Shunts: Is Surgical Education Safe?

Failure of Internal Cerebrospinal Fluid Shunt: A Systematic Review and Meta-Analysis of the Overall Prevalence in Adults

OBJECTIVE

Reported rates of failures of internal cerebrospinal fluid shunt (ICSFS) vary greatly from less than 5% to more than 50% and no meta-analysis to assess the overall prevalence has been performed. We estimated the failure rate after ICSFS insertion and searched for associated factors.

METHODS

Six databases were searched from January 1990 to February 2022. Only original articles reporting the rate of adult shunt failure were included. Random-effects meta-analysis with a generalized linear mixed model method and logit transformation was used to compute the overall failure prevalence. Subgroup analysis and meta-regression were implemented to search for associated factors.

RESULTS

Of 1763 identified articles, 46 were selected, comprising 70,859 ICSFS implantations and 13,603 shunt failures, suggesting an accumulated incidence of 19.2%. However, the calculated pooled prevalence value and its 95% confidence interval (CI) were 22.7% (95% CI, 19.8-5.8). The CI of the different estimates did not overlap, indicating a strong heterogeneity confirmed by a high I² of 97.5% (95% CI, 97.1-97.8; P < 0.001; τ² = 0.3). Ninety-five percent prediction interval of shunt failure prevalence ranged from 8.75% to 47.36%. A meta-regression of prevalence of publication found a barely significant decreasing failure rate of about 2% per year (-2.11; 95% CI, -4.02 to -0.2; P = 0.031).

CONCLUSIONS

Despite being a simple neurosurgical procedure, ICSFS insertion has one of the highest risk of complications, with failure prevalence involving more than 1 patient of 5. Nonetheless, all efforts to lower this high level of shunt failure seem to be effective.

Effect of Training on Percutaneous Glycerol Rhizotomy for Trigeminal Neuralgia: A Long-Term, Retrospective Comparison of Staff Neurosurgeon and Trainee Complications and Efficacy

OBJECTIVE

The role of trainee involvement in lesioning procedures for trigeminal neuralgia (TN) has not yet been investigated in reported studies. The objective of the present study was to compare the complications and efficacy of percutaneous glycerol rhizotomy (GR) when performed by staff neurosurgeons and trainees.

METHODS

A retrospective medical record analysis of 165 patients with medically refractory TN who had undergone 293 GR procedures by either a staff attending (n = 156) or trainee (n = 137) from 2007 to 2018 was performed. The data were analyzed with respect to procedure time, fluoroscopy time and radiation exposure, complication rates and outcomes.

RESULTS

No difference was found in procedure duration between the teaching and nonteaching cases and only a nonsignificant trend was found toward a longer fluoroscopy time for the latter. The initial response rates to GR were equal for staff attending (88.7%) and trainee (87.2%) cases (P = 0.708). Similarly, no statistically significant difference (P = 0.48) was found between the median time to recurrence for the staff attending cases (1.6 ± 0.3 years) compared with that of the trainee cases (1.7 ± 0.3 years). The overall incidence of complications was low (7.5%). The occurrence of facial hypoesthesia correlated with the amount of glycerol injected (P < 0.01).

CONCLUSIONS

GR for the treatment of TN can safely be performed by senior residents and fellows under supervision.

Safety of resident training in the microsurgical resection of intracranial tumors: Data from a prospective registry of complications and outcome

The aim of the present study was to assess the safety of microsurgical resection of intracranial tumors performed by supervised neurosurgical residents. We analyzed prospectively collected data from our institutional patient registry and dichotomized between procedures performed by supervised neurosurgery residents (defined as teaching procedures) or board-certified faculty neurosurgeons (defined as non-teaching procedures). The primary endpoint was morbidity at discharge, defined as a postoperative decrease of ≥10 points on the Karnofsky Performance Scale (KPS). Secondary endpoints included 3-month (M3) morbidity, mortality, the in-hospital complication rate, and complication type and severity. Of 1,446 consecutive procedures, 221 (15.3%) were teaching procedures. Patients in the teaching group were as likely as patients in the non-teaching group to experience discharge morbidity in both uni- (OR 0.85, 95%CI 0.60-1.22, p = 0.391) and multivariate analysis (adjusted OR 1.08, 95%CI 0.74-1.58, p = 0.680). The results were consistent at time of the M3 follow-up and in subgroup analyses. In-hospital mortality was equally low (0.24 vs. 0%, p = 0.461) and the likelihood (p = 0.499), type (p = 0.581) and severity of complications (p = 0.373) were similar. These results suggest that microsurgical resection of carefully selected intracranial tumors can be performed safely by supervised neurosurgical residents without increasing the risk of morbidity, mortality or perioperative complications. Appropriate allocation of operations according to case complexity and the resident's experience level, however, appears essential.

Burr hole trepanation for chronic subdural hematomas: is surgical education safe?

BACKGROUND

There is a paucity of data concerning the safety and efficacy of surgical education for neurosurgical residents in the evacuation of chronic subdural hematomas (cSDH) by burr hole trepanation.

METHODS

This is a retrospective analysis of prospectively collected data on consecutive patients receiving burr hole trepanation for uni- or bilateral cSDH. Patients operated by a supervised neurosurgery resident (teaching cases) were compared to patients operated by a board-certified faculty neurosurgeon (BCFN; non-teaching cases). The primary endpoint was surgical revision for any reason until the last follow-up. The secondary endpoint was occurrence of any complication until the last follow-up. Clinical status, type of complications, mortality, length of surgery (LOS), and hospitalization (LOH) were tertiary endpoints.

RESULTS

A total of n = 253 cases were analyzed, of which n = 217 (85.8%) were teaching and n = 36 (14.2%) non-teaching cases. The study groups were balanced in terms of age, sex, surgical risk (ASA score), and preoperative status (Karnofsky Performance Scale (KPS), modified Rankin Scale (mRS), National Institute of Health Stroke Scale (NIHSS)). The cohort was followed for a mean of 242 days (standard deviation 302). In multivariate analysis, teaching cases were as likely as non-teaching cases to require revision surgery (OR 0.65, 95% CI 0.27-1.59; p = 0.348) as well as to experience any complication until the last follow-up (OR 0.79, 95% CI 0.37-1.67; p = 0.532). Mean LOS was about 10 min longer in teaching cases (53.0 ± 26.1 min vs. 43.5 ± 17.8 min; p = 0.036), but LOH was similar. There were no group differences in clinical status, mortality and type of complication at discharge, and the last follow-up.

CONCLUSIONS

Burr hole trepanation for cSDH can be safely performed by supervised neurosurgical residents enrolled in a structured training program, without increasing the risk for revision surgery, perioperative complications, or worse outcome.