Anterior Lumbar Surgery Research Articles

An Update in Complication Rates Associated With Anterior Lumbar Surgery: A Systematic Review and Meta-Analysis.

Systematic Review and meta-analysis. To conduct an updated systematic review and meta-analysis of complications associated with different anterior fusion techniques/approaches and adjuvant resources (i.e., computed tomography angiography (CTA), rhBMP-2, and access surgeons). A systematic review was conducted from 1/1/2014-4/1/2024 for studies evaluating the incidence of complications associated with anterior lumbar procedures. Comparisons of complications were made between surgical approach, use of CTA, rhBMP-2, and access surgeons. Meta-analyses were conducted using a generalized linear mixed model. 54 studies were included in the final analysis with 8066 patients and an average follow-up of 31.2 months. The overall complication rate associated with anterior lumbar surgery was 13.1%, including an intraoperative complication rate of 3.8%, postoperative complication rate of 7.4%, infection rate of 1.5%, and reoperation rate of 1.7%. Forest plot analysis showed no significant difference in overall complication rates between open and mini-open techniques, although mini-open techniques were associated with lower overall reoperation rates. The use of CTA was associated with an increase in intraoperative and overall complications, and the use of an access surgeon was associated with a decreased risk of reoperation. The use of rhBMP-2 was not associated with overall complication risk. While anterior lumbar surgery provides numerous benefits, surgeons and patients alike should be aware of the complication and safety profile prior to surgery. High quality studies are warranted to help elucidate the true benefit of certain techniques and adjuvant resources in reducing complications.

Prospective Analysis of Incisional Morbidity Associated With Anterior Surgical Approaches to the Lumbar Spine.

Anterior approaches to the lumbar spine have been used extensively for various indications but they are also associated with unique complications and have been linked with higher incisional morbidity.This study aimsto evaluate incisional morbidity related to anterior lumbar surgeries and to assess how incisional outcomes correlate with patient and surgery-related factors. Patients ≥18 years old and with planned anterior lumbar fusions from L1 to S1 were prospectively enrolled. Follow-up ended at two years, and patients who did not complete the follow-upwere excluded. Incision was assessed for general appearance, width, color, cross-hatching, hypertrophy, and pain by using a validated scoring system and a visual analog scale (VAS). Patient and surgery-related factors were analyzed for possible correlations with complications or wound-related parameters. A total of 205 patients with a mean age of 54.4 ± 11.5 were included. Significant improvements were seen in color, hypertrophy, pain, and appearance of the incision. At two years, the mean patient-based VAS for appearance was 8.6 while surgeon-based VAS was 8.8. The total rate of complications was 9%, with no incisional hernia or bulging. No significant relation was found between incision-related parameters and the demographic and surgical variables. This study reports acceptable cosmetic results and no chronic pain after anterior lumbar surgery, which is contrary to previous reports. Together with a low total rate of complications, anterior approaches are safe when carefully executed, and have low morbidity.

An updated classification of the anatomical variations of the internal iliac venous drainage system: Surgical implications for anterior lumbar spinal approaches

BackgroundAdvanced pelvic surgery is associated with potential vascular risks. The aim of this study was to complete the existing classification of the anatomical variations of the internal iliac veins encountered on a series of preoperative angio CT with a view to performing anterior lumbar spine surgery. Materials and MethodsIn this monocentric retrospective study conducted between 2010 and 2020, all preoperative angio CT performed before an anterior lumbar surgery were systematically analyzed. All the abnormalities of the iliac veins were referenced in an updated classification system. Results910 patients (431 men and 479 women) with a mean age of 49 years [16–88] were included. Apart from the most common variant in the population (type I), 64 anatomical variations (7.0%) in the iliac veins were reported and classified according to our new classification. The percentage of coverage of the L4-L5 intervertebral disc is 52%, including 32% by the inferior vena cava before the confluence of the common iliac veins. At the level of the L5-S1 intervertebral disc, the coverage is 30% (same distribution between left and right). ConclusionsVariations of the iliac veins are frequent, and contrary to what one might think, and even if they can represent an anatomical trap during surgery, certain variations do not limit anterior lumbar spine surgery and are not more associated with vascular complications. Nevertheless, these anatomical variations must be known before any advanced pelvic surgery. Depending on their distribution, level L5-S1 is more suitable for ALIF, level L4-L5 for OLIF approaches.

Pneumocephalus After Anterior Lumbar Spinal Surgery Due to Trauma: A Case Report

Pneumocephalus as a complication of anterior lumbar spinal surgery is extremely rare. A 53-year-old male patient presented with L4 fracture. Posterior fixation from L3 to L5 was conducted one day after the trauma. As the patient’s neurological deficit persisted, additional anterior surgery by L4 vertebral body replacement was performed on the 19th day. Both surgeries were completed without obvious intraoperative complications. Two weeks after the anterior lumbar surgery, the patient complained of severe headaches, and computed tomography scan revealed pneumocephalus and massive fluid retention in the abdomen. The symptoms improved with conservative treatment, including bed rest, spinal drainage, intravenous drip infusion, and prophylactic administration of antibiotics. Due to the lack of tamponade effect in the soft tissues, a large amount of cerebrospinal fluid leakage may induce and cause progression of pneumocephalus in anterior dural injury.

Who bleeds during elective anterior lumbar surgery?

BackgroundBlood loss (BL) during elective anterior lumbar access for interbody fusion or disc replacement is a potentially major complication. This study sought to identify factors other than major vascular injury which contribute to BL and therefore this risk. Factors suggested to effect blood loss include age, increasing body mass index (BMI), sex, prothesis, intraoperative heparinization and continuation of low-dose aspirin (LD-ASA). MethodsA Cell Saver was used in all cases with BL measured and recorded by an independent autotransfusionist. Heparin was administered intravenously when one or both of 2ndtoe saturation metre signal/s lost pulsatility indicating lower limb arterial flow was interrupted. ResultsThe mean age of the 364 patients was 47 ± 13.2 yrs. [95% CI: 45 – 48]; and 191 (52%) were male. Age, BMI and heparinization showed a positive correlation with increased BL. There was no significant association with continuation of low-dose ASA with increased BL. Most patients underwent an ALIF - 265 (72%), 52 (14%) had a TDR, and 47 (13%) had a hybrid operation. There was a significant increase in mean BL between single- and two-level procedures in the non-heparinised group (48 vs 83 mls, p = 0.003). Intraoperative heparinization was administered in 102 patients (28%). The total mean BL for the heparin group (104 ml) which was significantly higher than for the non-heparin group (53 ml) (p = 0.001). Heparinisation did not significantly increase the mean BL in single or double level ALIF patients but did significantly increase the BL in single level TDR (57 vs 151 mls, p = 0.039). ConclusionsYounger, leaner, non-heparinized, single level ALIF patients represented the lowest bleeding risk in anterior lumbar surgery. Conversely, older, increasing BMI, two operative levels, TDR prosthesis and heparinization represent the highest bleeding risk. Continuation of LD-ASA was not associated with an increase in BL.

180. Who bleeds during elective anterior lumbar surgery?

<h3>BACKGROUND CONTEXT</h3> Blood loss during elective anterior lumbar access for interbody fusion or disc replacement is a potentially major complication. Patients undergoing this surgery have a variety of co-morbidities and medication which may contribute. <h3>PURPOSE</h3> The aim of this study was to examine which factors effect intraoperative estimated blood loss (EBL) during anterior lumbar surgery. <h3>STUDY DESIGN/SETTING</h3> A prospective study of consecutive anterior retroperitoneal approaches for lumbar surgery was performed between January 2010 and November 2021, by a single vascular surgeon and a single spine surgeon. <h3>PATIENT SAMPLE</h3> All patients (n=368) underwent an anterior lumbar interbody fusion (ALIF) at L4–5 and/or L5–S1, a total disc replacement (TDR) at L4–5 and/or L5–S1, or a hybrid procedure with a TDR at L4–5 and an ALIF at L5–S1. <h3>OUTCOME MEASURES</h3> We examined the effects of patient age, sex, body mass index (BMI), low-dose aspirin (LD-ASA), operative level, prosthesis and intraoperative heparinization. <h3>METHODS</h3> The Cell Saver was used in all cases with blood loss measured and recorded by an independent autotransfusionist. Saturation probes were placed on the second toes bilaterally. Heparin was administered intravenously when the saturation meter signal lost pulsatility indicating lower limb arterial flow was interrupted. <h3>RESULTS</h3> The mean age of the 368 patients was 47 ± 13.2 yrs [95% CI = 45 – 48]; and 210 (57%) were male. BMI showed a negative association with EBL. Age showed no effect on EBL in non-heparinized patients but a negative trending correlation with EBL in heparinized patients. Continuation of LD-ASA did not significantly affect EBL. Most patients underwent an ALIF (265 patients,72%), 55 (15%) had a TDR, and 48 (13%) had a hybrid operation (with a TDR at L4–5 and an ALIF at L5–S1) and the majority (249 patients,68%) had a single-level procedure (54 (26.9%) at L4–5 and 195 (73.1%) at L5–S1) and 119 (32%) underwent a 2-level procedure (L4–5 and L5–S1). There was more than twice mean EBL with TDR (135ml) and hybrid (104ml) compared to ALIF (59ml) but were not statistically significant. Intraoperative heparinization was administered in 104 patients (28%). The total mean EBL for the heparin group (125ml) was significantly higher than for the non-heparin group (56ml) (p< 0.0004). A significant difference was observed when comparing heparin vs nonheparin patients and the procedure type. With ALIF (p < 0.002), TDR (p< 0.03) and hybrid (p< 0.02) there was a significantly higher EBL with heparinized patients compared to nonheparinized patients. <h3>CONCLUSIONS</h3> TDR showed the highest EBL across procedure types. In non-heparinized patients, older age, increasing BMI and continuation of LD-ASA were not predictors for increased EBL. However, in heparinized patients, age and BMI showed a negative correlation with increased EBL. This study suggested younger, leaner, heparinized patients who undergo TDR surgery demonstrated the highest EBL risk in anterior lumbar surgery. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Standalone titanium/polyetheretherketone interbody cage for anterior lumbar interbody fusion: Clinical and radiological results at 24 months.

Context:Anterior lumbar interbody fusion (ALIF) is a common procedure for patients suffering degenerative, deformity, or posttraumatic pathologies of the lumbar spine.Aims:The aim of this study is to evaluate the clinical and radiological outcomes of a combination Titanium/Polyetheretherketone (Ti/PEEK) 3-screw fixation ALIF cage.Settings and Design:This was a prospective multisurgeon series of 87 patients (105 implants), with a minimum 24-month follow-up. Twelve patients (12/87) were supplemented with posterior percutaneous pedicle screw fixation for additional stability for pars defect spondylolisthesis correction. Radiological follow-up with fine-cut computed tomography (CT) scan occurred at 4–6 months, and again at 18–24 months if no fusion observed on initial CT, was performed to evaluate early and final fusion rates, and integration of the Ti/PEEK cage at the end-plate junction. Clinical follow-up included the subjective measures of pain and functional status and objective wearable device monitoring.Results:The fusion rate was 85% (97/105 implants) 6 months postoperatively, with no implant-related complications, and 95% at 24 months, based on independent radiological assessment. Patients experienced statistically significant improvement in subjective pain and functional outcomes compared to preoperative status. The objective measures revealed a daily step count with a 27% improvement, and gait velocity with a mean increase from 0.97 m/s to 1.18 m/s, at 3 months postoperatively.Conclusions:A Ti/PEEK cage, with allograft and bone morphogenetic protein-2 (BMP-2), achieved rapid interbody progression to fusion and is an effective implant for use in anterior lumbar surgery with high early fusion rates and no peri-endplate lucency. Supercritical CO2 allograft provided an osteoconductive scaffold and combined well with BMP-2 to facilitate fusion.

Vascular Injury in Elective Anterior Surgery of the Lumbar Spine: A Narrative Review.

The incidence of anterior lumbar surgery is increasing as the population is aging. Although adverse events regarding vasculature injury are uncommon, several have been described in the current literature. Complications can be categorized based on the time of occurrence, more specifically intraoperative or postoperative, but also regarding the nature of vascular damage such as thrombosis, occlusion, or rupture. The rate of complications is higher in the setting of revision anterior surgery than with primary anterior lumbar surgery. Moreover, the incidence of revision anterior surgery is also increasing in contrast to the past. Through this narrative review, an effort is made for a thorough understanding of the complications associated with anterior lumbar surgery, which will aid in the prevention, recognition, and management of this rare complication.

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

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. 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. 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. 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.

Outpatient Versus Inpatient Anterior Lumbar Spine Surgery: A Multisite, Comparative Analysis of Patient Safety Measures.

The frequency and complexity of spinal surgery performed in an ambulatory surgery center (ASC) is increasing. However, safety and efficacy data of most spinal procedures adapted to the ASC are sparse and have focused on anterior cervical surgery. The purpose of this study was to compare the 90-day complication and readmission rates of anterior lumbar spine surgery performed in an ASC or inpatient setting. We performed a retrospective comparative analysis of 226 consecutive anterior lumbar surgeries (283 levels treated) completed in an ASC (n = 124) or in an inpatient tertiary care hospital (n = 102) over a 3-year period. These included anterior lumbar interbody fusion (ALIF), artificial disc replacement (ADR), and hybrids. Patients undergoing simultaneous or staged posterior procedures within 3 months were excluded. Patient demographics and surgical parameters between the two surgical settings were compared. Ninety-day medical complications and readmission rates were assessed. One-way analysis of variance and Chi-square analysis were used. A P value of less than .05 was considered statistically significant. The two study groups had similar baseline characteristics. While there was a trend toward fewer complications, reoperations, and readmissions for the ASC cohort, the differences were not statistically significant. There were 7 intraoperative complications (5.6% minor vascular injury) in the inpatient cohort and 0 in the ASC cohort. The overall 90-day postoperative complication rate was 5.6% for the inpatient cohort and 0.9% for the ASC cohort. The 90-day readmission rate was 1.9% in the ASC cohort and 1.6% in the inpatient cohort. The 90-day reoperation rate was 0.8% for the inpatient cohort and 0% in the ASC cohort. The average hospital stay was 2.3 ± 1.5 days for the inpatient cohort. The 90-day readmission rates were lower for outpatients than for inpatients, while the complication and reoperation rates were similar. Our results demonstrate that anterior lumbar procedures, including single-level and multilevel ALIF, ADR, and hybrid procedures, can be performed safely in an ASC. This has significant cost savings implications for the ASC setting.

Post-operative radiculitis following one or two level anterior lumbar surgery with or without posterior instrumentation

The purpose of this study was to define risk factors for non-compression radiculitis following anterior lumbar surgery with or without posterior instrumentation and to define a time to resolution. In this study, we followed 58 consecutive patients who had anterior lumbar surgery with or without posterior instrumentation. We identified those with and without post-operative radiculitis. There as a 36.5% rate of postoperative radiculitis. We found that there was a moderate to strong correlation with height change and radiculitis (p = 0.044). Additionally patients treated with rh-BMP2 had a higher risk of developing symptoms. In all of the patients who developed postoperative radiculitis, symptoms resolved by 3 months. In conclusion 36.5% of patients developed post operative radiculitis. This was associated with the use of rh-BMP2, as well as increasing disc height through surgery. All symptoms resolved by 3 months posoperatively.

150. Outpatient vs inpatient anterior lumbar surgery: a multisite, comparative analysis of patient safety measures

BACKGROUND CONTEXT The frequency and complexity of spinal surgery performed in an outpatient setting has been steadily increasing in the past decade. However, data on the safety and efficacy of most spinal procedures adapted to the outpatient setting is lacking. The few studies that have reviewed specific outpatient procedures have mostly focused on anterior cervical surgery, and have drawn conflicting conclusions. To our knowledge, there is no published literature on the feasibility, safety and effectiveness of anterior lumbar surgery (fusions and disc replacements) in an outpatient setting. PURPOSE The purpose of this study is to evaluate the safety and efficacy of outpatient anterior lumbar procedures compared to procedures done at an inpatient setting in a matched cohort of patients. STUDY DESIGN/SETTING This study is a retrospective matched cohort study of patients who underwent an anterior lumbar interbody fusion (ALIF) or a lumbar artificial disc replacement (LADR) at an inpatient facility, compared to a free-standing ambulatory surgery center. PATIENT SAMPLE Consecutive adult patients of several orthopedic and neurosurgical spine surgeons, who underwent elective stand-alone ALIF or LADR or a hybrid of fusion and disc replacement, at either an inpatient tertiary care facility or an outpatient surgical center were studied. A minimum of 90-day follow-up was required. OUTCOME MEASURES Reoperation rates, readmission rates, 90-day complication rates, and length-of-stay data were collected and compared between the two groups. Complications that were specifically assessed included neurological injury, durotomy, vascular injuries, bowel injuries, postoperative ileus, epidural or retroperitoneal hematomas, postoperative urinary retention, urinary tract infections, deep vein thrombosis (DVT), pulmonary embolism (PE), cardio-pulmonary complications, intractable pain, surgical site infection, and death. METHODS Medical records of 231 consecutive patients who underwent ALIF or LADR procedures between 2016-2019 were reviewed. The inpatient and outpatient cohorts were matched with regards to age, sex, body mass index (BMI), and medical comorbidities. Length of stay, complication data, reoperations, and readmissions were recorded and compared between the groups. RESULTS A total of 124 (54%) inpatient and 107 (46%) outpatient patients were reviewed for this study. The two groups had similar baseline characteristics. While there was a trend toward fewer complications, reoperations and readmission for the outpatient cohort, the differences were not statistically significant. The overall 90-day complication rate was 5.6% for the inpatient cohort, and 0.9% for the outpatient cohort. Of the patients in the inpatient cohort, 3.2% were re-admitted within 90 days, compared to 1.9% of those in the outpatient cohort. Reoperation rate was 1.6% for the inpatient cohort. No patient from the outpatient cohort required reoperation. The average hospital stay was 56.9 hours, compared to 5.2 hours at the ambulatory surgery center. CONCLUSIONS There were no statistically significant differences between the 90-day complication and reoperation rates between anterior lumbar procedures performed in an inpatient vs outpatient setting in a matched cohort of patients. Furthermore, the overall 90-day readmission rates were lower for outpatients than for inpatients. Our results support the conclusion that anterior lumbar procedures including 1- and 2-level ALIF and LADR procedures can be performed safely in an outpatient setting. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Impact of resident involvement on cervical and lumbar spine surgery outcomes

BACKGROUND CONTEXTResident involvement in the operating room is a vital component of their medical education. Conflicting and limited research exists regarding the effects of surgical resident participation on spine surgery patient outcomes. PURPOSETo determine the effect of resident involvement on surgery duration, length of hospital stay and 30-day postoperative complication rates in common spinal surgery using the American College of Surgeons’ National Surgical Quality Improvement Program (ACS-NSQIP) database. STUDY DESIGNMulticenter retrospective cohort study. PATIENT SAMPLEA total of 1,441 patients met the inclusion criteria: 1,142 patients had surgeries with an attending physician alone and 299 patients had surgeries with trainee involvement. All anterior cervical or posterior lumbar surgery patients were identified. Patients who had missing trainee involvement information, surgery for cancer, preoperative infection or dirty wound classification, spine fractures, traumatic spinal cord injury, intradural surgery, thoracic surgery, and emergency surgery were excluded. OUTCOME MEASURESThe main outcomes of interest analyzed from the ACS-NSQIP database included surgical complications, medical complications, length of hospital stay, and surgery duration. METHODSPropensity score for risk of any complication was calculated to account for baseline characteristic differences between the attending alone and trainee present group. Multivariate logistic regression was used to investigate the impact of resident involvement on surgery duration, length of hospital stay, and 30-day postoperative complication rates. RESULTSAfter adjusting using the calculated propensity score, the multivariate analysis demonstrated that there was no significant difference in any complication rates between surgeries involving trainees compared to surgeries with attending surgeons alone. Surgery times were found to be significantly longer for surgeries involving trainees. To further explore this relationship, separate analyses were performed for tertiles of predicted surgery duration, cervical or lumbar surgery, fusion or nonfusion, and inpatient or outpatient surgery. The effect of trainee involvement on increasing surgery time remained significant for medium predicted surgery duration, longer predicted surgery duration, cervical surgery, lumbar surgery, fusion surgery, and inpatient surgery. There were no significant differences reported for any other factors. CONCLUSIONSAfter adjusting for confounding, we demonstrated in a national database that resident involvement in surgeries did not increase complication rates. We demonstrated that surgeries with more complex features may lead to an increase in operative time when trainees are involved. Further study is required to determine how to efficiently integrate resident involvement in surgeries without affecting their medical education.

Sexual and urinary function following anterior lumbar surgery in females.

Anterior lumbar interbody fusion procedures (ALIF) and total disc replacement (TDR) with anterior exposure of the lumbar spine entail a risk of a vascular injury and dysfunction of the sympathetic and parasympathetic nerves due to disturbance of the inferior and superior hypogastric plexus. While retrograde ejaculation is a known complication of the anterior spinal approach in males, post-operative sexual as well as urinary function in females has not yet been thoroughly investigated and was hence the aim of this study. Fifteen female patients documented their sexual and urinary function preoperatively, 3 months and 6 months postoperatively, using the validated questionnaires FSFI (Female Sexual Function Index) and ICIQ (International Consultation of Incontinence Questionnaire). Randomization tests were used to statistically analyze expectation values over time (two-sided, P < 0.05). While no statistically significant change in the total FSFI score occurred over time, a significant increase in FSFI desire score was noted between preoperative (2.95 ± 0.8) and 6 months follow-up (3.51 ± 0.6, P = 0.02). Urinary continence remained unchanged over time. In summary, ALIF and lumbar TDR do not seem to negatively influence sexual and urinary function in females. In contrast, increased sexual desire was noted, likely secondary to post-surgical pain relief.

Iatrogenic Bowel Injury Following Minimally Invasive Lateral Approach to the Lumbar Spine: A Retrospective Analysis of 3 Cases.

Study Design:Retrospective cohort study.Objective:Anterior approaches are often used during lumbar interbody fusion procedures. Visceral injuries (bowel injuries) are rare but represent a primary risk during anterior approaches to the lumbar spine. Left untreated, these injuries can result in significant complications. The aim of this study was to investigate the presentation and management of bowel injury cases following anterior approaches to the lumbar spine to raise the surgeon’s awareness of this rare complication.Methods:All direct anterior, oblique anterior, and transpsoas lumbar interbody fusion surgeries performed at our institution between 2012 and 2016 were analyzed retrospectively. Charts were screened for cases requiring return to the operating room owing to a suspected bowel injury and details of the case were extracted for illustrative purposes.Results:A total of 775 anterior lumbar surgeries were conducted at a single tertiary care institution between July 2012 and June 2017. A total of 590 transpsoas lumbar interbody fusion (TPIF) surgeries were performed. Four patients, each having undergone TPIF, were suspected of bowel injury and underwent an exploratory laparotomy. At surgery, 3 patients were confirmed to have a bowel injury, giving a procedure-specific incidence of 0.51% and overall incidence of 0.39%. Among the 3 confirmed bowel injury cases, average delay between surgery and visceral injury diagnosis was 4.7 days (range 3-7 days).Conclusions:We noted abdominal pain, distention, and fever as the most common findings in the setting of a visceral injury. A high index of suspicion and computed tomography imaging remain critical for identifying postoperative bowel injuries.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters

BACKGROUND CONTEXT Lumbar fusion surgery can be performed through either anterior, lateral or posterior approaches. Although the relative advantage of anterior lumbar surgeries for the restoration of sagittal balance in spinal deformity is well-acknowledged, the comparative utility of these approaches in maintaining sagittal alignment following single level lumbar fusion remains unclear. PURPOSE A systematic review of the current literature was performed to assess the relative change in sagittal lumbar parameters including whole lumbar lordosis (WLL), segmental lumbar lordosis (SLL) and disc height (DH) following lumbar fusion using various approaches. STUDY DESIGN/SETTING Systematic review and meta-analysis. PATIENT SAMPLE All subjects in studies reporting imaging outcomes following single-level lumbar fusion, according to inclusion and exclusion criteria. OUTCOME MEASURES Lumbar sagittal parameters (SLL and WLL) and DH. METHODS A computerized literature search of all articles published up to April 17, 2017 was performed using PubMed and Cochrane databases. The following keywords were used: “anterior lumbar interbody fusion”, “ALIF”, “posterior lumbar interbody fusion”, “PLIF”, “trans-foraminal lumbar interbody fusion”, “TLIF”, “lumbar 360° fusion”, “circumferential lumbar fusion”, “combined anterior and posterior lumbar fusion”, “extreme lateral interbody fusion”, “LLIF”, “lateral lumbar interbody fusion”, “LLIF”, “direct lateral interbody fusion”, “DLIF”, “extraforaminal lumbar interbody fusion”, “ELIF”, with different combinations of operators including “AND”, “NOT” and “OR”. All studies were scored based on Methodological Index for NonRandomized Studies (MINORS) criteria. Pairwise comparisons of the fusion approach effect sizes were performed for the three imaging parameters. RESULTS A total of 1,563 articles under “ALIF”, 2,075 articles under “PLIF”, 1,032 articles under “TLIF”, 1,082 articles under “LLIF” and 894 under “circumferential lumbar fusion” were identified. The articles were further stratified on the basis of number of fusion levels. Only studies reporting relevant imaging outcomes following single-level fusion for degenerative pathologies were included in the final analysis. Using this strategy, a total of 14, 27, 25, 11 and 3 studies were included under ALIF, PLIF, TLIF, minimally invasive-TLIF and LLIF, respectively. Based on pairwise comparisons, ALIF significantly improved WLL and DH restoration as compared to all the other fusion modalities [ALIF vs. PLIF:2.5 (0.5–4.6) vs. 1.5 (0.2–2.4), p CONCLUSIONS Based on a systematic review of the literature, ALIF offers a significantly improved restoration of lumbar sagittal parameters following single-level lumbar fusion.

Combination Ti/PEEK ALIF cage for anterior lumbar interbody fusion: Early clinical and radiological results

Anterior lumbar interbody fusion (ALIF) is a common procedure for patients with degenerative pathologies of the lumbar spine. In this study, the clinical and radiological outcomes of a combination titanium/polyetheretherketone (Ti/PEEK) ALIF cages in one, two and three-level surgery were evaluated. Over an 18-month time period, a prospective single surgeon series of 20 implants (15 patients) were included in the study, with minimum 10-months follow-up. From these 15 patients, two were supplemented with posterior percutaneous pedicle screw fixation for additional stability. Radiological follow-up with fine cut CT scan at 9–12months was performed to evaluate early fusion rates, and integration of the Titanium/PEEK cage at the endplate junction. 20 implants were followed for a minimum of 10months, and a mean of 15months. A 95% (19/20 implants) fusion rate with no implant related complications was achieved at the mean 15-month postoperative mark. Patients experienced statistically significant improvement in pain and functional outcomes (SF12 and ODI) compared to their pre-operative status. A single patient with a non-union at L5/S1 (smoker) did not experience any improvement in symptoms. A Ti–PEEK cage, with allograft and BMP-2 to achieve interbody fusion is an effective implant for use in anterior lumbar surgery with high fusion rates, no lucency around the titanium endplates at follow-up, and with promising early results.

Is Hydronephrosis a Complication after Anterior Lumbar Surgery?

Study Design Prospective follow-up design. Objective Ureteral injury is a recognized complication following gynecologic surgery and can result in hydronephrosis. Anterior lumbar surgery includes procedures like anterior lumbar interbody fusion (ALIF) and total disk replacement (TDR). Anterior approaches to the spine require mobilization of the great vessels and visceral organs. The vascular supply to the ureter arising from the iliac arteries may be compromised during midline retraction of the ureter, which could theoretically lead to ureter ischemia and stricture with subsequent hydronephrosis formation. Methods Potential candidates with previous ALIF or TDR via anterior retroperitoneal access between January 2008 and March 2012 were chosen from those operated on by a single surgeon in a university hospital setting (n = 85). Renal ultrasound evaluation of hydronephrosis was performed on all participants. Simple descriptive and inferential statistics were used to generate results. Results A total of 37 voluntary participants were recruited (23 male, 14 female subjects; average age 51.8 years). The prevalence of hydronephrosis in our population was 0.0% (95% confidence interval 0 to 8.1%). Conclusions Retraction of the ureter across the midline in ALIF and TDR does not result in an increase in hydronephrosis and appears to be a safe surgical technique.

Complications of the Anterior Approach to the Lumbar Spine

Introduction Lumbar spine pathology, such as tumors and fractures, commonly affect vertebral bodies, making anterior access to the spine an important tool in the armamentarium of spinal surgeons. Furthermore, accessing the front of the spine via a posterior approach is associated with the potential for neural injury. Reports in the literature of high rates of complications, particularly vascular injury, has led to questions about the safety of the anterior lumbar approach. As a result, various recommendations have been made such as the used of “access” surgeons and ring retractor systems to reduce the complication rate. We present the complication rates from over 550 anterior approaches performed in Exeter, United Kingdom, by multiple surgeons over an 18-year period, without the use of an access surgeon or ring retractor system. Materials and Methods We retrospectively reviewed the notes of 567 consecutive patients having undergone an anterior approach to the lumbar spine for any procedure from 1996 to 2014. Information was collected from operation notes, anesthetic records, postoperative ward rounds, and clinic letters. Details were recorded on intraoperative blood loss and complications such as vascular injury and peritoneal opening as well as postoperative complications such as infection, DVT/PE, ileus, and hernias. Results There was an overall complication rate of 13.4%. The rate of vascular injury requiring suture repair was 3.2% and the rate requiring input from a vascular surgeon 0.8%. Conclusion We report a comprehensive and critical review of our practice over 18-years with a large series of consecutive patients undergoing anterior lumbar surgery for a wide range of pathology. This has been performed in a single center by multiple orthopedic spinal surgeons without the use of access surgeons or dedicated ring retractor systems. Our complication rates have been shown to be comparable to the existing literature demonstrating that in high volume centers the anterior approach to the lumbar spine is safe and effective for a multitude of applications.

Iatrogenic Baastrup's Syndrome: A Potential Complication Following Anterior Interbody Lumbar Spinal Surgery.

Baastrup's Syndrome is a condition that occurs when there is abnormal contact between two adjacent spinous processes resulting in back pain. An alteration in lumbar spinal alignment and/or adjacent segment compensatory motion is thought to be potential causative factors. The objective of this study was to present a case series of what appears to be iatrogenic Baastrup's Syndrome as a mid-to-late term complication following anterior lumbar interbody surgery. A retrospective chart review was performed of all patients undergoing anterior lumbar surgery for either fusion or disc replacement to determine the prevalence of Baastrup's Syndrome. Over a 12-year period, 855 patients who had undergone an anterior approach for lumbar spine surgery were identified. Of them 8 patients with evidence of Baastrup's Syndrome were found; this demonstrated a prevalence of 0.9%. Diagnostic injection was a helpful clinical tool in confirming the diagnosis of iatrogenic Baastrup's Syndrome. The partial removal of the impinging spinous processes resulted in excellent clinical relief. Iatrogenic Baastrup's Syndrome may be an iatrogenic result of anterior lumbar surgery in small group of patients. Spinous process excision is a suggested treatment option. Further studies are necessary to explore the above phenomenon. This study is a Level 3 retrospective case series.