Efficacy of neuroendoscopic-assisted surgery in the management of symptomatic sacral perineural (Tarlov) cysts: a technical report

Introduction

The Tarlov cysts are pathological enlargements of the cerebrospinal fluid spaces between the endoneurium and perineurium, which can cause intolerable sciatic pain, motor impairment of lower limbs, and bladder/bowel dysfunction. Currently, the treatment results are unsatisfactory due to the low cure rates and extensive surgical trauma. Thus, there is an ongoing exploration of surgical techniques for Tarlov treatment. In the current study, we present a novel neuroendoscopic-assisted technique that combines the fenestration, leakage sealing, and tamponade of the Tarlov cyst.

Methods

Between January 2020 and December 2021, a total of 32 Tarlov patients were enrolled and received neuroendoscopic-assisted surgery. Their pre- and post-surgical Visual Analogue Scale (VAS) scores, major complaints, and MR imaging were recorded for comparison.

Results

27 of 32 patients (84.4%) patients demonstrated immediate pain relief as their VAS scores decreased from 5.6 ± 1.5 to 2.5 ± 1.1 (p < 0.01) on the first day after surgery. At the 3-month follow-up, the patients' average VAS score continued to decrease (1.94 ± 0.8). Meanwhile, saddle paresthesia, urinary incontinence, and constipation were relieved in 6 (50%), 4 (80%), and 5 (41.7%), respectively, according to patients self-report. No surgical-related complication was observed in any of the cases.

Discussion

We conclude that neuroendoscopic-assisted surgery is an effective surgical method for symptomatic Tarlov cysts with minimized complications.

Choriocapillaris Ischemia at the Leakage Point of Patients With Acute Central Serous Chorioretinopathy

Purpose: We aimed to determine ischemia of the choriocapillaris at the leakage point of patients with acute central serous chorioretinopathy (CSC) by optical coherence tomographic angiography (OCTA). Methods: A retrospective study of 38 eyes of 38 acute CSC patients with spontaneous complete resolution of subretinal fluid (SRF) was conducted and patients were followed for 3 months. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed at baseline. Best corrected visual acuity (BCVA) and OCTA were collected at baseline and at follow-up visits. An age- and refractive error-matched control group consisted of 40 eyes of 40 healthy people. Results: The BCVA of patients significantly improved at 1 and 3 months. At baseline, all eyes showed a decreased choriocapillaris vessel density. The mean vessel density of superficial choroid (VDSC) at the leakage point area was 44.18 ± 9.27, which increased to 54.31 ± 9.70 at 1 month (p < 0.001) and to 55.19 ± 6.46 at 3 months (p < 0.001). The mean vessel density ratio was 0.90 ± 0.16 at baseline, which increased to 0.96 ± 0.15 at 1 month (p = 0.037) and to 0.97 ± 0.08 at 3 months (p = 0.016). The highest VDSC of patients was lower than that of normal control (p < 0.001). Conclusions: The VDSC at the leakage point of acute CSC patients was significantly thinner and regularly increased with the recovery process, which suggested that ischemia might be one of the initiating factors in the pathogenesis of acute CSC.

Retinal Pigment Epithelium Reflectivity at Leakage Site on Spectral-Domain Optical Coherence Tomography in Acute Central Serous Chorioretinopathy

PURPOSE

To study the reflectivity of the retinal pigment epithelium (RPE) at the leakage site in acute central serous chorioretinopathy (CSC).

METHODS

Twenty-nine patients (24 males and 5 females, mean age 46.1 ± 11.0 years) were included. The mean relative RPE reflectivity and the difference between the maximum and minimum relative RPE reflectivity at the leakage site and control site were measured on cross-sectional optical coherence tomography (OCT) scans. In eyes with pinpoint leakage, cross-sectional OCT scans and corresponding reflectivity profile plots were reviewed by a masked grader for the presence of visible RPE defects and focal depression of relative RPE reflectivity at the leak.

RESULTS

Twenty-one (61.7%) and 13 (38.2%) leaks showed pinpoint and diffuse leakage, respectively. The mean relative RPE reflectivity at the leakage site was statistically significantly higher than that of the control site (0.82 ± 0.09 and 0.79 ± 0.12, respectively, p=0.03) in eyes with pinpoint leakage as well as in eyes with diffuse leakage (0.81 ± 0.10 and 0.74 ± 0.13, respectively, p=0.01). The difference of relative RPE reflectivity was statistically significantly higher at the leakage site compared to control site (0.56 ± 0.20 and 0.41 ± 0.06, respectively, p=0.002) in eyes with pinpoint leakage, but not in eyes with diffuse leakage (0.46 ± 0.12 and 0.40 ± 0.07, respectively, p=0.16). On cross-sectional OCT scans visible RPE defects at pinpoint leakage were found in 10 out of 21 (47.6%) cases. Focal depressions of RPE reflectivity corresponding to presumed RPE defects were found in 18 out of 21 (85.7%) cases.

CONCLUSION

Leakage in acute CSC is associated with significant local increase of RPE reflectivity.

Choroidal Changes at the Leakage Site in Acute Central Serous Chorioretinopathy

Purpose: To analyze the choroidal vasculature at leak site and at the center of macula in acute central serous chorioretinopathy (CSCR) and to evaluate their co-relation with eccentricity of leak site. Methods: This retrospective study involved optical coherence tomography analysis of 27 eyes with acute CSCR. Relationship between macular thickness; large choroidal vessels diameter; baseline subfoveal and leakage point choroidal thickness, and eccentricity of leak point was evaluated. Results: A larger choroidal vessel caliber/choroidal thickness ratio was found at the leak site than fovea in both active (p = 0.0001) and resolved (p = 0.003) CSCR. Ratio at leakage point decreased after resolution of SRF (p = 0.004). Choroidal thickness at subfovea (p = 0.004), leakage point (p = 0.02); and difference between central and leakage point choroidal thickness (r = 0.6, p = 0.009) were significantly associated with the eccentricity of leakage point. Conclusion: Subfoveal and leak site choroidal profile could predict the eccentricity of leakage in CSCR.

[Optical coherence tomography in diagnostics and treatment of central serous chorioretinopathy]

PURPOSE

To identify the signs of leakage points in central serous chorioretinopathy (CSC) patients using optical coherence tomography (OCT) allowing focal laser photocoagulation (FLP) to be performed without the need for fluorescein angiography (FA) in their treatment; to evaluate the effectiveness and safety of the approach.

MATERIAL AND METHODS

The retrospective part of the study included 54 patients (54 eyes) with distinctive signs of CSC further confirmed by the presence of a leakage point as could be seen with FA. The number of pigment epithelial detachments (PED), the thickness of the photoreceptor outer segments (PROS) layer, maximum horizontal length of the photoreceptor thinning area, and morphological changes in the outer retinal layers were evaluated with OCT. Using FA for each leakage point, its localization and coincidence with PED were evaluated in retro-mode confocal scanning laser ophthalmoscopy and OCT images, respectively. The prospective part of the study included 11 CSC patients (11 eyes) who underwent en face OCT-guided FLP of the leakage point with NAVILAS 532 system.

RESULTS

The leakage points were found to coincide with PED in 50 eyes (92.6%). Mean distance from the superior border of the retinal detachment area to the leakage point was 28.8±14.1% of the retinal detachment height. In 90.3% of cases the PROS layer in the area above the PED was thinner (23.3±7.8 µm) compared to the area outside the leakage point (64.0±9.4 µm) (p<0.001). FA-free OCT-guided FLP required in average 3.3±0.5 laser burns per leakage point. Complete resolution of subretinal fluid occurred in all treated eyes within 7.5±1.0 weeks after the surgery, and no adverse events were observed.

CONCLUSION

Coincidence of PED in the superior half of the area of retinal detachment with thinning of the PROS layer as seen on OCT can be considered a reliable sign of the leakage point. The FA-free FLP based on OCT appears to be an effective and safe procedure for the treatment of CSC.