Christian A. Bowers, Tamer Altay and William T. Couldwell
Although the transcranial route (TCR) has been the traditional approach for removing tuberculum sellae meningiomas (TSMs), the use of the microscopic and/or more recently the endoscopic transsphenoidal approach (ETSA) has gained acceptance for selected cases. In this study, the authors present their experience with the ETSA and the TCR and examine the criteria most important for deciding the optimal approach in a particular case.
The authors retrospectively reviewed recent cases of TSMs treated surgically by the senior author via either the TCR or the ETSA or both. Demographic information, clinical presentation, and clinical and radiological outcomes of the patients were evaluated.
Twenty-seven patients underwent removal of a TSM during a recent period. Gross-total or near-total resection was achieved in 20 (91%) of 22 patients who underwent resection via the TCR and in 3 (60%) of 5 patients who underwent the ETSA. Among the patients in whom gross- or near-total resection was achieved, recurrence was observed in only 1 patient, whose tumor was removed via the ETSA.
In the majority of patients, the TCR provided complete resection of the tumor without compromising the safety of the procedure. In select cases of tumors with a reasonable size and location (midline and/or extending into the sphenoid sinus) as well as no involvement of inaccessible neurovascular and bony elements via this approach, the ETSA could also be a viable option.
Christian Bowers, Amin Amini, Andrew T. Dailey and Meic H. Schmidt
The X-Stop interspinous device is designed for the treatment of patients with neurogenic intermittent claudication due to lumbar spinal stenosis. It distracts the posterior elements of adjacent vertebral bodies, unloading the intervertebral disc, limiting spinal extension, and improving central canal and neuroforaminal stenosis. In this paper, the authors reviewed the complications and failure/reoperation rates in a small series of patients and compared their results with other reported complication and failure/reoperation rates.
The medical records of all patients who underwent placement of the X-Stop device for the treatment of NIC at the authors' institution were retrospectively evaluated, and demographic information, diagnosis, and preoperative pain levels were recorded. Postoperatively, patients subjectively graded the percentage (0–100%) of improvement in pain as well as the amount of residual pain and underwent imaging at 1-, 3-, and 6-month intervals. Approximately 4 years after X-Stop placement, information on long-term outcomes was obtained from patient medical records or additional follow-up.
Thirteen patients (8 men and 5 women) underwent placement of the X-Stop device. Central canal stenosis with bilateral foraminal stenosis was diagnosed in all patients: 9 (69%) of 13 had severe stenosis and 4 (31%) of 13 had moderate stenosis. Five patients (38%) also had associated Grade I spondylolisthesis. Nine patients underwent placement of the X-Stop device at the L4–5 interspinous space and 4 at both the L3–4 and L4–5 levels. The average duration of follow-up was 42.9 months (range 3–48 months). Initially, pain improved an average of 72% (range 50–100%) in these patients; however, preoperative pain returned in 77% of the patients (10 of 13). The overall complication rate was 38%, including 3 spinous process fractures (23%) and 2 instances of new-onset radiculopathy (15%). The ultimate failure rate requiring additional spinal surgery was 85% (11 of 13 patients). These complication and failure rates are much higher than those previously reported.
Overdistraction, poor bone density, poor patient selection, and preexistent adjacent foraminal stenosis may all be factors in the development of the aforementioned complications. Thus, careful attention should be paid preoperatively to adjacent-level disease, bone density, appropriate implant size, and optimal patient selection.
Heather S. Spader, Robert J. Bollo, Christian A. Bowers and Jay Riva-Cambrin
Intrathecal baclofen infusion systems to manage severe spasticity and dystonia are associated with higher infection rates in children than in adults. Factors unique to this population, such as poor nutrition and physical limitations for pump placement, have been hypothesized as the reasons for this disparity. The authors assessed potential risk factors for infection in a multivariate analysis.
Patients who underwent implantation of a programmable pump and intrathecal catheter for baclofen infusion at a single center between January 1, 2000, and March 1, 2012, were identified in this retrospective cohort study. The primary end point was infection. Potential risk factors investigated included preoperative (i.e., demographics, body mass index [BMI], gastrostomy tube, tracheostomy, previous spinal fusion), intraoperative (i.e., surgeon, antibiotics, pump size, catheter location), and postoperative (i.e., wound dehiscence, CSF leak, and number of revisions) factors. Univariate analysis was performed, and a multivariate logistic regression model was created to identify independent risk factors for infection.
A total of 254 patients were evaluated. The overall infection rate was 9.8%. Univariate analysis identified young age, shorter height, lower weight, dehiscence, CSF leak, and number of revisions within 6 months of pump placement as significantly associated with infection. Multivariate analysis identified young age, dehiscence, and number of revisions as independent risk factors for infection.
Young age, wound dehiscence, and number of revisions were independent risk factors for infection in this pediatric cohort. A low BMI and the presence of either a gastrostomy or tracheostomy were not associated with infection and may not be contraindications for this procedure.
Christian A. Bowers, Jay Riva-Cambrin, Dean A. Hertzler II and Marion L. Walker
Decompressive craniectomy with subsequent autologous cranioplasty, or the replacement of the native bone flap, is often used for pediatric patients with traumatic brain injury (TBI) who have a mass lesion and intractable intracranial hypertension. Bone flap resorption is common after bone flap replacement, necessitating additional surgery. The authors reviewed their large database of pediatric patients with TBI who underwent decompressive craniectomy followed by bone flap replacement to determine the rate of bone flap resorption and identify associated risk factors.
A retrospective cohort chart review was performed to identify long-term survivors who underwent decompressive craniectomy for severe TBI with bone flap replacement from January 1, 1996, to December 31, 2011. The risk factors investigated in a univariate statistical analysis were age, sex, underlying parenchymal contusion, Glasgow Coma Scale score on arrival, comminuted skull fracture, posttraumatic hydrocephalus, bone flap wound infection, and freezer time (the amount of time the bone flap was stored in the freezer before replacement). A multivariate logistic regression model was then used to determine which of these were independent risk factors for bone flap resorption.
Bone flap replacement was performed at an average of 2.1 months after decompressive craniectomy. Of the 54 patients identified (35 boys, 19 girls; mean age 6.2 years), 27 (50.0%) experienced bone flap resorption after an average of 4.8 months. Underlying parenchymal contusion, comminuted skull fracture, age ≤ 2.5 years, and posttraumatic hydrocephalus were significant, or nearly significant, on univariate analysis. Multivariate analysis identified underlying contusion (p = 0.004, OR 34.4, 95% CI 3.0–392.7), comminuted skull fractures (p = 0.046, OR 8.5, 95% CI 1.0–69.6), posttraumatic hydrocephalus (p = 0.005, OR 35.9, 95% CI 2.9–436.6), and age ≤ 2.5 years old (p = 0.01, OR 23.1, 95% CI 2.1–257.7) as independent risk factors for bone flap resorption.
After decompressive craniectomy for pediatric TBI, half of the patients (50%) who underwent bone flap replacement experienced resorption. Multivariate analysis indicated young age (≤ 2.5 years), hydrocephalus, underlying contusion as opposed to a hemispheric acute subdural hematoma, and a comminuted skull fracture were all independent risk factors for bone flap resorption. Freezer time was not found to be associated with bone flap resorption.
Michael Karsy, Hussam Abou-Al-Shaar, Christian A. Bowers and Richard H. Schmidt
Idiopathic intracranial hypertension (IIH), or pseudotumor cerebri, is a complex and difficult-to-manage condition that can lead to permanent vision loss and refractory headaches if untreated. Traditional treatment options, such as unilateral ventriculoperitoneal (VP) or lumboperitoneal (LP) shunt placement, have high complication and failure rates and often require multiple revisions. The use of bilateral proximal catheters has been hypothesized as a method to improve shunt survival. The use of stereotactic technology has improved the accuracy of catheter placement and may improve treatment of IIH, with fewer complications and greater shunt patency time.
The authors performed a retrospective chart review for all patients with IIH who underwent stereotactic placement of biventriculoperitoneal (BVP) shunt catheters from 2008 to 2016 at their institution. Bilateral proximal catheters were Y-connected to a Strata valve with a single distal catheter. We evaluated clinical, surgical, and ophthalmological variables and outcomes.
Most patients in this series of 34 patients (mean age 34.4 ± 8.2 years, mean body mass index 38.7 ± 8.3 kg/m2; 91.2% were women) undergoing 41 shunt procedures presented with headache (94.1%) and visual deficits (85.3%). The mean opening pressure was 39.6 ± 9.0 cm H2O. In addition, 50.0% had undergone previous unilateral shunt placement, and 20.6% had undergone prior optic nerve sheath fenestration. After BVP shunt placement, there were no cases of proximal catheter obstruction and only a single case of valve obstruction at 41.9 months, with a mean follow-up of 24.8 ± 20.0 months. Most patients showed improvement in their headache (82.4%), subjective vision (70.6%), and papilledema (61.5% preoperatively vs 20.0% postoperatively, p = 0.02) at follow-up. Additional primary complications included 4 patients with migration of their distal catheters out of the peritoneum (twice in 1 patient), and an infection of the distal catheter after catheter dislodgment. The proximal obstructive shunt complication rate in this series (2.9%) was lower than that with LP (53.5%) or unilateral VP (37.8%) shunts seen in the literature.
This small series suggests that stereotactic placement of BVP shunt catheters appears to improve shunt survival rates and presenting symptoms in patients with IIH. Compared with unilateral VP or LP shunts, the use of BVP shunts may be a more effective and more functionally sustained method for the treatment of IIH.
Christian A. Bowers, Mohammed Sorour, Bhupendra C. Patel and William T. Couldwell
Meningioma-associated proptosis (MAP) can be cosmetically and functionally debilitating for patients with sphenoorbital and other skull base meningiomas, and there is limited information on the quantitative improvement in proptosis after surgery. Because less extensive removals of tumor involving the orbit fail to reduce proptosis, the senior author has adopted an aggressive surgical approach to the removal of tumor involving the periorbita and orbit. The authors of this study retrospectively reviewed outcomes of this surgical approach.
All surgeries for MAP performed by a single surgeon between January 1, 2002, and May 1, 2015, were reviewed. Age, sex, visual symptoms, number and types of surgical treatments, cavernous sinus involvement, complications, duration of follow-up, residual tumor, use of adjuvant radiation therapy, and extent of proptosis resolution as measured by the exophthalmos index (EI) pre- and postoperatively and at the final follow-up were recorded.
Thirty-three patients (24 female [73%]) with an average age of 51.6 years were treated for MAP. Of the 22 patients with additional visual symptoms (for example, loss of visual acuity, field cut, or diplopia), 15 had improved vision and 7 had stable vision. No patients had worse proptosis after treatment. The average preoperative EI was 1.39, the average immediate postoperative EI was 1.23, and the average final EI at the most recent follow-up was 1.13. Thus, average overall EI improvement was 0.26, but the average immediate EI reduction was 0.16, demonstrating that proptosis progressively improved during the postoperative period. Residual cavernous sinus involvement was present in 17 of 18 patients who had had preoperative cavernous sinus meningioma involvement. Only 2 patients in the series had recurrent tumor at the orbital region, and their proptosis improved again after reoperation. One case of delayed vasospasm and 2 cases of postoperative trigeminal numbness (V2) were recorded. The average follow-up was 4.5 years (53.8 months).
In this series, all patients experienced proptosis improvement and none had worse visual symptoms at the final follow-up, although proptosis resolution occurred over time. Only 2 patients had tumor recurrence at the orbit that required surgery. Surgical complications were uncommon. Study results suggest that aggressive resection of MAP is well tolerated and offers superior proptosis elimination with infrequent recurrence at the orbit. Importantly, no cases of enophthalmos were noted despite the lack of formal reconstruction of the orbit.
Christian A. Bowers, Jaron H. McMullin, Cameron Brimley, Linsey Etherington, Faizi A. Siddiqi and Jay Riva-Cambrin
Occasionally after a craniotomy, the bone flap is discarded (as in the case of osteomyelitis) or is resorbed (especially after trauma), and an artificial implant must be inserted in a delayed fashion. Polyetheretherketone (PEEK) implants and hard-tissue replacement patient-matched implants (HTR-PMI) are both commonly used in such cases. This study sought to compare the failure rate of these 2 implants and identify risk factors of artificial implant failure in pediatric patients.
This was a retrospective cohort study examining all pediatric patients who received PEEK or HTR-PMI cranioplasty implants from 2000 to 2013 at a single institution. The authors examined the following variables: age, sex, race, mechanism, surgeon, posttraumatic hydrocephalus, time to cranioplasty, bone gap width, and implant type. The primary outcome of interest was implant failure, defined as subsequent removal and replacement of the implant. These variables were analyzed in a bivariate statistical fashion and in a multivariate logistic regression model for the significant variables.
The authors found that 78.3% (54/69) of implants were successful. The mean patient age was 8.2 years, and a majority of patients were male (73%, 50/69); the mean follow-up for the cohort was 33.3 months. The success rate of the 41 HTR-PMI implants was 78.1%, and the success rate of the 28 PEEK implants was 78.6% (p = 0.96). Implants with a bone gap of > 6 mm were successful in 33.3% of cases, whereas implants with a gap of < 6 mm had a success rate of 82.5% (p = 0.02). In a multivariate model with custom-type implants, previous failed custom cranial implants, time elapsed from previous cranioplasty attempt, and bone gap size, the only independent risk factor for implant failure was a bone gap > 6 mm (odds ratio 8.3, 95% confidence interval 1.2–55.9).
PEEK and HTR-PMI implants appear to be equally successful when custom implantation is required. A bone gap of > 6 mm with a custom implant in children results in significantly higher artificial implant failure.
Paolo Frassanito, Luca Massimi, Massimo Caldarelli, Gianpiero Tamburrini and Concezio Di Rocco
Phoenix, Arizona • March 6–9, 2013