatal Diagnosis and the Pediatric Surgeon: The Impact of Prenatal Consultation on Perinatal Management

PURPOSE Pediatric surgeons are increasingly called on by obstetrical colleagues to counsel parents about the implications of a prenatal ultrasound finding. Our understanding of the natural history of many prenatally diagnosed surgical conditions has grown significantly in recent years. Whether prenatal surgical consultation can influence perinatal course had not been investigated. METHODS During an 21-month period, 12,865 prenatal ultrasound studies were performed on a total of 4,551 patients, and 221 prenatal surgical consultations were obtained through a newly established fetal treatment program at a tertiary care prenatal diagnostic center. To evaluate the impact of prenatal pediatric surgical consultation on perinatal course, the authors reviewed changes in management including termination of pregnancy, in utero intervention, and altered site, mode, or timing of delivery. RESULTS Two hundred twenty-one fetuses were referred for consultation; their 234 congenital anomalies included genitourinary (36%), thoracic (16%), intraabdominal (14.5%), abdominal wall (10.6%), neurological (9%), skeletal (6%), and head and neck (2.5%) defects; 2.5% had tumors and 2.5% were twin pregnancies. Pregnancy was terminated in 9.5% of cases, because of patient request, chromosomal abnormality, or dismal prognosis. In 3.6%, the decision to terminate was changed as a result of consultation. Site of delivery was changed as a result of consultation in 37% to facilitate postnatal evaluation and initiate immediate treatment. Mode of delivery was changed in 6.8% to prevent dystocia, hemorrhage into a tumor, as in sacrococcygeal teratoma, or to provide an emergency airway, as in cervical teratoma. The timing of delivery was changed in 4.5% to avoid further damage to fetal organs in cases of obstructive uropathy, gastroschisis, sacrococcygeal teratoma with high-output failure, and hydrocephalus. Five percent (11) underwent treatment in utero for fetal hydrothorax, obstructive uropathy, twin-twin transfusion syndrome, or lymphangioma. The overall perinatal mortality rate was 2.5%. CONCLUSION Prenatal pediatric surgical consultation may have a significant impact on the perinatal management of the fetus with a surgically correctable congenital anomaly. Providing obstetric colleagues and families with valuable insight into the surgical management of anomalies allows fetal intervention when appropriate, and delivery in an appropriate setting, by the safest mode of delivery, and at the gestational age appropriate to minimize effects of the anomaly.

Pneumocephalus: Case Illustrations and Review

BackgroundPneumocephalus is commonly encountered after neurosurgical procedures but can also be caused by craniofacial trauma and tumors of the skull base and rarely, can occur spontaneously. Contributing factors for the development of pneumocephalus include head position, duration of surgery, nitrous oxide (N2O) anesthesia, hydrocephalus, intraoperative osmotherapy, hyperventilation, spinal anesthesia, barotauma, continuous CSF drainage via lumbar drain, epidural anesthesia, infections, and neoplasms. Clinical presentation includes headaches, nausea and vomiting, seizures, dizziness, and depressed neurological status. In this article, we review the incidence, mechanisms, precipitating factors, diagnosis, and management of pneumocephalus. Search of Medline, databases, and manual review of article bibliographies. Considering four case illustrations that typify pneumocephalus in clinical practice, we discuss the common etiologies, and confirm the diagnosis with neuroimaging and management strategies. Avoidance of contributing factors, high index of suspicion, and confirmation with neuroimaging are important in attenuating mortality and morbidity. A significant amount of pneumocephalus can simulate a space-occupying lesion. Supplemental oxygen increases the rate of absorption of pneumocephalus.

Endoscopic Sphenoidotomy Approach to the Sella

OBJECTIVE Advances in optics, miniaturization, and endoscopic instrumentation have revolutionized surgery in the past decade. We report our experience with the endoscope in nine patients with sellar lesions who underwent an endoscopic sphenoidotomy approach to the sella. METHODS An endoscopic transnasal cavity sphenoidotomy approach without a septal dissection was used in the resection of pituitary adenomas and other sellar lesions. RESULTS This approach provided excellent exposure of the sella and adequate working space. The technique produces less postoperative pain and, in some cases, shortens hospital stay. The sphenoidotomy approach eliminates the problems of lip numbness, septal perforations, and oronasal fistulas. CONCLUSION The endoscopic sphenoidotomy approach has become our preferred approach to sellar lesions.

Meningiomas of the cerebellopontine angle

BACKGROUND Meningiomas of the cerebellopontine angle (CPA), although uniform in location, are diverse with regard to the site of dural origin and displacement of neurovascular structures. A study of patients with CPA meningiomas was undertaken to gain more information regarding the relationship between site of dural attachment, clinical presentation, operative approach, and outcome. METHODS In this report, we retrospectively review 40 patients with CPA meningiomas managed surgically. RESULTS Common clinical presentations were hearing loss, unsteadiness, and dysequilibrium. Findings upon physical examination included hearing loss (73%), cerebellar signs (32%), trigeminal neuropathy (16%), and facial nerve dysfunction (16%). The most common site of dural origin was the petrous ridge (anterior to the IAC [26%], posterior [21%], superior [18%], and inferior [16%]). Less common sites of dural origin included the tentorium (31%), the clivus (15%), the IAC (10%), and the jugular foramen (8%). Site of dural origin determined the direction of displacement of the facial/vestibulocochlear nerve bundle. The most common microsurgical complication was facial nerve dysfunction (30%). Gross total resection was achieved in 82% of cases, whereas 18% underwent subtotal resection. Two patients died. Follow-up ranged from three months to 13 years with three recurrences. CONCLUSIONS CPA meningiomas displace the seventh and eighth cranial nerves in various directions depending on the site of dural origin. Total surgical excision can be accomplished in the majority of cases with acceptable morbidity.

Microsurgical Anatomy of the Infratemporal Fossa as Viewed Laterally and Superiorly

OBJECTIVE Benign tumors involving cavernous sinus, trigeminal nerve, and middle cranial fossa occasionally extend to the infratemporal fossa (ITF). In this study, we describe the microsurgical anatomy and dissection of the ITF, as viewed laterally and superiorly. We also describe a new bypass graft to the supraclinoid internal carotid artery using the internal maxillary artery (IMA), which is found in the ITF. METHODS Twelve cadaver specimens were used. Dissection required zygomatic arch osteotomy, downward displacement of the temporalis muscle, extensive subtemporal craniectomy, and mild elevation of the temporal lobe together with the dura. RESULTS The anatomic relationships between the lateral and medial pterygoid muscles and the neurovascular bundle of the ITF are demonstrated. The neurovascular bundle contains the IMA, which runs horizontally, and the main branches of the mandibular nerve, which run vertically. The course and anatomic variations of the IMA and inferior alveolar, lingual, auriculotemporal, and buccal nerves are shown. The distal IMA was quite tortuous and, when the artery straightened, we were able to perform a tension-free in situ IMA graft to the supraclinoid carotid artery in 9 of 12 specimens. CONCLUSIONS Knowledge of the anatomy of the ITF is a prerequisite for tumor resection in this area. The IMA may serve as a bypass graft to the supraclinoid internal carotid artery if the cavernous or petrous carotid artery is involved by tumor and needs to be sacrificed.

Functional analysis of third ventriculostomy patency with phase-contrast MRI velocity measurements

Abstract Our purpose was to explore the utility of cine phase-contrast MRI velocity measurements in determining the functional status of third ventriculostomies, and to correlate the quantitative velocity data with clinical follow-up. We examined six patients with third ventriculostomies and 12 normal subjects by phase-contrast MRI. The maximum craniocaudal to maximum caudocranial velocity range was measured at regions of interest near the third ventricular floor, and in cerebrospinal fluid anterior to the upper pons and spinal cord on midline sagittal images. Ratios of the velocities of both the third ventricle and prepontine space to the space anterior to the spinal cord were obtained. The velocities near the third ventricular floor and in the pontine cistern were significantly higher in patients than in normal subjects, but the velocity anterior to the spinal cord was similar between the groups. The velocity ratios, used to normalize individual differences, were also higher in patients than in controls. Two patients had lower velocity ratios than their fellows at the third ventricular floor and in the pontine cistern; one required a shunt 11 months later, while in the other, who had a third ventricular/thalamic tumor, the lower values probably reflect distortion of the third ventricular floor. We conclude that phase-contrast MR velocity measurements, specifically the velocity ratio between the high pontine cistern and the space anterior to the spinal cord, can help determine the functional status of third ventriculostomies.

De Novo Development of an Aneurysm: Case Report

A case of the de novo formation of an aneurysm in a young woman is presented. At age 13 years, she had a spontaneous subarachnoid hemorrhage. Cerebral angiography showed an aneurysm of the bifurcation of the left internal carotid artery and a small aneurysm of the left anterior choroidal artery. At surgery, the aneurysm of the internal carotid artery was clipped, and the aneurysm of the left anterior choroidal artery was wrapped with muslin. Thirteen years later, the patient had another subarachnoid hemorrhage. Cerebral arteriography showed four aneurysms that had developed at previously angiographically normal sites. This case suggests that young patients with aneurysms might benefit from follow-up angiography in search of late aneurysm formation.

C1-C2 arthrodesis after transoral odontoidectomy and suboccipital craniectomy for ventral brain stem compression in Chiari I patients.

Chiari I malformations are often associated with congenital craniocervical anomalies such as platybasia, basilar invagination, and retroflexion of the odontoid process. Management of ventral brain stem compression associated with Chiari I malformations remains controversial, but several authors report a significant rate of failure with suboccipital decompression alone in the presence of pronounced ventral brain stem compression (VBSC). Treatment options described in the literature for these patients involve anterior, posterior, or combined decompressions with or without concurrent arthrodesis. A combined anterior and posterior approach provides a definitive circumferential decompression but also significantly disrupts the stability of the occipitocervical junction usually necessitating occipitocervical fixation. We describe an alternative surgical treatment for Chiari I patients with significant ventral brain stem compression where a combined anterior and posterior decompression was considered necessary. We report two patients who underwent transoral odontoidectomy with preservation of the anterior arch of the atlas and suboccipital craniectomy with C1 laminectomy followed by C1–C2 arthrodesis. Preservation of the anterior arch of the atlas in conjunction with C1–C2 arthrodesis stabilizes the occipito–atlanto-axial segments while conserving more cervical mobility as compared to an occipitocervical fusion.

Temporary balloon occlusion of a proximal vessel as an aid to clipping aneurysms of the basilar and paraclinoid internal carotid arteries: technical note.

One aneurysm of the basilar artery and three large, paraclinoid aneurysms of the internal carotid artery (ICA) were treated with the aid of intraoperative temporary balloon occlusion of the vessel. Optimal clip placement was confirmed using intraoperative angiography. This technique provided excellent proximal vascular control and for the large aneurysms of the paraclinoid ICA obviated the need for surgical exposure of the ICA in the neck. We think this is a useful adjunct in the surgical management of aneurysms of both the basilar artery and proximal ICA.

Ventricular access device versus ventriculosubgaleal shunt in post hemorrhagic hydrocephalus associated with prematurity

Objective. Post-hemorrhagic hydrocephalus (PHH) secondary to germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) continues to be a common problem affecting preterm neonates. Two different devices are used to treat hydrocephalus in preterm neonates under 2.5 kg: (1) ventricular access device (VAD) and (2) ventricular to subgaleal shunt (VSGS). We aim to determine the differences between VAD and VSGS in daily patient management and shunt requirement outcome in premature infants with PHH. Method. The medical records of 32 preterm neonates diagnosed with GMH-IVH with PHH treated with a VAD or VSGS were reviewed. The grade of GMH-IVH, need for CSF taps, complications, malfunctions, and need for permanent VP shunt placement were compared between VAD and VSGS groups. Results. All (16/16) VAD patients required daily taps while 4/16 VSGS patients required daily taps. The VAD group had one complication while the VSGS group had five complications. About 28.57% of the patients treated with a VSGS did not require a permanent VP shunt. Around 6.25% of the patients treated with a VAD did not require a permanent VP shunt. Conclusion. VSGS is an effective means of providing temporary continuous drainage of CSF in PHH with an acceptable complication rate. VSGS has many advantages that make it superior to VAD as a temporizing shunt.