Presacral retroperitoneal approach to axial lumbar interbody fusion: a new, minimally invasive technique at L5-S1: Clinical outcomes, complications, and fusion rates in 50 patients at 1-year follow-up

Radiologic Assessment of Interbody Fusion: A Systematic Review on the Use, Reliability, and Accuracy of Current Fusion Criteria

BACKGROUND

Lumbar interbody fusion (IF) is a common procedure to fuse the anterior spine. However, a lack of consensus on image-based fusion assessment limits the validity and comparison of IF studies. This systematic review aims to (1) report on IF assessment strategies and definitions and (2) summarize available literature on the diagnostic reliability and accuracy of these assessments.

METHODS

Two searches were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Search 1 identified studies on adult lumbar IF that provided a detailed description of image-based fusion assessment. Search 2 analyzed studies on the reliability of specific fusion criteria/classifications and the accuracy assessed with surgical exploration.

RESULTS

A total of 442 studies were included for search 1 and 8 studies for search 2. Fusion assessment throughout the literature was highly variable. Eighteen definitions and more than 250 unique fusion assessment methods were identified. The criteria that showed most consistent use were continuity of bony bridging, radiolucency around the cage, and angular motion <5°. However, reliability and accuracy studies were scarce.

CONCLUSION

This review highlights the challenges in reaching consensus on IF assessment. The variability in IF assessment is very high, which limits the translatability of studies. Accuracy studies are needed to guide innovations of assessment. Future IF assessment strategies should focus on the standardization of computed tomography-based continuity of bony bridging. Knowledge from preclinical and imaging studies can add valuable information to this ongoing discussion.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Paracoccygeal Transsacral Approach: A Rare Approach for Axial Lumbosacral Interbody Fusion

Lumbosacral interbody fusion is a mainstay of surgical treatment for degenerative spinal pathologies causing chronic pain and functional impairment. However, the optimal technique for this procedure remains controversial. Well-established open approaches, including anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), and transforaminal lumbar interbody fusion (TLIF), have historically been the standard of practice. A recent paradigm shift in spinal surgery has led to the investigation of minimally invasive approaches to mitigate tissue damage without compromising outcomes. This extensive review aims to examine current clinical and biomechanical evidence on the paracoccygeal transsacral approach to an axial lumbosacral interbody fusion. Since this technique was first described in 2004, accumulating evidence suggests it results in high fusion rates, consistent improvements in pain and function, reduced perioperative morbidity, and low rates of complication. Although early clinical outcomes have been promising, there is a paucity of comparative data investigating outcomes of the paracoccygeal transsacral approach to traditional alternatives and other minimally invasive techniques. Here, we summarize current evidence and discuss pertinent topics for the spinal surgeon considering this novel approach, including indications, advantages, relevant anatomy, contraindications, and technical considerations.

Lateral Approaches for the Surgical Treatment of Lumbar Spondylolisthesis

Spondylolisthesis is a common cause of lower back pain in people of all ages. When nonsurgical management is unsuccessful in treatment for lumbar spondylolisthesis, surgical treatment algorithms can be used. This article focuses on lateral lumbar interbody fusion (LLIF). It represents a minimally invasive approach that affords surgeons an increased ability to restore disc height, indirectly decompress the neural elements, and affect global spinal alignment. As the role for circumferential minimally invasive spine surgery continues to expand, the use of LLIF in the setting of spondylolisthesis-and other pathologies-will continue to represent a robust fusion option.

Optimal axis for lumbosacral interbody fusion: Prospective finite element analysis and retrospective 3D-CT measurement

A feasible and optimal axis of biomechanical and anatomic significance in axial lumbosacral interbody fusion (AxiaLIF) was designed. Using the image dataset of an adult volunteer, two groups of finite element (FE) models of the AxiaLIF, lumbosacral anterior column fixation (ACF) models and middle column fixation (MCF) models with different bone graft fusion degrees, were prospectively established, and their biomechanical differences were comparatively predicted. In addition, 3D reconstruction was performed by retrospectively collecting CT data from pelvises in 60 adult cases. Their anatomic parameters relating to two groups of models were digitally measured and statistically compared. Numerical analysis revealed that the load and the maximum stress on the screw as well as the maximum stress difference between the screw and peripheral tissues in the MCF model were reduced compared with the ACF model. These indices of both models all decreased markedly in response to the increase in the disc fusion degree. Statistical analysis revealed that the effective fixed length of the sacrum in the MCF model was increased compared with the ACF model (P < 0.05). The surgical dissection distance of presacral vessels and nerves from the axis to sacrum of the MCF model was reduced compared with the ACF model (P < 0.05). The feasible and optimal axis of biomechanical and anatomic significance of the AxiaLIF is similar to the axis of the MCF model. Disc bone graft fusions plus axial screw fixations of middle column could strengthen the biomechanical stability of the AxiaLIF model. Clin. Anat. 32:337-347, 2019. © 2018 Wiley Periodicals, Inc.

Bowel injury in lumbar spine surgery: a review of the literature

Although rarely documented in the medical literature, bowel perforation injury can be a severe complication of spine surgery. Our goal was to review current literature regarding this complication and study possible methods of avoidance. We conducted a literature search in the PubMed database between January 1960 and March 2016 using the terms abrasion, bowels, bowel, complication, injury, intestine, intra-abdominal sepsis/shock, perforation, lumbar, spine, surgery, visceral. Diagnostic criteria, outcomes, risk factors, surgical approach, and treatment strategy were the parameters extracted from the search results and used for review. Thirty-one patients with bowel injury were recognized in the literature. Bowel injury was more frequent in patients who underwent lumbar discectomy and microdiscectomy (18 of 31 patients, 58.1%). Minimally invasive surgery and lateral techniques involving fusions accounted for 10 of the reported cases (32.3%). Finally, 2 cases (6.5%) were reported in conjunction with sacrectomies and 1 case (3.2%) with posterior fusion plus anterior longitudinal ligament (ALL) release. Diagnosis was made mostly by clinical signs/symptoms of acute abdominal pain, post-surgical wound infection, and abscess or enterocutaneous fistulas. Significant risk factors for postoperative bowel injury were complex surgical anatomy, medical history of previous abdominal surgeries or infections, irradiation before surgery, errors related to surgical technique, lack of surgical experience, and instrumentation failure. The overall mortality rate from bowel injury was 12.9% (4 of 31 patients). The overall morbidity rate was 87.1% (27 of 31 patients). According to our review of the literature, bowel injury is linked to significant morbidity and mortality. It can be prevented with meticulous pre-surgical planning. When it occurs, timely treatment reduces the risks of morbidity and mortality.

Anterior Lumbar Interbody Fusion With and Without an "Access Surgeon": A Systematic Review and Meta-analysis

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVE

The aim of this study was to investigate the outcomes of anterior lumber interbody fusion (ALIF) with and without an "access surgeon."

SUMMARY OF BACKGROUND DATA

Anterior approaches for spine operations have become increasingly popular but may often involve unfamiliar anatomy and territory for spine surgeons, potentially placing the patient at risk to a greater proportion of approach-related complications. Thus, many spine surgeons require or prefer the assistance of an "access surgeon" to perform the exposure. However, there has been much debate about the necessity of an "access surgeon."

METHODS

A systematic search of six databases from inception to April 2016 was performed by two independent reviewers. Meta-analysis was used to pool overall rates, and compare the outcomes of ALIF with an access surgeon and without.

RESULTS

A total of 58 (8028 patients) studies were included in this meta-analysis. The overall intraoperative complications were similar with and without an "access surgeon." The overall pooled rate of arterial injuries [no access 0.44% vs. access 1.16%, odds ratio (OR) 2.67, P < 0.001], retrograde ejaculation (0.41% vs. 0.96%, OR 2.34, P = 0.005), and ileus (1.93% vs. 2.26%, OR 2.45, P < 0.001) was higher with an "access surgeon." However, the overall pooled rates of peritoneal injury (0.44% vs. 0.16%, OR 0.36, P = 0.034) and neurological injury (0.99% vs. 0.11%, OR 0.11, P < 0.001) were lower with an "access surgeon." Total postoperative complications (5.95% vs. 4.08%, OR 0.67, P < 0.001) were lower with an "access surgeon" along with prosthesis complications (1.59% vs. 0.89%, OR 0.56, P < 0.001) and reoperation rates (2.28% vs. 1.31%, OR 0.57, P < 0.001).

CONCLUSION

Compared with no access surgeon, the use of an access surgeon was associated with similar intraoperative complication rates, higher arterial injuries, retrograde ejaculation, ileus, and lower prosthesis complications, reoperation rates, and postoperative complications. In cases wherein exposure may be difficult, support from an "access surgeon" should be available.

LEVEL OF EVIDENCE

1.

Minimally invasive transaxial lumbosacral interbody fusion: a ten year single-centre experience

PURPOSE

Our aim was to evaluate mid- and long-term results in a cohort of patients who underwent minimally invasive transaxial lumbosacral fixation and to identify clinical and other parameters that can aid in proper patient selection.

METHODS

Over a period of ten years, we assessed 164 patients who had a complete follow-up of a minimum of one year (average 54 months). On follow-up, we recorded clinical status, fusion status, visual analogue scale (VAS), Oswestry Lower Back Pain Disability Index (ODI) scores and patient satisfaction.

RESULTS

There were no intra- or peri-operative complications. Overall clinical success rate was 73.8 %. Only sex (female), working status (still working), body mass index (BMI) (lower) and presence of Modic II changes (absent) were correlated with a good result.

CONCLUSIONS

Transaxial fixation is a safe, minimally invasive technique that can offer good results in patients with single-level degenerative disc disease (DDD) at the lumbosacral level, with minimal operative risk.

Anterior lumbar spine surgery: a systematic review and meta-analysis of associated complications

BACKGROUND CONTEXT

The anterior approach to the lumbar spine is increasingly used to accomplish various surgical procedures. However, the incidence and risk factors for complications associated with anterior lumbar spine surgery (ALS) have not been fully elucidated.

PURPOSE

To identify and document types of complications and complication rates associated with ALS, determine risk factors for these events, and evaluate the effect of measures used to decrease complication rates.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic review of the English-language literature was conducted for articles published between January 1992 and December 2013. A MEDLINE search was conducted to identify articles reporting complications associated with ALS. For each complication, the data were combined using a generalized linear mixed model with a binomial probability distribution and a random effect based on the study. Predictors used were the type of procedure (open, minimally invasive, or laparoscopic), the approach used (transperitoneal vs. retroperitoneal), use of recombinant bone morphogenetic protein-2, use of preoperative computed tomography angiography (CTA), and the utilization of an access surgeon. Open surgery was used as a reference category.

RESULTS

Seventy-six articles met final inclusion criteria and reported complication rates in 11,410 patients who underwent arthrodesis and/or arthroplasty via laparoscopic, mini-open, and open techniques. The overall complication rate was 14.1%, with intraoperative and postoperative complication rates of 9.1% and 5.2%, respectively. Only 3% of patients required reoperation or revision procedures. The most common complications reported were venous injury (3.2%), retrograde ejaculation (2.7%), neurologic injury (2%), prosthesis related (2%), postoperative ileus (1.4%), superficial infection (1%), and others (1.3%). Laparoscopic and transperitoneal procedures were associated with higher complication rates, whereas lower complication rates were observed in patients receiving mini-open techniques. Our analysis indicated that the use of recombinant bone morphogenetic protein-2 was associated with increased rates of retrograde ejaculation; however, there may be limitations in interpreting these data. Data regarding the use of preoperative CTA and an access surgeon were limited and demonstrated mixed benefit.

CONCLUSIONS

Overall complication rates with ALS are relatively low, with the most common complications occurring at a rate of 1% to 3%. Complication rates are related to surgical technique, approach, and implant characteristics. Further randomized controlled trials are needed to validate the use of preventative measures including CTA and the use of an access surgeon.

Axial lumbar interbody fusion: a 6-year single-center experience

Introduction

Methods

Results

Conclusion

Retrospective analysis of L5-S1 axial lumbar interbody fusion (AxiaLIF): a comparison with and without the use of recombinant human bone morphogenetic protein-2

BACKGROUND CONTEXT

Since approval by the Food and Drug Administration in 2002, use of recombinant human bone morphogenetic protein-2 (rhBMP-2) to promote spinal fusion is increasing.

PURPOSE

In this comparative analysis, the authors assess fusion rates and clinical outcomes of patients who underwent a presacral axial lumbar interbody fusion (AxiaLIF) (TranS1 Inc., Wilmington, NC, USA) at L5-S1 with posterior instrumentation, with or without rhBMP-2.

STUDY DESIGN

Retrospective case-matched chart review.

PATIENT SAMPLE

A matched cohort of 99 patients underwent fusion performed by two surgeons at two institutions (2005-2007): Specifically, 45 patients at The Christ Hospital received rhBMP-2 and 54 patients at the University of Pittsburgh had no rhBMP-2.

OUTCOME MEASURES

Pre- and postoperative visual analog scale (VAS) scores were recorded, as was physiologic data on fusion rates, blood loss, and length of stay. Preoperative and postoperative Oswestry Disability Index (ODI) scores were obtained for patients treated with rhBMP-2. Odom's outcome criteria were obtained at 2-year follow-up for patients without rhBMP-2.

METHODS

Data were collected prospectively. Demographic data, including sex and age, were matched.

RESULTS

During the 2-year follow-up period, patients noted reduction in back pain and improved functional outcome measures. The most rapid reduction in VAS pain scores and improvement in ODI occurred within the first 3 months after surgery. Mean pre- and postoperative VAS scores improved 59% from 72.9 to 30.1 with rhBMP-2 and 72% from 81.3 to 22.6 without rhBMP-2. In rhBMP-2-treated patients, mean ODI scores were 54.4% preoperatively and 23.7% postoperatively, a 56.4% improvement at 2 years. In the non-rhBMP-2 patients, 80% reported excellent to good results using Odom criteria. Fusion rates were 96% with rhBMP-2 and 93% without rhBMP-2. Operative blood loss averaged 82 cm(3) with and less than 50 cm(3) without rhBMP-2. No differences in hospital length of stay were noted between the two groups or in the fusion rates with pedicle screws or facet screws. No major complications occurred with or without rhBMP-2.

CONCLUSIONS

In our case-matched series, clinical outcomes were similar for patients who underwent an AxiaLIF L5-S1 interbody fusion with or without rhBMP-2. The data strongly suggest that there is a high confidence for no effect on fusion rate by using rhBMP-2.

AxiaLIF system: minimally invasive device for presacral lumbar interbody spinal fusion

Lumbar fusion is commonly performed to alleviate chronic low back and leg pain secondary to disc degeneration, spondylolisthesis with or without concomitant lumbar spinal stenosis, or chronic lumbar instability. However, the risk of iatrogenic injury during traditional anterior, posterior, and transforaminal open fusion surgery is significant. The axial lumbar interbody fusion (AxiaLIF) system is a minimally invasive fusion device that accesses the lumbar (L4–S1) intervertebral disc spaces via a reproducible presacral approach that avoids critical neurovascular and musculoligamentous structures. Since the AxiaLIF system received marketing clearance from the US Food and Drug Administration in 2004, clinical studies of this device have reported high fusion rates without implant subsidence, significant improvements in pain and function, and low complication rates. This paper describes the design and approach of this lumbar fusion system, details the indications for use, and summarizes the clinical experience with the AxiaLIF system to date.