Nerve Root Sparing En Bloc Resection of Sacral Chondrosarcoma: Technical Note and Review of the Literature

BACKGROUND Total en bloc sacrectomy provides the best long-term local control for large primary bony sacral tumors, but often requires lumbosacral nerve root sacrifice leading to loss of ambulation and/or bowel, bladder, and/or sexual dysfunction. Nerve-sparing techniques may be an option for some patients that avoid these outcomes and accordingly improve postoperative quality of life. OBJECTIVE To describe the technique for a posterior-only en bloc hemisacrectomy with maximal nerve root preservation and to summarize the available literature. METHODS A 38-yr-old woman with a 7.7 × 5.4 × 4.5 cm biopsy-proven grade 2 chondrosarcoma involving the left L5-S2 posterior elements underwent a posterior-only left hemisacrectomy tri-rod L3-pelvis fusion. A systematic review of the English literature was also conducted to identify other descriptions of high sacrectomy with distal sacral nerve root preservation. RESULTS Computer-aided navigation facilitated an extracapsular resection that allowed preservation of the left-sided L5 and S3-Co roots. Negative margins were achieved and postoperatively the patient retained ambulation and good bowel/bladder function. Imaging at 9-mo follow-up showed no evidence of recurrence. The systematic review identified 4 prior publications describing 6 total patients who underwent nerve-sparing sacral resection. Enneking-appropriate resection was only obtained in 1 case though. CONCLUSION Here we describe a technique for distal sacral nerve root preservation during en bloc hemisacrectomy for a primary sacral tumor. Few prior descriptions exist, and the present technique may help to reduce the neurological morbidity of sacral tumor surgery.

A systematic comparative outcome analysis of surgical versus percutaneous techniques in the management of symptomatic sacral perineural (Tarlov) cysts: a meta-analysis

OBJECTIVESymptomatic perineural or Tarlov cysts (TCs) are a rare cause of chronic low-back pain. Given the rarity of the disease, there is no literature consensus regarding the optimal management of these cysts.METHODSThe authors conducted a systematic comparative outcome analysis of symptomatic TCs treated with surgery (group A, 32 studies, n = 333) or percutaneous interventions (group B, 6 studies, n = 417) analyzing the demographic characteristics, baseline characteristics of the cysts, clinical presentations, types of interventions, complication rates, and the recurrence rate in both treatment groups. The literature search was performed using the PubMed, MEDLINE, Cochrane, and Ovid databases up to 2018. The MeSH search terms used were “Tarlov cyst,” “sacral perineural cyst,” “sacral nerve root cyst,” “meningeal cyst of the sacral spine,” “extra meningeal cyst with spinal nerve root fibers,” “spinal extradural arachnoid pouch,” and “cyst of the sacral nerve root sheath.” The authors used statistical tests for two proportions using the “N-1” chi-square test with the free version of MedCalc for Windows for comparison among the groups.RESULTSOverall symptomatic improvement was reported in 83.5% of patients in both groups; however, exacerbation of preprocedural symptoms was significantly higher in group B than group A (10.1% vs 3.3%, p = 0.0003). The overall complication rates in the surgical and nonsurgical groups were 21% and 12.47%, respectively. Transient sciatica was the most common complication in both groups (17% vs 8%, respectively; p = 0.017). The incidence of cyst recurrence was much lower in group A than group B (8% vs 20%, p = 0.0018). The mean follow-up duration for the surgical group was 38 ± 29 months (25 studies, n = 279), while that for the nonsurgical group was 15 ± 12 months (4 studies, n = 290) (p < 0.0001).CONCLUSIONSThe authors noted that although the surgical interventions were associated with higher postprocedural complication rates, long-term efficacy and success in terms of cyst resolution were superior following surgery compared to percutaneous procedures in the management of symptomatic TCs. There was no difference in symptom recurrence with either of the techniques.