Search Results

You are looking at 1 - 10 of 21 items for

  • Author or Editor: Steven D. Ham x
Clear All Modify Search
Restricted access

Sandeep Sood, Neelesh Nundkumar and Steven D. Ham

A transfrontal route is the traditional endoscopic approach to intraventricular tumors. Small lesions can be biopsied using the parallel port channel of the endoscope. For larger tumors a ventriculoport can be used for resection. This technique nevertheless requires traversing the brain tissue, is difficult in the setting of small ventricles, and allows only limited mobility. The authors describe the endoscopic resection of large intraventricular tumors via an interhemispheric route using rigid suction with a mounted endoscope, and thus circumventing some of the problems with the traditional approach.

Restricted access

Sandeep Sood, Jaliya Lokuketagoda and Steven D. Ham

Object. The failure of ventricles to enlarge after acute shunt malfunction in long-term shunt-dependent patients is generally attributed to the presence of periventricular rigidity resulting from gliosis. The aim of this study was to test the hypothesis that periventricular rigidity is present in these patients.

Methods. Fifteen pediatric patients who presented with acute shunt malfunction were studied; slit ventricles were detected in all of these patients. Pressure measurements were recorded simultaneously in both the ventricle and the brain parenchyma during shunt revision and then repeated after bolus infusion of fluid into the ventricle.

The mean intraventricular pressure (IVP) at presentation was 24.1 mm Hg (standard deviation 10 mm Hg). The mean baseline IVP after drainage of cerebrospinal fluid but prior to the infusion was 7.5 ± 4.3 mm Hg. There was no significant difference in the increase in the IVP and the intraparenchymal pressure (IPP) after bolus infusion into the ventricle (3.6 ± 2.4 mm Hg and 3.3 ± 2.1 mm Hg, respectively; p = 0.39). The mean pressure volume index was 24.1 ml (standard error of the mean 4.6 ml).

Conclusions. The profile of the changes in IVP and IPP indicates that the periventricular wall does not restrict ventricular enlargement following shunt malfunction in long-term shunt-dependent patients.

Restricted access

Sandeep Sood, Jaliya Lokuketagoda and Steven D. Ham

Object

The failure of ventricles to enlarge after acute shunt malfunction in long-term shunt-dependent patients is generally attributed to the presence of periventricular rigidity resulting from gliosis. The aim of this study was to test the hypothesis that periventricular rigidity is present in these patients.

Methods

Fifteen pediatric patients who presented with acute shunt malfunction were studied; slit ventricles were detected in all of these patients. Pressure measurements were recorded simultaneously in both the ventricle and the brain parenchyma during shunt revision and then repeated after bolus infusion of fluid into the ventricle.

The mean intraventricular pressure (IVP) at presentation was 24.1 mm Hg (standard deviation 10 mm Hg). The mean baseline IVP after drainage of cerebrospinal fluid but prior to the infusion was 7.5 ± 4.3 mm Hg. There was no significant difference in the increase in the IVP and the intraparenchymal pressure (IPP) after bolus infusion into the ventricle (3.6 ± 2.4 mm Hg and 3.3 ± 2.1 mm Hg, respectively; p = 0.39). The mean pressure volume index was 24.1 ml (standard error of the mean 4.6 ml).

Conclusions

The profile of the changes in IVP and IPP indicates that the periventricular wall does not restrict ventricular enlargement following shunt malfunction in long-term shunt-dependent patients.

Restricted access

Sandeep Sood, Ryan J. Barrett, Tiffany Powell and Steven D. Ham

Object

Slit-ventricle syndrome (SVS) is a confusing description of presentations in patients with chronic shunt-treated hydrocephalus. These patients are prone to acute deterioration with recurrent malfunction. The authors describe the clinical profile and management outcome of using lumboperitoneal (LP) shunts in this population of patients.

Methods

Thirty-three patients with slit ventricles and recurrent malfunctions were converted to LP shunts (mean age 12 years). The initial ventricular shunt was placed at a mean age of 16.5 months. Ten patients had failed endoscopic third ventriculostomies prior to placement of their LP shunt. At a previous presentation, in 11 patients suspected to have SVS following revision of the shunt, intracranial pressure normalized after insertion of a contralateral shunt, suggesting that their ventricles were isolated. The rate of infection and malfunction was compared before and after conversion to an LP shunt.

Twenty-seven patients were successfully converted to LP shunts. Four of the 11 patients with isolated ventricles required ventricular shunts in addition to the LP shunt. During a mean follow-up period of 16.7 months, the malfunction rate per patient decreased from 4.81 for ventriculoperitoneal shunts, prior to conversion to 1.48 after conversion to LP shunts, a statistically significant reduction (p < 0.000). No significant difference was found in the rate of shunt infections (7.1% for VP shunts and 9.6% for LP shunts, p = 0.44). No patient presented with acute symptoms following malfunction of an LP shunt or suffered from a Chiari I malformation.

Conclusions

Conversion to an LP shunt is a safe and effective procedure in patients prone to rapid decompensation and recurrent shunt malfunctions from small, slitlike ventricles. The term SVS is confusing. The condition is a manifestation of an unrecognized slitlike isolated ventricle and should be abandoned.

Full access

Neena I. Marupudi, Sandeep Sood, Arlene Rozzelle and Steven D. Ham

OBJECTIVE

Cranial vault expansion is performed in pediatric patients with craniosynostosis to improve head shape. Another argument for performing total cranial vault reconstruction is the potential reduction in the harmful effects of elevated intracranial pressure (ICP) that are associated with craniosynostosis. Alternatively, molding helmets have been shown to improve the cranial index (CI) in patients with sagittal synostosis without surgery. However, it is unknown if the use of molding helmets without surgery contributes to adverse changes in ICP. The effect of molding helmets on ICP and CI in patients with sagittal synostosis was investigated.

METHODS

A prospective cohort study of 24 pediatric patients with sagittal synostosis who planned to undergo total cranial reconstruction was performed from 2011 to 2014 at the Children's Hospital of Michigan. A preoperative molding helmet was used in 13 patients, and no molding helmet was used in 11 patients. End-tidal carbon dioxide, patient positioning, level of sedation, type of anesthetic, and the monitoring site at the time of intraoperative recording were regulated and standardized to establish the accuracy of the ICP readings. CI and head circumference were monitored for each patient.

RESULTS

The mean duration of the preoperative use of the molding helmet was 17 weeks (range 7–37 weeks). Under controlled settings, the average intraoperative ICP was 7.2 mm Hg (range 2–18 mm Hg) for patients treated with a preoperative molding helmet and 9.5 mm Hg (range 2–22 mm Hg) for patients with no preoperative molding helmet. ICP was not significantly different between the 2 groups, suggesting that the use of a molding helmet in this population is safe. The average CI at the time of helmet placement was 0.70 (range 0.67–0.73), and this improved to an average of 0.74 (range 0.69–0.79) after using the molding helmet for a mean of 17 weeks.

CONCLUSIONS

ICPs were not significantly different with the use of a preoperative molding helmet, refuting the prevailing thought that molding helmets would be detrimental in children who have craniosynostosis. The use of molding helmet in this population of patients improves head shape and does not adversely affect ICP.

Restricted access

Sandeep Sood, Holly Gilmer-Hill and Steven D. Ham

Object

The aim of this study was to define the origin and management of lumbar shunt site swelling/cerebrospinal fluid (CSF) leak seen in children who underwent placement of a percutaneous lumbar shunt due to recurrent problems with a ventricular shunt.

Methods

Fifty-seven children with a lumbar shunt were analyzed. Episodes of swelling along the lumbar shunt site, presenting symptoms, origin of the CSF leak, and surgical outcome were recorded.

Results

Twenty patients had 30 episodes of CSF leak/swelling at a mean interval of 92 ± 233 days (± standard deviation) after placement or revision. There were 7 episodes of an external CSF leak; 5 of marked swelling; and 18 episodes of headache, dizziness, and swelling. In 4 patients, the cause of CSF leakage was a fracture/disconnection or dislocation of the proximal catheter. In the remaining patients, CSF leakage was from around the proximal catheter entry point into the spinal dura (with a rate of 16.9% for placement and 15.7% for revision/reinsertion). Interlaminar removal of the existing catheter, microsurgical repair of the leak, and replacement through an opening made with the stylet of a 14-gauge Tuohy needle (Medtronic Neurosurgery) was most effective compared with percutaneous blood patch, pericatheter fascial suture, and percutaneous repositioning of the proximal catheter or downgrading valve pressure.

Conclusions

Lumbar shunt site swelling is predominantly a consequence of pericatheter CSF leakage from the mismatch in the dural opening, which corresponds to the outer diameter of the 14-gauge Tuohy needle and the smaller proximal lumbar catheter. It is best managed by direct repair of the defect through a microsurgical interlaminar approach and recannulation of the dura by using only the stylet of a 14-gauge Tuohy needle.

Restricted access

Sandeep Sood, Martin U. Schuhmann, Nedim Cakan and Steven D. Ham

P The authors describe their experience with endoscopic fenestration of suprasellar cysts followed by shrinkage coagulation of the cysts to restore the anatomy in eight patients.

Seven children ranging in age from 8 months to 4.5 years and one adult 24 years of age were treated. Four of the children presented with megacephaly and the other patients with malfunction of a shunt that had been placed previously for hydrocephalus. Endoscopic fenestration of the cyst dome was performed followed by shrinkage of the lesion by means of endoscopic coagulation. Follow-up studies included immediate and late postoperative magnetic resonance imaging, assessment of growth velocity and the body mass index (BMI), and an endocrine profile if indicated by a failure of growth or precocious puberty.

Good intraoperative cyst shrinkage was achieved in all seven children. This was maintained on imaging studies at a mean follow-up period of 35 months. There was no significant procedure-associated morbidity. Hydrocephalus resolved in four patients who did not have a preexisting shunt. One of the four patients who had a shunt preoperatively became shunt free. The rest of the patients with preexisting shunts remained shunt dependent despite good resolution of the cyst. During a mean follow-up period of 52 months, the height, growth velocity, and BMI of each patient remained within two standard deviations of normal. In one patient there was a suspicion of precocious puberty, but the endocrine profile was normal; in another patient precocious puberty developed and required treatment.

The presented technique is safe and prevents cyst recurrence and obstruction of the aqueduct by remnants of the cyst wall—the two main reasons for failure of a simple endoscopic fenestration.

Restricted access

Sandeep Sood, Cherukuri Ravi Kumar, Mohammad Jamous, Martin U. Schuhmann, Steven D. Ham and Alexa I. Canady

Object. Patients undergoing long-term shunt therapy following shunt malfunction often present with acute neurological deterioration, high intracranial pressure (ICP), and yet small or slit ventricles. It is believed that low brain compliance prevents ventricle enlargement in such cases. To elucidate the underlying pathophysiology, the authors estimated compliance as a function of cerebrovascular distensibility in 45 patients undergoing chronic shunt therapy.

Methods. The ICP and pressure—volume index (PVI) were measured at end-tidal CO2 of 30 mm Hg (PVI30) and 40 mm Hg (PVI40). The ventricle volume was dichotomized as slit/small/normal or dilated based on the frontooccipital horn ratio. In 18 patients PVI30 was normal (18.4 ± 4 ml), whereas in 27 patients it was significantly elevated (45.5 ± 14 ml). Clinical symptoms or ventricle size at presentation did not correlate with the PVI30. The ICP and PVI at end-tidal CO2 of 40 mm Hg were significantly higher than those at end-tidal CO2 of 30 mm Hg (p < 0.001 and < 0.02, respectively) suggesting an increased cerebrovascular distensibility.

Conclusions. The authors did not observe a low compliance in patients undergoing chronic shunt therapy who, at shunt malfunction, presented with a slit/small/normal ventricle; however, analysis of the findings strongly indicated that an increased cerebrovascular distensibility was present in these patients. This may explain the high ICP and acute clinical deterioration following shunt malfunction in such cases.

Free access

Sandeep Sood, Neena I. Marupudi, Eishi Asano, Abilash Haridas and Steven D. Ham

OBJECT

Corpus callosotomy and hemispherotomy are conventionally performed via a large craniotomy with the aid of a microscope for children with intractable epilepsy. Primary technical considerations include completeness of disconnection and blood loss. The authors describe an endoscopic technique performed through a microcraniotomy for these procedures.

METHODS

Four patients with drop attacks and 2 with intractable seizures related to a neonatal stroke underwent endoscopic complete corpus callosotomy and hemispherotomy, respectively. The surgeries were performed through a 2- to 3-cm precoronal microcraniotomy. Interhemispheric dissection to the corpus callosum was done using the standard technique. Subsequently, the bimanual technique with a suction device mounted on an endoscope was used to perform a complete corpus callosotomy, including interforniceal and anterior commissure disconnection. In patients who had hemispherotomy, the fornix was resected posteriorly and lateral disconnection was done by unroofing the temporal horn. Anteriorly, endoscopic corticectomy was done along the ipsilateral anterior cerebral artery to reach the bifurcation of the internal carotid artery to complete the anterior disconnection. Postoperative MRI and diffusion tensor imaging (DTI) of the brain were performed to confirm complete disconnection.

RESULTS

The procedure was accomplished successfully in all patients, with excellent visualization secured. None of the patients required a blood transfusion. Postoperative MRI and DTI confirmed completeness of the disconnection. Patients who underwent corpus callosotomy had complete resolution of drop attacks at a mean follow-up of 6 months, and patients who underwent hemispherotomy became seizure free.

CONCLUSIONS

Endoscopic corpus callosotomy and hemispherotomy are surgically feasible procedures associated with minimal blood loss, minimal risk, and excellent visualization.

Restricted access

Mark R. Proctor and Gary F. Rogers