Multidisciplinary Management of Primary Sacral Tumors: A Tertiary Care Center's Experience and Literature Review

Sacral tumors are rare and can be benign or malignant. Their management is multifactorial and is based on the pathology, extent, and local and distant spread. Managing sacral tumors is challenging due to their proximity to visceral and neural structures. Surgical wide excision has been the standard of care for aggressive benign and malignant tumors. Our purpose was to evaluate the outcomes of a multimodal approach to managing primary sacral tumors in Sakra World Hospital, a tertiary spine care center in Bengaluru, India and perform a literature review to determine a workflow pathway. Our study was a retrospective review of patient records and included 15 patients with primary sacral tumors. Eleven surgically treated patients were evaluated clinically and radiologically and underwent biopsy before surgical excision by an all-posterior approach. A multidisciplinary approach that included intraoperative neural monitoring, plastic reconstruction, adjuvant chemotherapy, and radiotherapy was implemented whenever necessary. Sacral root preservation was attempted whenever feasible. Functional outcomes (based on the Visual Analog Scale [VAS] and Biagini scoring system) were analyzed along with disease control, with a minimum of 2 years of follow-up. The mean follow-up was 29±9.8 months. The mean VAS score significantly improved from 7.8±2.6 to 3.7±3.8 (p=0.026). Bowel function showed statistically significant improvement, from a mean score of 0.81±0.47 to 0.63±0.52 (p=0.026) at 2 years of follow-up. The mean pretreatment motor and bladder function scores were 0.53±0.31 and 0.74±0.44, respectively, improving to 0.48±0.33 and 0.68±0.56 at follow-up but without statistical significance. There was no significant loss of function, which is expected in radical sacral resections. In conclusion, primary sacral tumors require a multidisciplinary approach and management for optimal outcomes. A stand-alone posterior approach can be employed to treat most sacral lesions. En-bloc wide resection is the optimal treatment for primary malignant and aggressive benign tumors. Preservation of at least one functional S2 nerve root is imperative to preserve bowel and bladder function.

Conversion of high sacral to midsacral amputation via S-2 nerve preservation during partial S-2 sacrectomy for chordoma

Chordomas of the sacrum require en bloc resection to reduce the risk of recurrence, but this may sacrifice nerves vital to bladder, bowel, and sexual function. High, mid-, and low sacral amputations have been previously classified based on nerve root sacrifice, not bony amputation. Sacrifice of the S-2 nerves or those above results in a high sacral amputation, but preserving the S-2 nerves converts it into a midsacral amputation. Preservation of the S-2 nerves has been shown to improve functional outcome, despite the bony osteotomy being unchanged. Thus, keeping the same bony amputation while preserving the S-2 nerve roots may allow for improved functional outcome while still achieving the same goal of oncological resection. Preservation of the S-2 nerves may be particularly difficult during amputation at the S-2 pedicle or above, and the authors describe their technique for preserving the S-2 nerves during partial sacrectomy at or just above the S-2 pedicle. Four cases of sacral chordoma resections are presented to illustrate the technique.

Surgical techniques for spinopelvic reconstruction following total sacrectomy: a systematic review

PURPOSE

To identify all available reconstruction methods for a total sacrectomy. Secondarily, we aimed to evaluate outcomes based on different interventions.

METHODS

We searched PubMed to identify sacral resections for tumors requiring internal fixation for stabilization. Demographic information, fixation techniques and postoperative outcomes were abstracted.

RESULTS

Twenty-three publications (43 patients) met inclusion criteria from an initial search of 856 (κ 0.93). Mean age was 37 years and follow-up was 33 months. Fixation methods included a combination of spinopelvic fixation (SPF), posterior pelvic ring fixation (PPRF), and/or anterior spinal column fixation (ASCF). For the purposes of analysis, patients were segregated based on whether they received ASCF. Postoperative complications including wound/instrument infections, GI or vascular complications were reported at a higher rate in the non-ASCF group (1.63 complications/patient vs. 0.7 complications/patient). Instrument failure was seen in 5 (16.1 %) out of the 31 patients with reported outcomes. Specifically, 1 out of 8 patients (12.5 %) with ASCF compared with 4 out of 23 patients (17.4 %) without ASCF had hardware failure. At final follow-up, 35 of 39 patients were ambulating.

CONCLUSION

While surgical treatment of primary sacral tumors remains a challenge, there have been advances in reconstruction techniques following total sacrectomy. SPF has shifted from intrapelvic rod and hook constructs to pedicle and iliac screw-rod systems for improved rigidity. PPRF and ASCF have adapted for deficiencies in the posterior ring and anterior column. A trend toward a lower rate of hardware failure emerged in the group utilizing anterior spinal column support. Despite a more involved reconstruction with ASCF, surgical complications such as infection rates and blood loss were lower compared to the group without ASCF. While we cannot definitively say one system is superior to the other, based on the data gleaned from this systematic review, it is our opinion that incorporation of ASCF in reconstructing the spinopelvic junction may lead to improved outcomes. However, most importantly, we recommend that the treating surgeon operate on patients requiring a total sacrectomy based on his or her level of comfort, as these cases can be extremely challenging even among experts.

Computer-assisted modified mid-sacrectomy for en bloc resection of chordoma and preservation of bladder function

A 67-year-old woman presented for evaluation of severe coccygeal pain. The computed tomography scans and magnetic resonance imaging showed an asymmetric midline sacral tumor invading the right lower portion of S2. To preserve both S2 nerve roots and to obtain negative surgical margins, a modified mid-sacrectomy with an aid of a computed navigation system was performed. The sacral tumor was excised en bloc with negative tumor margins. Both S2 nerve roots were preserved and additional reconstruction was not necessary because of minimal resection of the sacroiliac joint. We report a case of a sacral chordoma which was excised en bloc with adequate surgical margins by a computer-assisted modified mid-sacrectomy. The computed navigation system may be a useful tool for tumor targeting and safe osteotomies in sacral tumor surgery via the posterior only approach.

Surgical classification of different types of en bloc resection for primary malignant sacral tumors

PURPOSE

The purpose of the study was to develop a surgical classification system for primary malignant sacral tumors.

METHODS

The sacrum is divided into three regions 1, 2 and 3 by the S1-S2 and S2-S3 junctions. En bloc resections were classified into five types: type I involves regions 1, or 1 and 2, or regions 1, 2 and 3, type II involves regions 2 and 3, and type III involves only region 3. Type IV includes sagittal hemisacrectomy and resection of a portion of the adjacent ilium. Type V includes the sacrum and the fifth lumbar vertebra. 117 patient cases (68 females and 49 males) were reviewed.

RESULTS

There were two perioperative deaths. Of the 35 patients who should have undergone type I resection, local recurrence (LR) occurred in four of the 14 patients who underwent type I resection with free margins without tumor rupture. The other 21 patients underwent piecemeal resection, and LR occurred in 15 (P = 0.013). 35 patients underwent type II resection. Free margin without tumor rupture was accomplished in 26 and LR occurred in 6. Tumor rupture (TR) occurred in the other 9 and LR occurred in seven (Yates' P = 0.012). All 33 patients underwent type III resection with free margins without tumor rupture. LR occurred in five. 11 patients had type IV resection. Free margin without tumor rupture was accomplished in seven and LR occurred in three. TR occurred in the other four, and LR occurred in two (Yates' P = 0.689). One patient underwent type V resection with free margin without tumor rupture and LR occurred. Postoperatively, less than 1/3 needed long-term urethral catheterization. No patients received colostomy for postoperative fecal incontinence. All the patients were able to ambulate.

CONCLUSION

Our classification system and the corresponding surgical approaches are helpful in dealing with primary malignant sacral tumors. Better oncologic results could be expected if free margin without tumor rupture was accomplished.