An analysis of general surgery-related complications in a series of 412 minilaparotomic anterior lumbosacral procedures

Advances in implants and bone graft types for lumbar spinal fusion surgery

The increasing prevalence of spinal disorders worldwide necessitates advanced treatments, particularly interbody fusion for severe cases that are unresponsive to non-surgical interventions. This procedure, especially 360° lumbar interbody fusion, employs an interbody cage, pedicle screw-and-rod instrumentation, and autologous bone graft (ABG) to enhance spinal stability and promote fusion. Despite significant advancements, a persistent 10% incidence of non-union continues to result in compromised patient outcomes and escalated healthcare costs. Innovations in lumbar stabilisation seek to mimic the properties of natural bone, with evolving implant materials like titanium (Ti) and polyetheretherketone (PEEK) and their composites offering new prospects. Additionally, biomimetic cages featuring precisely engineered porosities and interconnectivity have gained traction, as they enhance osteogenic differentiation, support osteogenesis, and alleviate stress-shielding. However, the limitations of ABG, such as harvesting morbidities and limited fusion capacity, have spurred the exploration of sophisticated solutions involving advanced bone graft substitutes. Currently, demineralised bone matrix and ceramics are in clinical use, forming the basis for future investigations into novel bone graft substitutes. Bioglass, a promising newcomer, is under investigation despite its observed rapid absorption and the potential for foreign body reactions in preclinical studies. Its clinical applicability remains under scrutiny, with ongoing research addressing challenges related to burst release and appropriate dosing. Conversely, the well-documented favourable osteogenic potential of growth factors remains encouraging, with current efforts focused on modulating their release dynamics to minimise complications. In this evidence-based narrative review, we provide a comprehensive overview of the evolving landscape of non-degradable spinal implants and bone graft substitutes, emphasising their applications in lumbar spinal fusion surgery. We highlight the necessity for continued research to improve clinical outcomes and enhance patient well-being.

Challenges and Solutions in Postoperative Complications: A Narrative Review in General Surgery

In general surgery, the goal of achieving favorable results following surgical procedures is consistently impeded by the intricate range of postoperative problems. This abstract summarizes a comprehensive narrative study that examines the numerous difficulties associated with postoperative complications and investigates potential remedies. With the progress of surgical practices, the intricacies of complications also increase, requiring a flexible comprehension of the diverse scenarios. This review examines the many factors contributing to postoperative complications, including patient-specific variables and advancing surgical procedures. It also explores the broader consequences of these problems on individual patients and healthcare systems. The economic results, such as extended hospitalizations and increased allocation of resources, highlight the need for specific solutions. This abstract also emphasizes the review's examination of novel methodologies, technology incorporations, and cooperative tactics as potential transformative factors. This abstract provides an overview of the ongoing efforts to change how postoperative complications are understood in general surgery. It highlights the importance of taking preventive measures and adopting a comprehensive approach to patient care.

Contemporary Approaches to Hernia Repair: A Narrative Review in General Surgery

This narrative review offers a thorough and inclusive examination of modern techniques for hernia repair in general surgery. This exploration spans the development of new methods, substances, and technology, providing insight into the significant changes in hernia treatment in recent years. An extensive examination of peer-reviewed literature, encompassing historical advancements, conventional approaches, and the rise of contemporary surgical tactics, was undertaken. Key focus areas include integrating mesh technology, minimally invasive procedures, biological meshes, and 3D printing improvements. The overview explains the historical development from traditional open surgeries to the introduction of laparoscopic procedures, providing detailed information on several modern approaches. The presentation includes information on the utilization of mesh, concerns particular to individual patients, and the increasing importance of robots. An extensive analysis examines complications, obstacles, and current trends, thoroughly assessing safety profiles and patient outcomes. This review aims to consolidate existing information, highlight areas lacking research, and provide future paths to enhance outcomes for patients undergoing general surgery. At the same time, the field of hernia repair experiences significant changes. The integration of classic and contemporary approaches illustrates the changing character of hernia repair, enabling a nuanced understanding among physicians and academics alike.

Risk Factors for Postoperative Ileus in Patients Undergoing Spine Surgery

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

Postoperative ileus (POI) is a common complication following elective spinal surgeries. The aim of this study was to determine the incidence of POI and identify demographic and surgical risk factors for developing POI after elective instrumented fusion of the thoracolumbar spine.

METHODS

The University of Utah Institutional Review Board (IRB) approved this retrospective study. The study does not require informed consent given the data reviewed was deidentified and collected in accordance with the institution's standard of care. A designated IRB committee determined that study is exempt under exemption category 7. IRB approval number 00069703. Patients undergoing instrumented thoracolumbar fusion for one or more levels were retrospectively identified from an internal spine surgery database. Cases performed for trauma, infection, or tumors were excluded. Demographics, medical comorbidities, surgical variables, and opioid medication administration (morphine milligram equivalents, MME) were abstracted from the electronic medical record. Univariate analysis was used to identify variables associated with POI. These variables were then tested for independent association with POI using multivariate logistic regression.

RESULTS

418 patients were included in the current study. The incidence of POI was 9.3% in this cohort. There was no significant relationship between development of POI and patient age, gender, BMI, diabetes mellitus, thyroid dysfunction, lung disease, CKD, GERD, smoking status, alcohol abuse, anemia, or prior abdominal surgery. Univariate analysis demonstrated significant association between POI and fusion ≥7 levels compared to fusions of fewer levels (P = .001), as well as intraoperative sufentanil compared to other opioids (35.9% vs 20.1%, P = .02). POI was not significantly associated with total intraoperative MME, approach, use of interbody cage, or osteotomy. Multivariate logistic regression confirmed total 24-hour postoperative MME as an independent risk factor for POI (OR 1.004, P = .04), however, intraoperative sufentanil administration was not an independent risk factor for POI when controlling for other variables.

CONCLUSIONS

This retrospective cohort study demonstrates that greater postoperative MME is an independent risk factor for POI after thoracolumbar spine fusion when accounting for demographic, medical, and surgical variables with multiple logistic regression. Prospective studies are warranted to evaluate clinical measures to decrease the risk of POI among patients undergoing instrumented thoracolumbar spinal fusions.

Risk factors for postoperative sympathetic chain dysfunction following oblique lateral lumbar interbody fusion: a multivariate analysis

PURPOSE

Postoperative sympathetic chain dysfunction (PSCD) was a relatively common complication after anterior lumbar interbody fusion due to the manipulation adjacent to the lumbar sympathetic chain (LSC). This study aimed to investigate the incidence of PSCD and identify its related independent risk factors after oblique lateral lumbar interbody fusion (OLIF) surgery.

METHODS

PSCD was defined as either of the following in the affected lower limb compared to the contralateral: (1) increase in skin temperature by 1 ºC or more, (2) reduced skin perspiration, (3) limb swelling or skin discoloration. Consecutive patients who underwent OLIF at L4/5 level from February 2018 and May 2022 at a single institution were retrospectively reviewed and divided into two groups: patients with PSCD and patients without PSCD. Binary logistic regression analyses were performed on patients' demographic, comorbidities, radiological datum and perioperative factors to identify independent risk factors for PSCD.

RESULTS

Twelve (5.7%) of 210 patients experienced PSCD following OLIF surgery. Multivariate logistic regression analysis identified the identification of lumbar dextroscoliosis (OR = 7.907, P = 0.012) and the presence of "tear-drop" psoas (OR = 7.216, P = 0.011) as independent risk factors for the PSCD following OLIF.

CONCLUSION

This study identified the lumbar dextroscoliosis and the "tear-drop" psoas as independent risk factors for the development of PSCD after OLIF. Spine alignment examination and the morphological identification of psoas major muscle should be highly noticed for the PSCD prevention following OLIF.

Anterior spine surgery for the treatment of complex spine pathology: a state-of-the-art review

The use of anterior spinal surgery for the treatment of spinal pathology has experienced a dramatic increase over the past decade. Long relegated to treat complicated anterior pathologies it has returned to mainstream spine surgery techniques for all types of conditions, providing a significant boost to the spine surgeons' armamentarium to address a wide variety of types of spinal diseases more effectively. Anterior surgery is useful whenever there is significant spinal pathology that requires direct visualization of the anterior vertebral column to best restore spinal alignment, structural integrity and neurologic function. These pathologies include spinal deformities, tumors, burst fractures, infections, vertebral avascular necrosis, pseudoarthrosis and other miscellaneous indications. Currently available approaches to the spine include transabdominal, paramedian retroperitoneal, lateral oblique retroperitoneal, thoracotomy, and thoracolumbar extensile. Most of the lumbar approaches are now done through a muscle splitting, minimalistic approach that has decreased their morbidity or more recently via tubular approaches, such as lateral lumbar interbody fusions or other ante-psoas approaches. New retractors, instrumentation, hyperlordotic implants, approved biologics and even image guidance for disc preparation and precise implant placement are all recent advances that will hopefully improve surgical outcomes in patients following anterior spinal surgery. Most importantly, these approaches require added expertise and training with a dedicated team consisting of an anteriorly trained spine surgeon working simultaneously with a dedicated vascular surgeon to ensure maximum safety and superior patient outcomes. This state of the review is dedicated to familiarizing practicing spine surgeons with the most commonly used anterior spinal approaches along with cutting-edge instrumentation and fusion techniques to improve their options for the treatment of difficult spinal pathologies.

Clinical presentation and surgical anatomy of sympathetic nerve injury during lumbar spine surgery: a narrative review

BACKGROUND AND OBJECTIVE

To highlight the surgical anatomy, procedural variations, presentation, and management of sympathetic nerve injury after surgery of the lumbar spine.

METHODS

PubMed and Google Scholar were searched for publications that were completed between 1951 and 2021. Relevant full-text articles published in the English language were selected and critically reviewed.

KEY CONTENT AND FINDINGS

Sympathetic injury is a highly variable postsurgical complication with a greater incidence after an anterior or oblique approach to the lumbar spine compared to posterior and lateral approaches. The direct and extreme lateral approaches reduce the need to disturb sympathetic nerves thus reducing the risk of complications. It can present in multiple manners, including complex regional pain syndrome (CRPS) and retrograde ejaculation. These complications can be transient and resolve spontaneously or be treated with medications, physical therapy, and spinal blocks. The severity of the conditions and extent of recovery can vary drastically, with some patients never fully recovering.

CONCLUSIONS

To access the lumbar spine, there are operational approaches and techniques that should be used to decrease the risk of intraoperative injury. It is crucial to understand the advantages and risks to different approaches and take the necessary steps to minimize complications. Early identification of dysfunction and adequate management of symptoms are imperative to effectively manage patients with lumbar sympathetic trunk and sympathetic nerve fiber injuries.

Retrograde ejaculation following anterior lumbar surgery: a systematic review and pooled analysis

OBJECTIVE

The present systematic review and pooled analysis aims to assess the incidence and risk factors for the development of retrograde ejaculation (RE) following first-time open anterior lumbar surgery.

METHODS

A systematic MEDLINE review via PubMed was performed, identifying 130 clinical papers relating to the topic. Eighteen publications were selected according to predetermined inclusion and exclusion criteria and were used to determine the incidence of RE. Only the publications that provided data on surgical risk factors present specifically in the men in the study were included in the analysis of risk factors.

RESULTS

Of the 2503 men included, there were 57 reported events of RE (2.3%). Of the cases for which long-term data were provided, 45.8% had resolved by final follow-up. There was a statistically significant increased risk associated with a transperitoneal as opposed to a retroperitoneal approach (8.6% vs 3.2%), as well as with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior lumbar interbody fusion (ALIF) as opposed to ALIF with bone graft or arthroplasty in controls (5.0% vs 1.8%). However, when excluding from analysis the patients operated on prior to the FDA's 2008 warning that commented on the drug's neuroinflammatory properties, there was no significant difference in rates of RE in patients receiving rhBMP-2 versus the control group (2.4% vs 2.5%). There was no significant difference in risk based on single- versus multilevel procedure or on ALIF versus arthroplasty.

CONCLUSIONS

In a pooled analysis of currently published data on men undergoing first-time open anterior lumbar surgery, this study found an overall incidence of RE of 2.3%. Nearly half of these patients recovered, reporting resolution of symptoms anywhere between 3 months and 48 months. Analysis of risk factors was limited by a paucity of published literature segregating data by sex. However, there was an increased risk associated with rhBMP-2 only when including data collected prior to the FDA warning on its detrimental properties. The authors therefore posit that the risk of RE is probably overestimated in the literature, given that the vast majority of the data available were collected prior to this warning and given the subsequent implementation of precautions when handling rhBMP-2.

Postoperative adverse events secondary to iatrogenic vascular injury during anterior lumbar spinal surgery

BACKGROUND

Anterior lumbar spine surgery (ALSS) requires mobilization of the great vessels, resulting in a high risk of iatrogenic vascular injury (VI). It remains unclear whether VI is associated with increased risk of postoperative complications and other related adverse outcomes.

PURPOSE

The purpose of this study was to (1) assess the incidence of postoperative complications attributable to VI during ALSS, and (2) outcomes secondary to VI such as procedural blood loss, transfusion of blood products, length of stay (LOS), and in hospital mortality.

STUDY DESIGN

Retrospective propensity-score matched, case-control study at 2 academic and 3 community medical centers, PATIENT SAMPLE: Patients 18 years of age or older, undergoing ALSS between January 1st, 2000 and July 31st, 2019 were included in this analysis.

OUTCOME MEASURES

The primary outcome was the incidence of postoperative complications attributable to VI, such as venous thromboembolism, compartment syndrome, transfusion reaction, limb ischemia, and reoperations. The secondary outcomes included estimated operative blood loss (milliliter), transfused blood products, LOS (days), and in-hospital mortality.

METHODS

In total, 1,035 patients were identified, of which 75 (7.2%) had a VI. For comparative analyses, the 75 VI patients were paired with 75 comparable non-VI patients by propensity-score matching. The adequacy of the matching was assessed by testing the standardized mean differences (SMD) between VI and non-VI group (>0.25 SMD).

RESULTS

Two patients (2.7%) had VI-related postoperative complications in the studied period, which consisted of two deep venous thromboembolisms (DVTs) occurring on day 3 and 7 postoperatively. Both DVTs were located in the distal left common iliac vein (CIV). The VI these patients suffered were to the distal inferior vena cava and the left CIV, respectively. Both patients did not develop additional complications in consequence of their DVTs, however, did require systemic anticoagulation and placement of an inferior vena cava filter. There was no statistical difference with the non-VI group where no instances (0%) of postoperative complications were reported (p=.157). No differences were found in LOS or in hospital mortality between the two groups (p=.157 and p=.999, respectively). Intraoperative blood loss and blood transfusion were both found to be higher in the VI group in comparison to the non-VI group (650 mL, interquartile range [IQR] 300-1400 vs. 150 mL, IQR 50-425, p≤.001; 0 units, IQR 0-3 vs. 0 units, IQR 0-1, p=.012, respectively).

CONCLUSION

This study found a low number of serious postoperative complications related to VI in ALSS. In addition, these complications were not significantly different between the VI and matched non-VI ALSS cohort. Although not significant, the found DVT incidence of 2.7% after VI in ALSS warrants vigilance and preventive measures during the postoperative course of these patients.

Management of Vascular Complications during Anterior Lumbar Spinal Surgery Using Mini-Open Retroperitoneal Approach

BACKGROUND

Anterior retroperitoneal spine exposure has become increasingly performed for the surgical treatment of various spinal disorders. Despite its advantages, the procedure is not riskless and can expose to potentially life-threatening vascular lesions. The aim of this review is to report the vascular lesions that can happen during anterior lumbar spinal surgery using mini-open retroperitoneal approach and to describe their management.

METHODS

A systematic literature search was performed according to PRISMA to identify studies published in English between January 1980 and December 2019 reporting vascular complications during anterior lumbar spinal surgery with mini-open retroperitoneal approach. Three authors independently conducted the literature search on PubMed/Medline database using a combination of the following terms: "spinal surgery", "anterior lumbar surgery (ALS)", "anterior lumbar interbody fusion (ALIF)", "lumbar total disc replacement", "artificial disc replacement", "vascular complications", "vascular injuries". Vascular complications were defined as any peri-operative or post-operative lesions related to an arterial or venous vessel. The management of the vascular injury was extracted.

RESULTS

Fifteen studies fulfilled the inclusion criteria. Venous injuries were observed in 13 studies. Lacerations and deep venous thrombosis ranged from 0.8% to 4.3% of cases. Arterial lesions were observed in 4 studies and ranged from 0.4% to 4.3% of cases. It included arterial thrombosis, lacerations or vasospasms. The estimated blood loss was reported in 10 studies and ranged from 50 mL up to 3000 mL. Vascular complications were identified as a cause of abortion of the procedure in 2 studies, representing respectively 0.3% of patients who underwent ALS and 0.5% of patients who underwent ALIF.

CONCLUSION

Imaging pre-operative planning is of utmost importance to evaluate risk factors and the presence of anatomic variations in order to prevent and limit vascular complications. Cautions should be taken during the intervention when manipulating major vessels and routine monitoring of the limb oxygen saturation should be systematically performed for an early detection of arterial thrombosis. The training of the surgeon access remains a key-point to prevent and manage vascular complications during anterior lumbar spinal surgery with mini-open retroperitoneal.

Clinical Evaluation of Microendoscopy-Assisted Oblique Lateral Interbody Fusion

Background and objectives: Oblique Lateral Interbody Fusion (OLIF) is a widely performed, minimally invasive technique to achieve lumbar lateral interbody fusion. However, some complications can arise due to constraints posed by the limited surgical space and visual field. The purpose of this study was to assess the short-term postoperative clinical outcomes of microendoscopy-assisted OLIF (ME-OLIF) compared to conventional OLIF. Materials and Methods: We retrospectively investigated 75 consecutive patients who underwent OLIF or ME-OLIF. The age, sex, diagnosis, and number of fused levels were obtained from medical records. Operation time, estimated blood loss (EBL), and intraoperative complications were also collected. Operation time and EBL were only measured per level required for the lateral procedure, excluding the posterior fixation surgery. The primary outcome measure was assessed using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ). The secondary outcome measure was assessed using the Oswestry Disability Index (ODI) and the European Quality of Life–5 Dimensions (EQ-5D), measured preoperatively and 1-year postoperatively. Results: This case series consisted of 14 patients in the OLIF group and 61 patients in the ME-OLIF group. There was no significant difference between the two groups in terms of the mean operative time and EBL (p = 0.90 and p = 0.50, respectively). The perioperative complication rate was 21.4% in the OLIF group and 21.3% in the ME-OLIF group (p = 0.99). In both groups, the postoperative JOABPEQ, EQ-5D, and ODI scores improved significantly (p < 0.001). Conclusions: Although there was no significant difference in clinical results between the two surgical methods, the results suggest that both are safe surgical methods and that microendoscopy-assisted OLIF could serve as a potential alternative to the conventional OLIF procedure.

Increased vertebral exposure in anterior lumbar interbody fusion associated with venous injury and deep venous thrombosis

BACKGROUND

Published outcomes on anterior lumbar interbody fusion (ALIF) have focused on 1-2 level fusion with and without vascular surgery assistance. We examined the influence of multilevel fusion on exposure-related outcomes when performed by vascular surgeons.

METHODS

We retrospectively reviewed clinical and radiographic data for patients undergoing anterior lumbar interbody fusion (ALIF) with exposure performed by vascular surgeons at a single practice.

RESULTS

From 2017-2018, 201 consecutive patients underwent vascular-assisted ALIF. Patients were divided by number of vertebral levels exposed (90 patients with 1 level exposed, 71 with 2, 40 with 3+). Demographically, 3+ level fusion patients were older (P=.0045) and more likely to have had prior ALIF (P=.0383). Increased vertebral exposure was associated with higher rates of venous injury (P=.0251), increased procedural time (P= .0116), length of stay (P=.0001), and incidence of postoperative DVT (P=.0032). There was a 6.5% rate of intraoperative vascular injury, comprised of 3 major and 10 minor venous injuries. In patients who experienced complications, 92.3% of injuries were repaired primarily. 23% of patients with venous injuries developed postoperative deep venous thrombosis. In a multivariate logistic regression model, increased levels of exposure (RR = 6.23, P = .026) and a history of degenerative spinal disease (RR = .033, P = .033) were predictive of intraoperative venous injury.

CONCLUSIONS

Increased vertebral exposure in anterior lumbar interbody fusion is associated with increased risk of intraoperative venous injury and postoperative deep venous thrombosis, with subsequently greater lengths of procedure time and length of stay. Rates of arterial and sympathetic injury were not affected by exposure extent.

Treatment of lumbosacral tuberculosis by anterior internal fixation combined with computed tomography angiography

OBJECTIVE

This study aims to examine the iliac vascular space in patients with lumbosacral tuberculosis and to evaluate the feasibility of anterior internal fixation for lumbosacral tuberculosis.

METHODS

A retrospective analysis was performed in 36 patients with lumbosacral tuberculosis. The preoperative three-dimensional computed tomography angiography images were analyzed for anatomical parameters.

RESULTS

There were large variations among the anterior lumbosacral iliac vessels. Predominantly, the left iliac vein and the right iliac artery formed the two borders of the triangular iliac vascular space in the coronal plane. The mean distance between the iliac vessels straddle point and the inferior endplate of L5 was 15.01 ± 15.08 mm. In the sagittal plane, presacral abscess increased the distance between the posterior iliac vessel and the anterior vertebra. The distances on the left and right sides were 9.94 ± 6.03 and 10.15 ± 5.46 mm, respectively, at the inferior endplate of L5 and were 11.90 ± 6.97 and 11.68 ± 5.52 mm, respectively, at the superior endplate of S1.

CONCLUSIONS

The space on sagittal plane occupied by presacral abscess may push forward the vessels and therefore provide opportunities for anterior internal fixation.

Extraforaminal L5 Nerve Root Compression Caused by Intervertebral Osteophyte Accompanied by Lumbosacral Transitional Vertebra: A Case Treated by Anterior Approach

BACKGROUND

Several authors have reported the occurrence of extraforaminal L5 nerve root compression between lumbosacral transitional vertebrae (LSTV) and sacral ala, but reports on a lesion caused by an intervertebral osteophyte on the ventral and contralateral side of a unilateral abnormality by LSTV are hardly available.

CASE DESCRIPTION

A 67-year-old woman presented with pain along the distribution of the L5 nerve root; straight leg raise test, femoral nerve stretch test, and Kemp test were positive on the left. Following plain radiographs, computerized tomography, magnetic resonance imaging, and selective nerve root block, an osteophyte bridging the L5 and S1 vertebral bodies in the ventral side was identified compressing the L5 nerve root. On account of resistance to conservative therapy and the delicate position of the lesion, surgical treatment was performed by an anterior decompression. Subsequently, the patient attained adequate relief from pain and could walk normally.

CONCLUSION

We herein present a very rare case of extraforaminal L5 nerve root compression caused by an intervertebral osteophyte on the ventral and contralateral side of a unilateral abnormality by LSTV, which was managed by anterior decompression.

Sexual activity after spine surgery: a systematic review

INTRODUCTION

Sexual function is an important determinant of quality of life, and factors such as surgical approach, performance of fusion, neurological function and residual pain can affect it after spine surgery. Our aim was to perform a systematic review to collate evidence regarding the impact of spine surgery on sexual function.

METHODS

A systematic review of studies reporting measures of sexual function, and incidence of adverse sexual outcomes (retrograde ejaculation) after major spine surgery was done, regardless of spinal location. Pubmed (MEDLINE) and Google Scholar databases were queried using the following search words "Sex", "Sex life", "Sexual function", "Sexual activity", "retrograde ejaculation", "Spine", "Spine surgery", "Lumbar surgery", "Lumbar fusion", "cervical spine", "cervical fusion", "Spinal deformity", "scoliosis" and "Decompression". All articles published between 1997 and 2017 were retrieved from the database. A total of 81 studies were included in the final review.

RESULTS

Majority of the studies were retrospective case series and were low quality (Level IV) in evidence. Anterior lumbar approaches were associated with a higher incidence of retrograde ejaculation, especially with the utilization of transperitoneal laparoscopic approach. There is inconclusive evidence on the preferred sexual position following fusion, and also on the impact of BMP-2 usage on retrograde ejaculation/sexual dysfunction.

CONCLUSION

Despite limited evidence from high-quality articles, there is a general trend towards improvement of sexual activity and function after spine surgery. Future studies incorporating specific assessments of sexual activity will be required to address this important determinant of quality of life so that appropriate pre-operative counselling can be done by providers. These slides can be retrieved under Electronic Supplementary Material.

Understanding Retroperitoneal Anatomy for Lateral Approach Spine Surgery

Lateral approach spine surgery provides effective interbody stabilization, and correction and indirect neural decompression with minimal-incision and less invasive surgery compared with conventional open anterior lumbar fusion. It may also avoid the trauma to paraspinal muscles or facet joints found with transforaminal lumbar interbody fusion and posterior lumbar interbody fusion. However, because lateral approach surgery is fundamentally retroperitoneal approach surgery, it carries potential risk to intra- and retroperitoneal structures, as seen in a conventional open anterior approach. There is an innovative lateral approach technique that reveals different anatomical views; however, it requires reconsideration of the traditional surgical anatomy in more detail than a traditional open anterior approach. The retroperitoneum is the compartmentalized space bounded anteriorly by the posterior parietal peritoneum and posteriorly by the transversalis fascia. The retroperitoneum is divided into three compartments by fascial planes: anterior and posterior pararenal spaces and the perirenal space. Lateral approach surgery requires mobilization of the peritoneum and its content and accurate exposure to the posterior pararenal space. The posterior pararenal space is confined anteriorly by the posterior renal fascia, anteromedially by the lateroconal fascia, and posteriorly by the transversalis fascia. The posterior renal fascia, the lateroconal fascia or the peritoneum should be detached from the transversalis fascia and the psoas fascia to allow exposure to the posterior pararenal space. The posterior pararenal space, however, does not allow a clear view and identification of these fasciae as this relationship is variable and the medial extent of the posterior pararenal space varies among patients. Correct anatomical recognition of the retroperitoneum is essential to success in lateral approach surgery. Spine surgeons must be aware that the retroperitoneal membrane and fascia is multilayered and more complex than is commonly understood. Preoperative abdominal images would facilitate more efficient surgical considerations of retroperitoneal membrane and fascia in lateral approach surgery.

Complications Associated With Bone Morphogenetic Protein in the Lumbar Spine

Complications associated with the use of recombinant human bone morphogenetic protein in the lumbar spine include retrograde ejaculation, ectopic bone formation, vertebral osteolysis and subsidence, postoperative radiculitis, and hematoma and seroma. These complications are controversial and remain widely debated. This article discusses the reported complications and possible implications for the practicing spine surgeon. Understanding the complications associated with the use of recombinant human bone morphogenetic protein and the associated controversies allows for informed decision making by both the patient and the surgeon. [Orthopedics. 2017; 40(2):e229-e237.].

The Influence of Common Medical Conditions on the Outcome of Anterior Lumbar Interbody Fusion

STUDY DESIGN

The authors retrospectively reviewed a consecutive series of 231 patients with anterior lumbar interbody fusion (ALIF).

OBJECTIVE

To determine the correlations among common medical conditions, demographics, and the natural history of lumbar surgery with outcomes of ALIF.

SUMMARY OF BACKGROUND DATA

Multiple spinal disorders are treated with ALIF with excellent success rates. Nonetheless, adverse outcomes and complications related to patients' overall demographics, comorbidities, or cigarette smoking have been reported.

METHODS

The age, sex, body mass index (BMI), comorbidities, history of smoking or previous lumbar surgery, operative parameters, and complications of 231 patients who underwent ALIF were analyzed. Regression analyses of all variables with complications and surgical outcomes based on total Prolo scores were performed. Two models predicting Prolo outcome score were generated. The first model used BMI and sex interaction, whereas the second model used sex, level of surgery, presence of diabetes mellitus, and BMI as variables.

RESULTS

At follow-up, the rate of successful fusion was 99%. The overall complication rate was 13.8%, 1.8% of which occurred intraoperatively and 12% during follow-up. The incidence of complications failed to correlate with demographics, comorbidities, smoking, or previous lumbar surgery (P>0.5). ALIF at T12-L4 was the only factor significantly associated with poor patient outcomes (P=0.024). Both models successfully predicted outcome (P=0.05), although the second model did so only for males.

CONCLUSIONS

Surgical level of ALIF correlated with poor patient outcomes as measured by Prolo functional scale. BMI emerged as a significant predictor of Prolo total score. Both multivariate models also successfully predicted outcomes. Surgical or follow-up complications were not associated with patients' preoperative status.

A Review of the Clinical Side Effects of Bone Morphogenetic Protein-2

Bone morphogenetic protein-2 (BMP-2) is currently the only Food and Drug Administration (FDA)-approved osteoinductive growth factor used as a bone graft substitute. However, with increasing clinical use of BMP-2, a growing and well-documented side effect profile has emerged. This includes postoperative inflammation and associated adverse effects, ectopic bone formation, osteoclast-mediated bone resorption, and inappropriate adipogenesis. Several large-scale studies have confirmed the relative frequency of adverse events associated with the clinical use of BMP-2, including life-threatening cervical spine swelling. In fact, the FDA has issued a warning of the potential life-threatening complications of BMP-2. This review summarizes the known adverse effects of BMP-2, including controversial areas such as tumorigenesis. Next, select animal models that replicate BMP-2's adverse clinical effects are discussed. Finally, potential molecules to mitigate the adverse effects of BMP-2 are reviewed. In summary, BMP-2 is a potent osteoinductive cytokine that has indeed revolutionized the bone graft substitute market; however, it simultaneously has accrued a worrisome side effect profile. Better understanding of these adverse effects among both translational scientists and clinicians will help determine the most appropriate and safe use of BMP-2 in the clinical setting.

Paralytic Ileus and Prophylactic Gastrointestinal Motility Medication after Spinal Operation

PURPOSE

To investigate the prevalence of paralytic ileus after spinal operation in the supine or prone operative position and to determine the efficacy of prophylactic gastrointestinal motility medications in preventing symptomatic paralytic ileus after a spinal operation.

MATERIALS AND METHODS

All patients received spinal surgery in the supine or prone operative position. The study period was divided into two phases: first, to analyze the prevalence of radiographic and symptomatic paralytic ileus after a spinal operation, and second, to determine the therapeutic effects of prophylactic gastrointestinal motility medications (postoperative intravenous injection of scopolamine butylbromide and metoclopramide hydrochloride) on symptomatic paralytic ileus after a spinal operation.

RESULTS

Basic demographic data were not different. In the first phase of this study, 27 patients (32.9%) with radiographic paralytic ileus and 11 patients (13.4%) with symptomatic paralytic ileus were observed. Radiographic paralytic ileus was more often noted in patients who underwent an operation in the prone position (p=0.044); whereas the occurrence of symptomatic paralytic ileus was not different between the supine and prone positioned patients (p=0.385). In the second phase, prophylactic medications were shown to be ineffective in preventing symptomatic paralytic ileus after spinal surgery [symptomatic paralytic ileus was observed in 11.1% (4/36) with prophylactic medication and 16.7% (5/30) with a placebo, p=0.513].

CONCLUSION

Spinal surgery in the prone position was shown to increase the likelihood of radiographic paralytic ileus occurrence, but not symptomatic paralytic ileus. Unfortunately, the prophylactic medications to prevent symptomatic paralytic ileus after spine surgery were shown to be ineffective.

Impact of inhalation vs. intravenous anaesthesia on autonomic nerves and internal anal sphincter tone

BACKGROUND

Pelvic intraoperative neuromonitoring (pIONM) aims to identify and spare the autonomic nerves and maintain patients' quality of life. The effect of anaesthetic agents on the pIONM signal is unknown; therefore, the aim of the present study was to compare the influences of inhalation anaesthesia (IA) and total intravenous anaesthesia (TIVA).

METHODS

Twenty rectal cancer patients undergoing open nerve-sparing total mesorectal excision (TME) were assigned to pIONM under either IA or TIVA (n = 10 per group). IA was maintained with sevoflurane and TIVA with propofol. During surgery, pelvic autonomic nerves were electrically stimulated under electromyography (EMG) of the internal anal sphincter (IAS). These triggered EMG signals were analysed.

RESULTS

The absolute EMG amplitude during pIONM increased to 1.20 μV (interquartile range (IQR): 0.94-1.6) for IA and 1.49 μV (IQR: 0.84-2.75) for TIVA (P = 0.002). The relative EMG amplitude increase also was significantly lower for IA (0.59; IQR: 0.30-0.81; TIVA: 0.99; IQR: 0.62-2.5), (P = 0.001).

CONCLUSIONS

This is the first study to compare the influences of IA and TIVA on the autonomic nervous system. While both anaesthetic regimens proved useful for pIONM, TIVA with propofol may provide better signal quality than IA with sevoflurane.

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.

Anterior lumbar interbody fusion using recombinant human bone morphogenetic protein-2: a prospective study of complications

OBJECT

The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior lumbar interbody fusion (ALIF) is controversial regarding the reported complication rates and cost. The authors aimed to assess the complication rates of performing ALIF using rhBMP-2.

METHODS

This is a prospective study of consecutive patients who underwent ALIF performed by a single spine surgeon and a single vascular surgeon between 2009 and 2012. All patients underwent placement of a polyetheretherketone (PEEK) cage filled with rhBMP-2 and a separate anterior titanium plate. Preoperative clinical data, operative details, postoperative complications, and clinical and radiographic outcomes were recorded for all patients. Clinical outcome measures included back and leg pain visual analog scale scores, Oswestry Disability Index (ODI), and SF-36 Physical and Mental Component Summary (PCS and MCS) scores. Radiographic assessment of fusion was performed using high-definition CT scanning. Male patients were screened pre- and postoperatively regarding sexual dysfunction, specifically retrograde ejaculation (RE).

RESULTS

The study comprised 131 patients with a mean age of 45.3 years. There were 67 men (51.1%) and 64 women (48.9%). Of the 131 patients, 117 (89.3%) underwent ALIF at L5-S1, 9 (6.9%) at L4-5, and 5 (3.8%) at both L4-5 and L5-S1. The overall complication rate was 19.1% (25 of 131), with 17 patients (13.0%) experiencing minor complications and 8 (6.1%) experiencing major complications. The mean estimated blood loss per ALIF level was 115 ml. There was 1 incidence (1.5%) of RE. No significant vascular injuries occurred. No prosthesis failure occurred with the PEEK cage and separate anterior screw-plate. Back and leg pain improved 57.2% and 61.8%, respectively. The ODI improved 54.3%, with PCS and MCS scores improving 41.7% and 21.3%, respectively. Solid interbody fusion was observed in 96.9% of patients at 12 months.

CONCLUSIONS

Anterior lumbar interbody fusion with a vascular access surgeon and spine surgeon, using a separate cage and anterior screw-plate, provides a very robust and reliable construct with low complication rates, high fusion rates, and positive clinical outcomes, and it is cost-effective. The authors did not experience the high rates of RE reported by other authors using rhBMP-2.

Incidence and risk factors for postoperative ileus following anterior, posterior, and circumferential lumbar fusion

BACKGROUND CONTEXT

Postoperative ileus is a known complication of surgery. The incidence and risk factors for ileus after lumbar fusion surgery is not well characterized.

PURPOSE

To determine rates of postoperative ileus, a population-based database was analyzed to identify incidence, mortality, and risk factors associated with anterior (ALF), posterior (PLF), and combined anterior/posterior (APLF) lumbar fusions.

STUDY DESIGN

This was a retrospective database analysis.

PATIENT SAMPLE

The sample consisted of 220,522 patients from the Nationwide Inpatient Sample (NIS) database.

OUTCOME MEASURES

Outcome measures were incidence of postoperative ileus, length of stay (LOS), in-hospital costs, and mortality.

METHODS

Data from the NIS were obtained from 2002 to 2009. Patients undergoing ALF, PLF, and APLF for degenerative pathologies were identified and the incidence of postoperative ileus was assessed. Patient demographics, Charlson comorbidity index (CCI), LOS, costs, and mortality were assessed. SPSS v.20 was used to detect statistical differences between groups and perform logistic regression analyses to identify independent predictors of postoperative ileus. A p value less than .001 denoted significance.

RESULTS

A total of 220,522 lumbar fusions were identified in the United States from 2002 to 2009. There were 19,762 ALFs, 182,801 PLFs, and 17,959 APLFs. The incidence of postoperative ileus was increased in ALFs over PLFs (74.9 vs. 26.0 per 1,000; p<.001). Within PLF and APLF groups, CCI scores were increased in the presence of postoperative ileus (p<.001). Across cohorts, patients with postoperative ileus demonstrated greater LOS and costs (p<.001). PLF-treated patients with postoperative ileus demonstrated increased mortality (p<.001). Independent predictors of postoperative ileus included male gender, 3+ fusion levels, alcohol abuse, anemia, fluid/electrolyte disorders, and weight loss (p<.001).

CONCLUSIONS

The results of our study demonstrate increased incidence of postoperative ileus associated with anterior approaches for lumbar fusion. Across cohorts, postoperative ileus was associated with increased LOS and costs. To determine the mortality and resource use associated with postoperative ileus, we recommend preoperatively identifying and treating modifiable risk factors, especially when an anterior approach is used.

Complications of spinal fusion with utilization of bone morphogenetic protein: a systematic review of the literature

STUDY DESIGN

Systematic review.

OBJECTIVE

A systematic review was performed to identify the types of complications and complication rates associated with the use of bone morphogenetic protein (BMP) in both anterior and posterior cervical and lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

There has been an increase in BMP use in various clinical situations typically in an "off-label" fashion. Associated with its use, however, have been reports of various complications.

METHODS

A MEDLINE search was conducted. All articles involving complications after spine surgery in patients receiving BMP were included. Articles were excluded on the basis of the following criteria: Non-English manuscripts and nonhuman subjects. A total of 29 articles met the inclusion and exclusion criteria and were used in the analysis. For each complication identified, the incidence was calculated by pooling the subjects from the studies that reported the complication. χ tests were used to compare the incidence rates between those that had received BMP and the control groups.

RESULTS

Of the 29 articles included, 7 reported complication rates in anterior cervical fusions, 3 in posterior cervical fusions, 4 in anterior lumbar interbody fusions (ALIF), 9 in posterior/transforaminal lumbar interbody fusions (PLIF/TLIF), and 6 in posterolateral lumbar fusions. Individual complication rates when BMP was used was in the range from 0.66% to 20.1% in anterior cervical fusions, 3.5% to 14.6% in posterior cervical fusions, 2.0% to 7.3% in ALIFs, 1.5% to 21.8% in PLIF/TLIFs, and 1.4% to 8.2% in posterolateral lumbar fusions. Pseudarthrosis rates were statistically significantly lower with the utilization of BMP in all procedures except for PLIF/TLIFs, which only approached significance (P = 0.07). The only individual complication that was statistically significantly greater with BMP utilization was retrograde ejaculation in ALIFs (7.3 vs. 2.3%; P = 0.03). The rate of dysphagia/swelling in anterior cervical fusions was greater with BMP (20.1 vs. 15.6%), however this only approached statistical significance (P = 0.07).

CONCLUSION

The body of literature reports complication rates with BMP ranging from 0.66% to 21.8%. However, the only statistically significant adverse complication rate was retrograde ejaculation in the ALIF population (7.3%). Despite the increased awareness of complications associated with BMP, complication rates remain spine site specific and low. Thorough patient education should be done with the physician to make an informative use regarding BMP utilization in spinal surgery.

LEVEL OF EVIDENCE

3.

Rectal perforation after AxiaLIF instrumentation: case report and review of the literature

BACKGROUND CONTEXT

Bowel perforation is an uncommon complication of posterior spinal surgery. The AxiaLIF transsacral instrumentation system has been used for the treatment of L5-S1 spondylolisthesis and degenerative disc disease since its introduction in 2005 as a potentially less invasive alternative to traditional anterior or posterior interbody fusion.

PURPOSE

In this article, we report a case of a rectal perforation as a complication of placement of the AxiaLIF instrumentation system that was successfully treated without the removal of the device.

STUDY DESIGN

Case report.

METHODS

The patient presented with progressive back pain and sepsis 3 weeks after an L5-S1 fusion done with the AxiaLIF technique at an outside facility. The patient was managed with antibiotic therapy and a diverting ileostomy, without the removal of the AxiaLIF device.

RESULTS

Over the next year, she had symptoms indicative of nonunion of the operated level and breakdown at the adjacent level, which were confirmed with imaging. She underwent revision posterior spinal fusion without the removal of the AxiaLIF device. Eighteen months after the AxiaLIF device was placed, the patient continued to demonstrate no signs of infection recurrence.

CONCLUSIONS

Delayed presentation of rectal perforation with a subsequent anaerobic sepsis is a potential complication of the presacral approach to the L5-S1 disc space. Recognition and treatment with fecal diversion and long-term intravenous antibiotics is an alternative to device removal and sacral reconstruction.

A systematic review of the correlates and management of nonpremature ejaculatory dysfunction in heterosexual men

INTRODUCTION

A better understanding of ejaculatory disorders has led to an increasing interest in nonpremature ejaculatory dysfunction (non-PE EjD). Current reviews on the subject use a symptom-based classification to describe ejaculatory dysfunction even when it is a single case report. While these reviews provide important information on the disorder, a clearer picture of the prevalence of non-PE EjD in relation to the community and various pathophysiologic states is needed.

OBJECTIVES

The objective of this study was to provide a systematic review of studies of non-PE EjD excluding single case reports.

METHODS

A systematic review of Medline for terms including ejaculation, orgasm or hematospermia. Association with terms delay, pain or headache was made. The search was restricted to male gender and articles written in English. Abstracts were reviewed and those mainly concerned with premature ejaculation were excluded.

RESULTS

A total of 333 articles on non-PE EjD were identified. The condition was reported in community-based studies. In certain patient populations, non-PE EjD was commonly reported in association with antidepressant and antipsychotic treatments, in patients with chronic prostatitis/chronic pelvic pain syndrome, patients with lower urinary tract symptoms particularly in association with medical or surgical treatment, patients with retroperitoneal surgery and in patients with neurological diseases. Few articles were concerned with treatment options.

CONCLUSION

There is a significant prevalence of non-PE EjD in the community and in association with particular disease states or as a side effect of medical or surgical interventions. There is a need to direct efforts to prevent and treat these conditions.

The da Vinci robotic surgical assisted anterior lumbar interbody fusion: technical development and case report

STUDY DESIGN

Technique development to use the da Vince Robotic Surgical System for anterior lumbar interbody fusion at L5-S1 is detailed. A case report is also presented.

OBJECTIVE

To evaluate and develop the da Vinci robotic assisted laparoscopic anterior lumbar stand-alone interbody fusion procedure.

SUMMARY OF BACKGROUND DATA

Anterior lumbar interbody fusion is a common procedure associated with potential morbidity related to the surgical approach. The da Vinci robot provides intra-abdominal dissection and visualization advantages compared with the traditional open and laparoscopic approach.

METHODS

The surgical techniques for approach to the anterior lumbar spine using the da Vinci robot were developed and modified progressively beginning with operative models followed by placement of an interbody fusion cage in the living porcine model. Development continued to progress with placement of fusion cage in a human cadaver, completed first in the laboratory setting and then in the operating room. Finally, the first patient with fusion completed using the da Vinci robot-assisted approach is presented.

RESULTS

The anterior transperitoneal approach to the lumbar spine is accomplished with enhanced visualization and dissection capability, with maintenance of pneumoperitoneum using the da Vinci robot. Blood loss is minimal. The visualization inside the disc space and surrounding structures was considered better than current open and laparoscopic techniques.

CONCLUSION

The da Vinci robot Surgical System technique continues to develop and is now described for the transperitoneal approach to the anterior lumbar spine.

LEVEL OF EVIDENCE

4.

Urological complications following use of recombinant human bone morphogenetic protein-2 in anterior lumbar interbody fusion: presented at the 2012 Joint Spine Section Meeting: clinical article

OBJECT

The goal of this study was to compare the urological complications in patients after anterior lumbar interbody fusion (ALIF) with and without the use of recombinant human bone morphogenetic protein-2 (rhBMP-2).

METHODS

The authors retrospectively reviewed the medical records of all patients who underwent ALIF with and without rhBMP-2 between January 2002 and August 2010. Patient demographic, operative, and complication information was analyzed. Male patients who underwent ALIF between L-4 and S-1 were contacted to assess postoperative urological complications.

RESULTS

Of the 110 male patients who underwent ALIF and were included in this study, 59 were treated with rhBMP-2 and 51 did not receive rhBMP-2. The mean follow-up duration was 17.5 months for the rhBMP-2 group and 30.8 months for the control group. No difference was found regarding the total number of urological complications in the rhBMP-2 group versus the control group (22% vs 20%, respectively; p = 1.0) or for retrograde ejaculation specifically (8% vs 8%, respectively; p = 1.0).

CONCLUSIONS

In this study, the use of rhBMP-2 with ALIF surgery was not associated with an increased incidence of urological complications and retrograde ejaculation when compared with control ALIF without rhBMP-2. Further prospective analyses that specifically look at these complications are warranted.

Retrograde ejaculation after anterior lumbar interbody fusion with and without bone morphogenetic protein-2 augmentation: a 10-year cohort controlled study

BACKGROUND CONTEXT

Retrograde ejaculation (RE) is a complication of anterior lumbar interbody fusion (ALIF) techniques. Most commonly, this results from mechanical or inflammatory injury to the superior hypogastric plexus near the aortic bifurcation. Bone morphogenetic protein-2 (BMP-2) has been used in spinal fusions and has been associated with inflammatory and neuroinflammatory adverse reactions, which may contribute to RE development after anterior lumbar surgery.

PURPOSE

While controlling for anterior approach technique, we compared the incidence of RE with and without rhBMP-2 exposure, in large, matched cohorts of patients after ALIF.

STUDY DESIGN

Retrospective analysis of 10 years of prospectively gathered outcomes data on consecutive-patient cohorts having the same anterior exposure technique for ALIF with and without rhBMP-2 use.

PATIENT SAMPLE

All male patients without baseline sexual incapacity and having ALIF for lumbar spondylosis or spondylolisthesis of the lowest one or two lumbar levels with and without rhBMP-2, from 2002 through 2011.

OUTCOME MEASURES

Diagnosis of RE as a new finding after ALIF compared against BMP-2 exposure, comorbid conditions, and other urological complications after ALIF surgery.

METHODS

From the comprehensive surgical database at a high volume, university practice, male subjects having ALIF at one (L5/S1) or two levels (L4/5, L5/S1) from 2002 to 2011 were identified. Baseline comorbid factors, postoperative urinary catheter/retention events, and RE events were recorded and comparative incidence compared.

RESULTS

There were four consecutive-patient cohorts identified: one before rhBMP-2 use was adopted (n=174), two cohorts in which BMP-2 use was routine (n=88 and n=151), and one final cohort after BMP-2 use was discontinued from routine use (n=59). The cohorts with and without BMP-2 exposure were closely comparable for age, approach, levels of surgery, comorbid factors affecting RE. Of 239 patients with ALIF and exposure to BMP-2, RE was diagnosed in 15 subjects (6.3%), compared with an RE diagnosis rate of two of 233 control patients without BMP-2 exposure (0.9%; p=.0012). Urinary retention after bladder catheter removal was also more frequently observed in patients exposed to BMP-2 (9.7%) compared with control patients (4.6%; p=.043). Of the baseline comorbid factors, medical or surgical treatment for prostatic hypertrophy disease was associated with an increased risk of RE in the BMP-2 patients (p=.034).

CONCLUSIONS

This study confirms previous reports of a higher rate of RE in ALIF procedures using rhBMP-2 and an open anterior approach to the spine. This effect may be associated with an increased risk of postoperative urinary retention after BMP-2 exposure. The magnitude of the RE effect may be increased with concomitant prostatic disease treatments.

Retrograde ejaculation after anterior lumbar interbody fusion using rhBMP-2: a cohort controlled study

BACKGROUND CONTEXT

The commercially available growth factor recombinant bone morphogenic protein-2 (rhBMP-2) used in spinal fusion has been associated with numerous adverse reactions, including inflammatory reactions in soft tissue, heterotopic bone formation, radiculitis, osteolysis, and cage or graft subsidence. The original Food and Drug Administration Summary of anterior lumbar interbody fusion (ALIF) reported 12 retrograde ejaculation (RE) events (8%) in the rhBMP-2 groups compared with (1.4%) in the control group. It had been debated whether this finding was related to rhBMP-2 use.

PURPOSE

To compare the incidence of RE after ALIF in patients with and without rhBMP-2 use.

STUDY DESIGN

Retrospective analysis of prospectively gathered outcomes data on consecutive subjects having ALIF with and without rhBMP-2 use.

PATIENT SAMPLE

Male patients with lumbar spondylosis or spondylolisthesis having ALIF of the lowest one or two lumbar levels with and without rhBMP-2.

OUTCOME MEASURE

Report of RE as a new finding after ALIF.

METHODS

From the comprehensive outcome database at a high-volume university practice, male subjects having ALIF for one- (L5/S1) or two-level (L4/L5, L5/S1) lumbar fusion were identified. Retrograde ejaculation events were recorded and comparative incidence compared.

RESULTS

The two groups were comparable for age and additional procedures performed. There were 69 L5/S1 ALIFs performed with rhBMP-2 and 174 ALIFs performed without rhBMP-2 during the study period. Of those, 24 and 64 were two-level ALIFs performed with and without rhBMP-2, respectively. There were five RE events (7.2%) reported in the rhBMP-2 group and 1 (0.6%) in the control group. Comparing single-level L5/S1 ALIF, there was a 6.7% and 0% rate of RE in the rhBMP-2 versus control groups, respectively. At 1 year after surgery, three of six affected subjects reported resolution of the RE.

CONCLUSION

This study confirms previous reports of a higher rate of RE in ALIF procedures using rhBMP-2. This may be an important consideration in subjects concerned with sterility after surgery.

A critical review of recombinant human bone morphogenetic protein-2 trials in spinal surgery: emerging safety concerns and lessons learned

BACKGROUND CONTEXT

Increasingly, reports of frequent and occasionally catastrophic complications associated with use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in spinal fusion surgeries are being published. In the original peer review, industry-sponsored publications describing the use of rhBMP-2 in spinal fusion, adverse events of these types and frequency were either not reported at all or not reported to be associated with rhBMP-2 use. Some authors and investigators have suggested that these discrepancies were related to inadequate peer review and editorial oversight.

PURPOSE

To compare the conclusions regarding the safety and related efficacy published in the original rhBMP-2 industry-sponsored trials with subsequently available Food and Drug Administration (FDA) data summaries, follow-up publications, and administrative and organizational databases.

STUDY DESIGN

Systematic review.

METHODS

Results and conclusions from original industry-sponsored rhBMP-2 publications regarding safety and related efficacy were compared with available FDA data summaries, follow-up publications, and administrative and organizational database analyses.

RESULTS

There were 13 original industry-sponsored rhBMP-2 publications regarding safety and efficacy, including reports and analyses of 780 patients receiving rhBMP-2 within prospective controlled study protocols. No rhBMP-2-associated adverse events (0%) were reported in any of these studies (99% confidence interval of adverse event rate <0.5%). The study designs of the industry-sponsored rhBMP-2 trials for use in posterolateral fusions and posterior lateral interbody fusion were found to have potential methodological bias against the control group. The reported morbidity of iliac crest donor site pain was also found to have serious potential design bias. Comparative review of FDA documents and subsequent publications revealed originally unpublished adverse events and internal inconsistencies. From this review, we suggest an estimate of adverse events associated with rhBMP-2 use in spine fusion ranging from 10% to 50% depending on approach. Anterior cervical fusion with rhBMP-2 has an estimated 40% greater risk of adverse events with rhBMP-2 in the early postoperative period, including life-threatening events. After anterior interbody lumbar fusion rates of implant displacement, subsidence, infection, urogenital events, and retrograde ejaculation were higher after using rhBMP-2 than controls. Posterior lumbar interbody fusion use was associated with radiculitis, ectopic bone formation, osteolysis, and poorer global outcomes. In posterolateral fusions, the risk of adverse effects associated with rhBMP-2 use was equivalent to or greater than that of iliac crest bone graft harvesting, and 15% to 20% of subjects reported early back pain and leg pain adverse events; higher doses of rhBMP-2 were also associated with a greater apparent risk of new malignancy.

CONCLUSIONS

Level I and Level II evidence from original FDA summaries, original published data, and subsequent studies suggest possible study design bias in the original trials, as well as a clear increased risk of complications and adverse events to patients receiving rhBMP-2 in spinal fusion. This risk of adverse events associated with rhBMP-2 is 10 to 50 times the original estimates reported in the industry-sponsored peer-reviewed publications.

Complications of anterior lumbar surgery

The incidence of anterior lumbar surgery is increasing. Although adverse events are uncommon, several have been described. Complications can be categorized based on the time of occurrence (ie, intraoperative, postoperative), patient positioning, surgical exposure, and spinal procedure. Notable approach-related complications involve vascular, visceral, and neural structures. Abdominal complications have been reported. Clinically significant complications related to spinal decompression and reconstruction consist primarily of neurologic injuries and graft- and device-related problems. The rate of complications is higher in the setting of revision anterior surgery than with initial anterior lumbar surgery. A thorough understanding of the complications associated with anterior lumbar surgery will aid in prevention, recognition, and management of these rare problems. The assistance of a vascular, neurologic, or general surgeon may be helpful in avoiding or effectively managing complications.

Anterior Thoracolumbar Corpectomies: Approach Morbidity With and Without an Access Surgeon

BACKGROUND:

Anterior approaches for thoracolumbar corpectomies can have significant morbidity. Spine surgeons have historically performed their own anterior approaches, but recently access surgeons are being used more frequently.

OBJECTIVE:

To evaluate the morbidity rates of approaches performed by an access surgeon and by an approach-trained spinal neurosurgeon.

METHODS:

From 2004 to 2008, 46 patients undergoing anterior thoracolumbar corpectomies (levels T2-L5) by the senior author (D.C.) were identified and subdivided into 2 groups based on whether an access surgeon was involved. Nine patients were excluded, leaving 37 patients in the final analysis. Blood loss, operative times, length of hospital stay, complications, and neurological outcomes were evaluated.

RESULTS:

Eighteen patients had anterior spinal access by an approach-trained spinal neurosurgeon, and 19 patients underwent the approach by an access surgeon. Surgeries performed by the spinal neurosurgeon alone were comparable to those performed by an access surgeon with respect to operative time, days spent in the hospital, blood loss, complication rates, and improvement in neurological function.

CONCLUSION:

There appears to be no increased morbidity of anterior approaches performed by an approach-trained spinal neurosurgeon compared with approaches performed by an access surgeon in terms of operative time, complication rate, and improvement in neurological function.

Robot-assisted anterior lumbar interbody fusion in a Swine model in vivo test of the da vinci surgical-assisted spinal surgery system

STUDY DESIGN

the use of the da Vinci Surgical System to perform an anterior lumbar interbody fusion in a swine model to identify the technical properties, processes, merits, demerits, and limitations of a video-assisted robotic surgical system.

OBJECTIVE

this study was designed to demonstrate the feasibility of using a robotic surgical system to perform spinal surgery.

SUMMARY OF BACKGROUND DATA

video-assisted laparoscopic anterior fusion was first reported in 1995 and afterward was spotlighted for several years. However, this technique has not become popular because of technical difficulties and complications associated with video-assisted procedures on the spine. As such, there is a demand for investigations to improve this technology. The da Vinci Surgical System provides 3-dimensional visualization as well as uniquely dexterous instruments that are remarkably similar to human hands. Video-assisted surgery with the da Vinci Surgical System robot has already provided great value to the fields of urology, cardiology, gynecology, and general surgery over the last decade. Preclinical studies for application of this system in spinal surgery have recently been conducted.

METHODS

a pig underwent anterior lumbar interbody fusion using da Vinci Surgical System assistance, with Tyche expandable cages used for preparation of endplates and cage placement. The setup time, operation time, amount of bleeding, and the number of complications associated with robotic manipulation were recorded. Before euthanasia, the animal underwent radiologic examination to confirm proper placement of cages.

RESULTS

the total duration of the procedure took 6 hours, with some complications related to frozen armsand robotic arm collision. Even so, there was neither any significant nerve or vessel injury nor peritoneal organ damage. Furthermore, radiologic assessment confirmed proper position of the cage in the center of the disc space.

CONCLUSION

use of the da Vinci Surgical System to perform an anterior spinal procedure was shown to be safe and effective in a swine animal model. The utilization of this advanced technology shows promise to reduce the incidence of complications compared with other approaches. It requires further testing in animal models and cadavers, along with serial comparisons to current procedures.

Approach-related lesions of the sympathetic chain in anterior correction and instrumentation of idiopathic scoliosis

During anterior scoliosis instrumentation with a dual-rod system, the vertebrae are dissected anterolaterally. After surgery, some patients report a change in temperature perception and perspiration in the lower extremities. Sympathetic lesions might be an explanation for this. The aim of this clinical study was to investigate sympathetic function after anterior scoliosis instrumentation. A total of 24 female patients with idiopathic scoliosis (mean age at follow-up, 23.8 years) who had undergone anterior instrumentation on average 6.6 years earlier were included. Due to the suspected relevance of the sympathetic L2 ganglion, two groups were created: a T12 group, in which instrumentation down to T12 was carried out (n = 12), and an L3 group, in which instrumentation down to L3 was done (n = 12). Sympathetic function was assessed by measuring skin temperature at the back of the foot, a plantar ninhydrin sweat test and sympathetic skin responses (SSRs) following electrical stimulation. The side on which the surgical approach was carried out was compared with the contralateral, control side. Health-related quality of life was investigated using the Scoliosis Research Society SRS-22 patient questionnaire. In the T12 group, mean temperatures of 29.6 degrees C on the side of the approach versus 29.5 degrees C on the control side were measured (P > 0.05); in the L3 group, the mean temperatures were 33.2 degrees C on the approach side versus 30.5 degrees C on the control side (P = 0.001). A significant difference between the T12 group and the L3 group (P < 0.001) was observed on the approach side, but not on the control side (P = 0.15). The ninhydrin sweat test showed reduced perspiration in 11 of 12 patients in the L3 group on the approach side in comparison with the control side (P = 0.002). In the T12 group, no significant differences were noted between the left and right feet. SSRs differed significantly between the two groups (P = 0.005). They were detected in all nine analyzable patients in the T12 group on both sides. In the L3 group, they were found on the approach side only in 4 of 11 analyzable patients versus 11 patients on the control side. The results of the SRS-22 questionnaire did not show any significant differences between the two groups. In conclusion, anterior scoliosis instrumentation with a dual-rod system including vertebrae down to L3 regularly leads to lesions in the sympathetic trunk. These are detectable with an increase in temperature, reduced perspiration and reduced SSRs. The caudal level of instrumentation (T12 vs. L3) has an impact on the extent of impairment, supporting the suspected importance of the L2 ganglion. The clinical outcome does not seem to be significantly limited by sympathetic trunk lesions.

Which lumbar interbody fusion technique is better in terms of level for the treatment of unstable isthmic spondylolisthesis?

OBJECT

The purpose of this study was to investigate and compare clinical and radiographic outcomes of 2 kinds of lumbar interbody fusion (LIF) for the treatment of adult low-grade isthmic spondylolisthesis at L4-5 and L5-S1 levels.

METHODS

The medical records and radiographs of 86 patients who underwent anterior LIF (ALIF) (L4-5, 42 patients; L5-S1, 44 patients) and 42 patients who underwent transforaminal LIF (TLIF) (L4-5, 22 patients; L5-S1, 20 patients) between 2001 and 2004 were retrospectively reviewed. Clinical results were investigated using the visual analog scale (VAS) and Oswestry Disability Index (ODI) scores, and using radiographic measurements, including disc height (DH), degree of spondylolisthesis, segmental lordosis, whole lumbar lordosis (WL), sacral slope (SS), and pelvic tilt; the L-1 axis S-1 distance (LASD) and pelvic incidence were also obtained.

RESULTS

In both groups, VAS and ODI scores had significantly improved at both treatment levels. Statistical analysis showed no significant difference in postoperative VAS scores between groups at the L4-5 level and in postoperative VAS/ODI scores at the L5-S1 level. However, ODI scores were better in the TLIF than in the ALIF group at the L4-5 level. In terms of radiological changes, there were no significant differences between the 2 groups at the L4-5 level; however, at the L5-S1 level, radiographic results indicated that ALIF was superior to TLIF in its capacity to restore DH, WL, SS, and LASD. The radiological evidence of fusion shows no intergroup difference and no interlevel difference.

CONCLUSIONS

Considering the clinical and radiological outcomes in both groups, the authors recommend that instrumented mini-TLIF is preferable at the L4-5 level, whereas instrumented mini-ALIF might be preferable at the L5-S1 level for the treatment of unstable isthmic spondylolisthesis.