Diagnostic Accuracy and Field for Improvement of Frameless Stereotactic Brain Biopsy: A Focus on Nondiagnostic Cases.

BACKGROUND: The diagnostic accuracy of frameless stereotactic brain biopsy has been reported, but there is limited literature focusing on the reasons for nondiagnostic cases. In this study, we evaluate the diagnostic accuracy of frameless stereotactic brain biopsy, compare it with the current international standard, and review the field for improvement. METHODS: This is a retrospective analysis of consecutive, prospectively collected frameless stereotactic brain biopsies from 2007 to 2020. We evaluated the diagnostic accuracy of the frameless stereotactic brain biopsies using defined criteria. The biopsy result was classified as conclusive, inconclusive, or negative, based on the pathologic, radiologic, and clinical diagnosis concordance. For inconclusive or negative results, we further evaluated the preoperative planning and postoperative imaging to review the errors. A literature review for the diagnostic accuracy of frameless stereotactic biopsy was performed for the validity of our results. RESULTS: There were 106 patients with 109 biopsies performed from 2007 to 2020. The conclusive diagnosis was reached in 103 (94.5%) procedures. An inconclusive diagnosis was noted in four (3.7%) procedures and the biopsy was negative in two (1.9%) procedures. Symptomatic hemorrhage occurred in one patient (0.9%). There was no mortality in our series. Registration error (RE) and inaccurate targeting occurred in three trigonal lesions (2.8%), sampling of the nonrepresentative part of the lesion occurred in two cases (1.8%), and one biopsy (0.9%) for lymphoma was negative due to steroid treatment. The literature review suggested that our diagnostic accuracy was comparable with the published literature. CONCLUSION: The frameless stereotactic biopsy is a safe procedure with high diagnostic accuracy only if meticulous preoperative planning and careful intraoperative registration is performed. The common pitfalls precluding a conclusive diagnosis are RE and biopsies at nonrepresentative sites.

Long-term outcomes of ruptured cerebral arteriovenous malformations in the paediatric population: A retrospective review in a regional hospital in Hong Kong.

The objective of the study is to evaluate the management outcomes of ruptured cerebral arteriovenous malformations (bAVMs) in the paediatric population in a regional hospital in Hong Kong. We performed a retrospective review between 1 January 1999 and 31 December 2017 for ruptured bAVM in a regional neurosurgical centre in Hong Kong. All other vascular pathologies and unruptured cases were excluded. Thirty-three eligible patients were included for analysis. The median age at presentation was 12 (3-18), with a slight male preponderance. Presenting complaints included headache (60.6%), motor deficits (24.2%), and seizure (6.1%). Glasgow coma scale (GCS) on presentation (median, IQR) was 15 (13-15). bAVMs were lobar in 57.6%, infratentorial in 27.3%, and basal ganglia in 9.1%. Follow-up was 101 ±â€¯61 months and ranged from 24 to 229 months. 12 (36.4%) patients underwent emergency haematoma evacuation with or without bAVM excision because of neurological deterioration in the acute phase. 7 (21.2%) patients underwent interval excision and 11(33.3%) patients underwent stereotactic radiosurgery (SRS). There was no residual bAVM and no Clavien-Dindo complications greater than grade II in interval surgery group. Those who underwent SRS had a significantly higher Spetzler-Martin grade; bAVM obliteration was achieved at 73.3%, without any major symptomatic post-radiosurgery complications. There was 1 (3%) mortality and 30 (90.9%) patients recovered well with minor non-disabling deficits (GOS 5). For paediatric patients with ruptured bAVM, a satisfactory management outcome can be achieved with careful patient selection for surgery and radiosurgery.

Blessing or burden? Long-term maintenance, complications and clinical outcome of intrathecal baclofen pumps.

AIM: The intrathecal baclofen pump is an effective treatment for spasticity. However, long-term results have reported patients' dissatisfaction and perception of disability. Potential causes include a frequent need for baclofen pump refill and risks of complications. The aim of the present study was to evaluate the long-term maintenance, complications and clinical outcome of intrathecal baclofen pumps. PATIENTS AND METHODS: We conducted a 16-year retrospective cohort study of patients with spasticity treated with an intrathecal baclofen pump at a university hospital from 2000 to 2016. The primary outcome was the rate of infection per puncture for baclofen pump refill. Secondary outcomes included the incidence of other complications, such as running out of baclofen causing symptomatic withdrawal symptoms, pump mechanical failure, pump battery end of life and the need for pump replacement. The clinical outcome was assessed by the Modified Ashworth Scale (mAS). RESULTS: In total, 340 follow-up episodes with pump refill procedures were recorded. The average interval between each pump refill was 57.3 days (±15.4 days). The average duration of admission for each pump refill was 4 h and 49 min (from 2 h 23 min to 10 h). There were two events with established infection after puncture for the refill, giving rise to an infection rate per puncture of 0.6 percent (2/340).For the long-term clinical outcome, at an average follow-up period of 7.6 years, the postoperative mAS for spasticity was 2.0 ± 0.756, which was significantly better than the preoperative mAS at 3.75 ± 0.462 (P = 0.001). CONCLUSION: Long-term aftercare with baclofen pump refill was safe, with an infection rate of 0.6 per cent per puncture for each refill. Long-term intrathecal baclofen pump was effective in the treatment of spasticity with persistent significant improvement in the spasticity scale.

Awake craniotomy for excision of arteriovenous malformations? A qualitative comparison study with stereotactic radiosurgery.

Treatment of arteriovenous malformations (AVM) located at the eloquent area has been a challenge. Awake brain mapping allows identification of a non-eloquent gyrus for intervention and can potentially facilitate resection with preservation of functions. An alternative treatment option is stereotactic radiosurgery (SRS). The objective of this study was to perform a qualitative comparison of the treatment outcome of awake AVM excision versus SRS. We conducted a 13-year retrospective review of AVM excision under awake craniotomy performed at Prince of Wales Hospital, Hong Kong, from 2003 to 2016. Patients' presentation, Spetzler-Martin (SM) grading, rate of obliteration and complication were reviewed and analyzed with the modified radiosurgery-based AVM score (RS score). Six patients had excision of AVM under awake mapping during this period of time. Two were SM Grade II and four were SM Grade III. Five located at the peri-rolandic region while one at the temporal language area. None had failed mapping. Five out of six achieved complete obliteration (83.3%). Qualitative comparative analysis had revealed better treatment outcome with awake AVM excision as compared to SRS with the obliteration rate of 100% versus 96% for RS score ≤1.00, 100% versus 78% for RS score 1.01-1.50, and 66% versus 50% for RS score >2.00 respectively. In conclusion, awake mapping and excision of AVMs at the eloquent area is feasible. Qualitative comparative analysis had revealed higher obliteration rate with awake AVM excision as compared to SRS.