Vascular complications are an important adverse event that can be associated with spinal reconstructive surgery. Direct injury of vessels, or indirect traction or compression of vessels, can cause both arterial and venous injury. Indirect compression of the mesenteric vessels is a well-recognized complication of bracing and surgical care of children with spinal deformity (superior mesenteric artery syndrome), but the complication is not common or well recognized in the adult population with spinal deformity. The purpose of this case report is to detail the case of postoperative mesenteric ischemia in a 63-year-old man in whom a posterior approach was used to perform spinal deformity correction. Preoperatively, the patient had had significant lumbar hypolordosis. The reconstructive surgery with the use of posterior-based osteotomies resulted in a shortening of the posterior column of the spine but a relative lengthening of structures anterior to the spine. The significant lordosis achieved by the surgery led to an acute worsening of the mesenteric stenosis suffered by the patient. He required a vascular surgery intervention to restore perfusion to the bowel. Recognition of severe vasculopathy is important in anticipating potential postoperative vascular insufficiency. This case report will inform surgeons and clinicians to have a higher index of suspicion for the exacerbation of vascular insufficiency, including mesenteric pathology, in patients undergoing surgery that involves significant realignment of the spine. Preoperative recognition of vascular insufficiency and treatment of symptomatic disease may limit the occurrence of postoperative vascular complications in spinal reconstructive surgery.
Krishn Khanna and Sigurd H. Berven
John E. Ziewacz, Sigurd H. Berven, Valli P. Mummaneni, Tsung-Hsi Tu, Olaolu C. Akinbo, Russ Lyon and Praveen V. Mummaneni
The purpose of this study was to provide an evidence-based algorithm for the design, development, and implementation of a new checklist for the response to an intraoperative neuromonitoring alert during spine surgery.
The aviation and surgical literature was surveyed for evidence of successful checklist design, development, and implementation. The limitations of checklists and the barriers to their implementation were reviewed. Based on this review, an algorithm for neurosurgical checklist creation and implementation was developed. Using this algorithm, a multidisciplinary team surveyed the literature for the best practices for how to respond to an intraoperative neuromonitoring alert. All stakeholders then reviewed the evidence and came to consensus regarding items for inclusion in the checklist.
A checklist for responding to an intraoperative neuromonitoring alert was devised. It highlights the specific roles of the anesthesiologist, surgeon, and neuromonitoring personnel and encourages communication between teams. It focuses on the items critical for identifying and correcting reversible causes of neuromonitoring alerts. Following initial design, the checklist draft was reviewed and amended with stakeholder input. The checklist was then evaluated in a small-scale trial and revised based on usability and feasibility.
The authors have developed an evidence-based algorithm for the design, development, and implementation of checklists in neurosurgery and have used this algorithm to devise a checklist for responding to intraoperative neuromonitoring alerts in spine surgery.
Dominic Amara, Praveen V. Mummaneni, Christopher P. Ames, Bobby Tay, Vedat Deviren, Shane Burch, Sigurd H. Berven and Dean Chou
Many options exist for the surgical management of adult spinal deformity. Radiculopathy and lumbosacral pain from the fractional curve (FC), typically from L4 to S1, is frequently a reason for scoliosis patients to pursue surgical intervention. The purpose of this study was to evaluate the outcomes of limited fusion of the FC only versus treatment of the entire deformity with long fusions.
All adult scoliosis patients treated at the authors’ institution in the period from 2006 to 2016 were retrospectively analyzed. Patients with FCs from L4 to S1 > 10° and radiculopathy ipsilateral to the concavity of the FC were eligible for study inclusion and had undergone three categories of surgery: 1) FC only (FC group), 2) lower thoracic to sacrum (LT group), or 3) upper thoracic to sacrum (UT group). Primary outcomes were the rates of revision surgery and complications. Secondary outcomes were estimated blood loss, length of hospital stay, and discharge destination. Spinopelvic parameters were measured, and patients were stratified accordingly.
Of the 99 patients eligible for inclusion in the study, 27 were in the FC group, 46 in the LT group, and 26 in the UT group. There were no significant preoperative differences in age, sex, smoking status, prior operation, FC magnitude, pelvic tilt (PT), sagittal vertical axis (SVA), coronal balance, pelvic incidence–lumbar lordosis (PI-LL) mismatch, or proportion of well-aligned spines (SVA < 5 cm, PI-LL mismatch < 10°, and PT < 20°) among the three treatment groups. Mean follow-up was 30 (range 12–112) months, with a minimum 1-year follow-up. The FC group had a lower medical complication rate (22% [FC] vs 57% [LT] vs 58% [UT], p = 0.009) but a higher rate of extension surgery (26% [FC] vs 13% [LT] vs 4% [UT], p = 0.068). The respective average estimated blood loss (592 vs 1950 vs 2634 ml, p < 0.001), length of hospital stay (5.5 vs 8.3 vs 8.3 days, p < 0.001), and rate of discharge to acute rehabilitation (30% vs 46% vs 85%, p < 0.001) were all lower for FC and highest for UT.
Treatment of the FC only is associated with a lower complication rate, shorter hospital stay, and less blood loss than complete scoliosis treatment. However, there is a higher associated rate of extension of the construct to the lower or upper thoracic levels, and patients should be counseled when considering their options.
Bruce M. McCormack, Rafael C. Bundoc, Mario R. Ver, Jose Manuel F. Ignacio, Sigurd H. Berven and Edward F. Eyster
The authors present 1-year results in 60 patients with cervical radiculopathy due to spondylosis and stenosis that was treated with a bilateral percutaneous facet implant. The implant consists of a screw and washer that distracts and immobilizes the cervical facet for root decompression and fusion. Clinical and radiological results are analyzed.
Between 2009 and 2011, 60 patients were treated with the DTRAX Facet System in a multicenter prospective single-arm study. All patients had symptomatic clinical radiculopathy, and conservative management had failed. The majority of patients had multilevel radiographically confirmed disease. Only patients with single-level radiculopathy confirmed by history, physical examination, and in some cases confirmatory nerve blocks were included. Patients were assessed preoperatively with Neck Disability Index, visual analog scale, quality of life questionnaire (Short Form-12 version 2), CT scans, MRI, and dynamic radiographs. Surgery was percutaneous posterior bilateral facet implants consisting of a screw and expandable washer and iliac crest bone aspirate. Patients underwent postoperative assessments at 2 weeks, 6 weeks, 3 months, 6 months, and 1 year with validated outcome questionnaires. Alterations of segmental and overall cervical lordosis, foraminal dimensions, device retention and fusion criteria were assessed for up to 1 year with CT reconstructions and radiographs. Fusion criteria were defined as bridging trabecular bone between the facets, translational motion < 2 mm, and angular motion < 5°.
All patients were followed to 1 year postoperatively. Ages in this cohort ranged from 40 to 75 years, with a mean of 53 years. Forty-two patients were treated at C5–6, 8 at C6–7, 7 at C4–5, and 3 at C3–4. Fifty-six had bilateral implants; 4 had unilateral implants due to intraoperative facet fracture (2 patients) and inability to access the facet (2 patients). The Neck Disability Index, Short Form-12 version 2, and visual analog scale scores were significantly improved at 2 weeks and remained significantly improved up to 1 year. At the treated level, 93% had intrafacet bridging trabecular bone on CT scans, translational motion was < 2 mm in 100% and angular movement was < 5° in 83% at the 1-year follow-up. There was no significant change in overall cervical lordosis. There was a 1.6° loss of segmental lordosis at the treated level at 1 year that was significant. Foraminal width, volume, and posterior disc height was significantly increased at 6 months and returned to baseline levels at 1 year. There was no significant decrease in foraminal width and height at adjacent levels. There were no reoperations or surgery- or device-related complications, including implant failure or retained hardware.
Results indicate that the DTRAX Facet System is safe and effective for treatment of cervical radiculopathy.
Ping-Guo Duan, Praveen V. Mummaneni, Minghao Wang, Andrew K. Chan, Bo Li, Rory Mayer, Sigurd H. Berven and Dean Chou
In this study, the authors’ aim was to investigate whether obesity affects surgery rates for adjacent-segment degeneration (ASD) after transforaminal lumbar interbody fusion (TLIF) for spondylolisthesis.
Patients who underwent single-level TLIF for spondylolisthesis at the University of California, San Francisco, from 2006 to 2016 were retrospectively analyzed. Inclusion criteria were a minimum 2-year follow-up, single-level TLIF, and degenerative lumbar spondylolisthesis. Exclusion criteria were trauma, tumor, infection, multilevel fusions, non-TLIF fusions, or less than a 2-year follow-up. Patient demographic data were collected, and an analysis of spinopelvic parameters was performed. The patients were divided into two groups: mismatched, or pelvic incidence (PI) minus lumbar lordosis (LL) ≥ 10°; and balanced, or PI-LL < 10°. Within the two groups, the patients were further classified by BMI (< 30 and ≥ 30 kg/m2). Patients were then evaluated for surgery for ASD, matched by BMI and PI-LL parameters.
A total of 190 patients met inclusion criteria (72 males and 118 females, mean age 59.57 ± 12.39 years). The average follow-up was 40.21 ± 20.42 months (range 24–135 months). In total, 24 patients (12.63% of 190) underwent surgery for ASD. Within the entire cohort, 82 patients were in the mismatched group, and 108 patients were in the balanced group. Within the mismatched group, adjacent-segment surgeries occurred at the following rates: BMI < 30 kg/m2, 2.1% (1/48); and BMI ≥ 30 kg/m2, 17.6% (6/34). Significant differences were seen between patients with BMI ≥ 30 and BMI < 30 (p = 0.018). A receiver operating characteristic curve for BMI as a predictor for ASD was established, with an AUC of 0.69 (95% CI 0.49–0.90). The optimal BMI cutoff value determined by the Youden index is 29.95 (sensitivity 0.857; specificity 0.627). However, in the balanced PI-LL group (108/190 patients), there was no difference in surgery rates for ASD among the patients with different BMIs (p > 0.05).
In patients who have a PI-LL mismatch, obesity may be associated with an increased risk of surgery for ASD after TLIF, but in obese patients without PI-LL mismatch, this association was not observed.
John F. Burke, Andrew K. Chan, Rory R. Mayer, Joseph H. Garcia, Brenton Pennicooke, Michael Mann, Sigurd H. Berven, Dean Chou and Praveen V. Mummaneni
The clamshell thoracotomy is often used to access both hemithoraxes and the mediastinum simultaneously for cardiothoracic pathology, but this technique is rarely used for the excision of spinal tumors. We describe the use of a clamshell thoracotomy for en bloc excision of a 3-level upper thoracic chordoma in a 20-year-old patient. The lesion involved T2, T3, and T4, and it invaded both chest cavities and indented the mediastinum. After 2 biopsies to confirm the diagnosis, the patient underwent a posterior spinal fusion followed by bilateral clamshell thoracotomy for 3-level en bloc resection with simultaneous access to both chest cavities and the mediastinum. To demonstrate how the clamshell thoracotomy was used to facilitate the tumor resection, an operative video and illustrations are provided, which show in detail how the clamshell thoracotomy can be used to access both hemithoraxes and the mediastinum.
Kai-Ming G. Fu, Justin S. Smith, David W. Polly Jr., Christopher P. Ames, Sigurd H. Berven, Joseph H. Perra, Richard E. McCarthy, D. Raymond Knapp Jr. and Christopher I. Shaffrey
Patients with varied medical comorbidities often present with spinal pathology for which operative intervention is potentially indicated, but few studies have examined risk stratification in determining morbidity and mortality rates associated with the operative treatment of spinal disorders. This study provides an analysis of morbidity and mortality data associated with 22,857 cases reported in the multicenter, multisurgeon Scoliosis Research Society Morbidity and Mortality database stratified by American Society of Anesthesiologists (ASA) physical status classification, a commonly used system to describe preoperative physical status and to predict operative morbidity.
The Scoliosis Research Society Morbidity and Mortality database was queried for the year 2007, the year in which ASA data were collected. Inclusion criterion was a reported ASA grade. Cases were categorized by operation type and disease process. Details on the surgical approach and type of instrumentation were recorded. Major perioperative complications and deaths were evaluated. Two large subgroups—patients with adult degenerative lumbar disease and patients with major deformity—were also analyzed separately. Statistical analyses were performed with the chi-square test.
The population studied comprised 22,857 patients. Spinal disease included degenerative disease (9409 cases), scoliosis (6782 cases), spondylolisthesis (2144 cases), trauma (1314 cases), kyphosis (831 cases), and other (2377 cases). The overall complication rate was 8.4%. Complication rates for ASA Grades 1 through 5 were 5.4%, 9.0%, 14.4%, 20.3%, and 50.0%, respectively (p = 0.001). In patients undergoing surgery for degenerative lumbar diseases and major adult deformity, similarly increasing rates of morbidity were found in higher-grade patients. The mortality rate was also higher in higher-grade patients. The incidence of major complications, including wound infections, hematomas, respiratory problems, and thromboembolic events, was also greater in patients with higher ASA grades.
Patients with higher ASA grades undergoing spinal surgery had significantly higher rates of morbidity than those with lower ASA grades. Given the common application of the ASA system to surgical patients, this grade may prove helpful for surgical decision making and preoperative counseling with regard to risks of morbidity and mortality.
Takahito Fujimori, Shinichi Inoue, Hai Le, William W. Schairer, Sigurd H. Berven, Bobby K. Tay, Vedat Deviren, Shane Burch, Motoki Iwasaki and Serena S. Hu
Despite increasing numbers of patients with adult spinal deformity, it is unclear how to select the optimal upper instrumented vertebra (UIV) in long fusion surgery for these patients. The purpose of this study was to compare the use of vertebrae in the upper thoracic (UT) versus lower thoracic (LT) spine as the upper instrumented vertebra in long fusion surgery for adult spinal deformity.
Patients who underwent fusion from the sacrum to the thoracic spine for adult spinal deformity with sagittal imbalance at a single medical center were studied. The patients with a sagittal vertical axis (SVA) ≥ 40 mm who had radiographs and completed the 12-item Short-Form Health Survey (SF-12) preoperatively and at final follow-up (≥ 2 years postoperatively) were included.
Eighty patients (mean age of 61.1 ± 10.9 years; 69 women and 11 men) met the inclusion criteria. There were 31 patients in the UT group and 49 patients in the LT group. The mean follow-up period was 3.6 ± 1.6 years. The physical component summary (PCS) score of the SF-12 significantly improved from the preoperative assessment to final follow-up in each group (UT, 34 to 41; LT, 29 to 37; p = 0.001). This improvement reached the minimum clinically important difference in both groups. There was no significant difference in PCS score improvement between the 2 groups (p = 0.8). The UT group had significantly greater preoperative lumbar lordosis (28° vs 18°, p = 0.03) and greater thoracic kyphosis (36° vs 18°, p = 0.001). After surgery, there was no significant difference in lumbar lordosis or thoracic kyphosis. The UT group had significantly greater postoperative cervicothoracic kyphosis (20° vs 11°, p = 0.009). The UT group tended to maintain a smaller positive SVA (51 vs 73 mm, p = 0.08) and smaller T-1 spinopelvic inclination (−2.6° vs 0.6°, p = 0.06). The LT group tended to have more proximal junctional kyphosis (PJK), although the difference did not reach statistical significance. Radiographic PJK was 32% in the UT group and 41% in the LT group (p = 0.4). Surgical PJK was 6.4% in the UT group and 10% in the LT group (p = 0.6).
Both the UT and LT groups demonstrated significant improvement in clinical and radiographic outcomes. A significant difference was not observed in improvement of clinical outcomes between the 2 groups.
Ping-Guo Duan, Praveen V. Mummaneni, Joshua Rivera, Jeremy M. V. Guinn, Minghao Wang, Zhuo Xi, Bo Li, Hao-Hua Wu, Christopher P. Ames, Shane Burch, Sigurd H. Berven and Dean Chou
Patients undergoing long-segment fusions from the lower thoracic (LT) spine to the sacrum for adult spinal deformity (ASD) correction are at risk for proximal junctional kyphosis (PJK). One mechanism of PJK is fracture of the upper instrumented vertebra (UIV) or higher (UIV+1), which may be related to bone mineral density (BMD). Because Hounsfield units (HUs) on CT correlate with BMD, the authors evaluated whether HU values were correlated with PJK after long fusions for ASD.
The authors performed a retrospective study of patients older than 50 years who had undergone ASD correction from the LT spine to the sacrum in the period from October 2007 to January 2018 and had a minimum 2-year follow-up. Demographic and spinopelvic parameters were measured. HU values were measured on preoperative CT at the UIV, UIV+1, and UIV+2 (2 levels above the UIV) levels and were assessed for correlations with PJK.
The records of 127 patients were reviewed. Fifty-four patients (19 males and 35 females) with a mean age of 64.91 years and mean follow-up of 3.19 years met the study inclusion criteria; there were 29 patients with PJK and 25 patients without. There was no statistically significant difference in demographics or follow-up between these two groups. Neither was there a difference between the groups with regard to postoperative pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), PI minus LL (PI-LL), thoracic kyphosis (TK), or sagittal vertical axis (SVA; all p > 0.05). Postoperative pelvic tilt (p = 0.003) and T1 pelvic angle (p = 0.014) were significantly higher in patients with PJK than in those without. Preoperative HUs at UIV, UIV+1, and UIV+2 were 120.41, 124.52, and 129.28 in the patients with PJK, respectively, and 152.80, 155.96, and 160.00 in the patients without PJK, respectively (p = 0.011, 0.02, and 0.018). Three receiver operating characteristic (ROC) curves for preoperative HU values at the UIV, UIV+1, and UIV+2 as a predictor for PJK were established, with areas under the ROC curve of 0.710 (95% CI 0.574–0.847), 0.679 (95% CI 0.536–0.821), and 0.681 (95% CI 0.539–0.824), respectively. The optimal HU value by Youden index was 104 HU at the UIV (sensitivity 0.840, specificity 0.517), 113 HU at the UIV+1 (sensitivity 0.720, specificity 0.517), and 110 HU at the UIV+2 (sensitivity 0.880, specificity 0.448).
In patients undergoing long-segment fusions from the LT spine to the sacrum for ASD, PJK was associated with lower HU values on CT at the UIV, UIV+1, and UIV+2. The measurement of HU values on preoperative CTs may be a useful adjunct for ASD surgery planning.