Circumferential sulcus-guided resection technique for improved outcomes of low-grade gliomas

OBJECTIVE Many neurosurgeons resect nonenhancing low-grade gliomas (LGGs) by using an inside-out piecemeal resection (PMR) technique. At the authors’ institution they have increasingly used a circumferential, perilesional, sulcus-guided resection (SGR) technique. This technique has not been well described and there are limited data on its effectiveness. The authors describe the SGR technique and assess the extent to which SGR correlates with extent of resection and neurological outcome. METHODS The authors identified all patients with newly diagnosed LGGs who underwent resection at their institution over a 22-year period. Demographics, presenting symptoms, intraoperative data, method of resection (SGR or PMR), volumetric imaging data, and postoperative outcomes were obtained. Univariate analyses used ANOVA and Fisher’s exact test. Multivariate analyses were performed using multivariate logistic regression. RESULTS Newly diagnosed LGGs were resected in 519 patients, 208 (40%) using an SGR technique and 311 (60%) using a PMR technique. The median extent of resection in the SGR group was 84%, compared with 77% in the PMR group (p = 0.019). In multivariate analysis, SGR was independently associated with a higher rate of complete (100%) resection (27% vs 18%) (OR 1.7, 95% CI 1.1–2.6; p = 0.03). SGR was also associated with a statistical trend toward lower rates of postoperative neurological complications (11% vs 16%, p = 0.09). A subset analysis of tumors located specifically in eloquent brain demonstrated SGR to be as safe as PMR. CONCLUSIONS The authors describe the SGR technique used to resect LGGs and show that SGR is independently associated with statistically significantly higher rates of complete resection, without an increase in neurological complications, than with PMR. SGR technique should be considered when resecting LGGs.

Endoscopic submucosal dissection for colorectal neoplasia: outcomes and predictors of recurrence

Background and study aims The role of endoscopic submucosal dissection (ESD) for colorectal lesions in Western communities is unclear and its adoption is still limited. The aim of this study is to assess the long-term outcomes of a large cohort of patients treated with colorectal ESD in a tertiary Western center. Patients and methods A retrospective analysis was conducted on patients treated by ESD for superficial colorectal lesions between February 2011 and November 2019. The primary outcome was the recurrence rate. Secondary outcomes were en-bloc and R0 resection rates, procedural time, adverse events (AEs), and need for surgery. The curative resection rate was assessed for submucosal invasive lesions. Results A total of 327 consecutive patients, median age 69 years (IQR 60–76); 201 men (61.5 %) were included in the analysis. Of the lesions, 90.8 % were resected in an en-bloc fashion. The rate of R0 resection was 83.1 % (217/261) and 44.0 % (29/66) for standard and hybrid ESD techniques, respectively. Submucosal invasion and piecemeal resection independently predicted R1 resections. A total of 18(5.5 %) intra-procedural AEs (perforation:11, bleeding:7) and 12(3.7 %) post-procedural AEs occurred (perforation:2, bleeding: 10). Eighteen adenoma recurrences per 1,000 person-years (15cases, 5.6 %) were detected after a median follow-up time of 36 months. All recurrences were detected within 12 months. No carcinoma recurrences were observed. R1 resection status and intra-procedural AEs independently predicted recurrences with seven vs 150 recurrences per 1,000 person-years in the R0 vs R1 group, respectively. Conclusions Colorectal ESD is a safe and effective option for managing superficial colorectal neoplasia in a Western setting, with short and long-terms outcomes comparable to Eastern studies. En-bloc R0 resection and absence of intra-procedural AEs are associated with reduced risk of recurrence.

MET-6 Neoadjuvant fractionated stereotactic radiotherapy followed by piecemeal resection for metastatic brain tumor

BACKGROUND: Large brain metastases which require resection are treated with surgery followed by whole brain radiation therapy or postoperative stereotactic radiosurgery (SRS). Recently a novel strategy using neoadjuvant stereotactic radiosurgery (Na-SRS) followed by surgery was reported, demonstrating lower rates of postoperative leptomeningeal dissemination (LMD) and symptomatic radiation necrosis (RN). We treated with neoadjuvant fractionated stereotactic radiotherapy (Na-fSRT) followed by surgery for large brain metastasis with piecemeal resection. METHODS: Twelve patients received Na-fSRT followed by surgery between July 2019 and April 2021. Na-fSRT dose was based on lesion size and was standard dosing. Surgery generally followed within 7 days after radiotherapy. RESULTS: The mean age was 68 years (51–79). Sixteen men and five women. Mean follow-up period was 8.5 months (1–24.9). Primary were lung; 10 (NSCLC; 9, SCLC (recurrence); 1), esophagus; 3, colon; 2, melanoma; 2, kidney; 2 (recurrence1), uterus body; 1, and liver; 1. The median maximum tumor diameter was 3.6 cm (2.6–4.9). Median PTV, GTV volume were 21.7ml, 15.5ml, respectively. The median fSRT dose was 30Gy/5fr, and the median time from fSRT to surgery was 4 days (1–7). As preoperative adverse event, intracranial hypertension and partial seizure grade 2 (CTCAE ver.5) were occurred, but controlled with steroid and osmotic diuretics and anticonvulsant. Grade 3 and more adverse events were not occurred. Gross total removal was performed in 95.2%. Event cumulative incidence as follows: cavity local recurrence 4.8% (subtotal removal case); distant brain failure 33%; LMD 4.8%; and symptomatic RN 0%. The median intracranial progression free survival was 7 months, and median overall survival was 8.4 months. CONCLUSIONS: Na-fSRT followed by piecemeal resection is safety and feasible, and may have therapeutic value for deep large brain metastasis and eloquent lesion. Further prospective investigations in multi-institutional settings are warranted.

Neoadjuvant fractionated stereotactic radiotherapy followed by piecemeal resection of brain metastasis: a case series of 20 patients

Background The safety and effectiveness of neoadjuvant fractionated stereotactic radiotherapy (FSRT) before piecemeal resection of brain metastasis (BM) remains unknown. Methods We retrospectively reviewed 20 consecutive patients with BM who underwent neoadjuvant FSRT followed by piecemeal resection between July 2019 and March 2021. The prescribed dose regimens were as follows: 30 Gy (n = 11) or 35 Gy (n = 9) in five fractions. Results The mean follow-up duration was 7.8 months (range 2.2–22.3). The median age was 67 years (range 51–79). Fourteen patients were male. All patients were symptomatic. All tumors were located in the supratentorial compartment. The median maximum diameter and volume were 3.7 cm (range 2.6–4.9) and 17.6 cm3 (range 5.6–49.7), respectively. The median time from the end of FSRT to resection was 4 days (range 1–7). Nausea (CTCAE Grade 2) occurred in one patient and simple partial seizures (Grade 2) in two patients during radiation therapy. Gross total removal was performed in seventeen patients and sub-total removal in three patients. Postoperative complications were deterioration of paresis in two patients. Local recurrence was found in one patient (5.0%) who underwent sub-total resection at 2 months after craniotomy. Distant recurrence was found in six patients (30.0%) at a median of 6.9 months. Leptomeningeal disease recurrence was found in one patient (5.0%) at 3 months. No radiation necrosis developed. Conclusions Neoadjuvant FSRT appears to be a safe and effective approach for patients with BM requiring piecemeal resection. A multi-institutional prospective trial is needed.

Leptomeningeal disease in neurosurgical brain metastases patients: a systematic review and meta-analysis

Background Leptomeningeal disease (LMD) is a complication distinguished by progression of metastatic disease into the leptomeninges and subsequent spread via cerebrospinal fluid (CSF). Although treatments for LMD exist, it is considered fatal with a median survival of two to four months. A broader overview of the risk factors that increase the brain metastasis (BM) patient’s risk of LMD is needed. This meta-analysis aimed to systematically review and quantitatively assess risk factors for LMD after surgical resection for BM. Methods A systematic literature search was performed on 7 May 2021. Pooled effect sizes were calculated using a random-effects model for variables reported by three or more studies. Results Among 503 studies, thirteen studies met the inclusion criteria with a total surgical sample size of 2105 patients, of which 386 patients developed LMD. The median incidence of LMD across included studies was 16.1%. Eighteen unique risk factors were reported as significantly associated with LMD occurrence, including but not limited to: larger tumor size, infratentorial BM location, proximity of BM to cerebrospinal fluid spaces, ventricle violation during surgery, subtotal or piecemeal resection, and postoperative stereotactic radiosurgery. Pooled results demonstrated that breast cancer as the primary tumor location (HR = 2.73, 95% CI: 2.12 -3.52) and multiple BMs (HR = 1.37, 95% CI: 1.18-1.58) were significantly associated with a higher risk of LMD occurrence. Conclusion Breast cancer origin and multiple BMs increase the risk of LMD occurrence after neurosurgery. Several other risk factors which might play a role in LMD development were also identified.

Endoscopic resection outcomes and predictors of failed en bloc endoscopic mucosal resection of colorectal polyps ≤ 20 mm among advanced endoscopy trainees

Background and study aims En bloc endoscopic mucosal resection (EMR) is preferred over piecemeal resection for polyps ≤ 20 mm. Data on colorectal EMR training are limited. We aimed to evaluate the en bloc EMR rate of polyps ≤ 20 mm among advanced endoscopy trainees and to identify predictors of failed en bloc EMR. Methods This was a multicenter prospective study evaluating trainee performance in EMR during advanced endoscopy fellowship. A logistic regression model was used to identify the number of procedures and lesion cut-off size associated with an en bloc EMR rate of ≥ 80 %. Multivariate analysis was performed to identify predictors of failed en bloc EMR. Results Six trainees from six centers performed 189 colorectal EMRs, of which 104 (55 %) were for polyps ≤ 20 mm. Of these, 57.7 % (60/104) were resected en bloc. Trainees with ≥ 30 EMRs (OR 6.80; 95 % CI: 2.80–16.50; P = 0.00001) and lesions ≤ 17 mm (OR 4.56;95 CI:1.23–16.88; P = 0.02) were more likely to be associated with an en bloc EMR rate of ≥ 80 %. Independent predictors of failed en bloc EMR on multivariate analysis included: larger polyp size (OR:6.83;95 % CI:2.55–18.4; P = 0.0001), right colon location (OR:7.15; 95 % CI:1.31–38.9; P = 0.02), increased procedural difficulty (OR 2.99; 95 % CI:1.13–7.91; P = 0.03), and having performed < 30 EMRs (OR: 4.87; 95 %CI: 1.05–22.61; P = 0.04). Conclusions In this pilot study, we demonstrated that a relatively low proportion of trainees achieved en bloc EMR for polyps ≤ 20 mm and identified procedure volume and lesion size thresholds for successful en bloc EMR and independent predictors for failed en bloc resection. These preliminary results support the need for future efforts to define EMR procedure competence thresholds during training.

A Surveillance Endoscopy Strategy Based on Local Recurrence Rates after Colorectal Endoscopic Submucosal Dissection

Backgrounds: It is not clear when and how frequently surveillance endoscopy should be performed after colorectal endoscopic submucosal dissection (ESD). We aimed to suggest a surveillance endoscopy strategy by investigating the cumulative local recurrence rates and identifying risk factors for local recurrence after colorectal ESD. Methods: We reviewed the medical records of 770 patients who underwent colorectal ESD for 778 lesions at our institution from 2005 to 2016. We investigated the cumulative local recurrence rates and risk factors for local recurrence. Results: Local recurrence developed in 12 (1.5%) of 778 lesions during the follow-up period of 37.4 ± 31.7 months. The one-, three-, and five-year cumulative local recurrence rates were 0.4%, 1.7%, and 2.2%, respectively. The risk factors for local recurrence were piecemeal resection (odds ratio (OR) 3.948, 95% confidence interval (CI) 1.164–13.385; p = 0.028) and histological incomplete resection (OR 8.713, 95% CI 2.588–29.334; p < 0.001). Local recurrence tended to develop frequently after ESD of early cancers. Conclusions: Short-term surveillance endoscopy should be recommended after piecemeal ESD, histological incomplete resection, and ESD of early colorectal cancers. Surveillance endoscopy with longer intervals can be suggested after en bloc ESD with the histological complete resection of benign colorectal tumors.

Cold snare polypectomy without submucosal injection: safety and efficacy in 615 large serrated lesions

Background and study aim Cold resection is becoming the standard of care for the resection of nonpedunculated colon lesions up to 10 mm in diameter. Sessile serrated adenomas/polyps (SSA/Ps), including those ≥ 10 mm, present various characteristics that make them ideal candidates for cold snare polypectomy (CSP). Patients and methods A prospectively maintained database was searched retrospectively for consecutive patients with lesions ≥ 10 mm resected between March 2013 and March 2018. During that period, all SSA/P-appearing lesions were resected using CSP without submucosal injection, except for lesions with endoscopic suspicion of dysplasia or submucosal invasion. Patients with a pathological diagnosis of SSA/P were included in the analysis. Adverse events were recorded up to 21 days following colonoscopy. Results 615 SSA/Ps ≥ 10 mm were resected during 452 colonoscopy procedures in 379 patients (mean age 54.1 years; standard deviation [SD] 11.9 years). Mean polyp size was 13.7 (SD 5.2) mm; 122 lesions (19.8 %) were ≥ 20 mm and 479 lesions (77.9 %) underwent piecemeal resection. Immediate adverse events included persistent abdominal pain that resolved spontaneously within 2 hours in three patients (0.8 %; 95 % confidence interval [CI] 0.2 %–2.3 %). One patient with persistent intraprocedural bleeding was successfully treated with a hemostatic clip. No late adverse events were detected. Surveillance colonoscopy was performed in 293 patients (77.3 %) at 23.4 (SD 11.6) months following index colonoscopy; residual/recurrent lesions were diagnosed in 23 patients (7.8 %; 95 %CI 5.0 %–11.6 %). Conclusion CSP without submucosal injection appeared to be safe and effective for the resection of large SSA/Ps.

The surgical challenge of ossified ventrolateral spinal meningiomas: tricks and pearls for managing large ossified meningiomas of the thoracic spine

The authors present an illustrative technical note on microsurgical resection of ventrolateral completely ossified spinal meningiomas (OSMs) and a literature review of the surgical management of calcified spinal meningiomas or OSMs. These tumors are surgically demanding due to their solid consistency, especially when in a ventrolateral location with dislocation of the spinal cord. A challenging case with significant thoracic cord compression and displacement is described. Due to the firm consistency and the ventrolateral localization of the meningioma, a piecemeal resection was necessary. This could have resulted in a free-floating tumor remnant adherent to the spinal cord, impeding safe tumor resection. To avoid such a remnant, an anchoring burr hole was drilled at the border between the spinal cord and the adamantine tumor mass. Then, a microdissector was placed within the anchoring burr hole and the tumor was gently pulled laterally while drilling away the medial parts of the ossified tumor. This procedure was repeated until separation of the tumor from the spinal cord was possible and a gross-total resection (Simpson grade II) was manageable. Throughout the procedure, continuous intraoperative neurophysiological monitoring was performed.