Predictors of Length of Hospital Stay After Reduction of Internal Hernia in Patients With a History of Roux-en-Y Gastric Bypass

BACKGROUND

Postoperative internal hernias after Roux-en-Y gastric bypass (RYGB) have an incidence of 2%-9% and are a surgical emergency. Evidence on factors associated with length of stay (LOS) after emergent internal hernia reduction in RYGB patients is limited.

METHODS

This is a retrospective review of patients who underwent internal hernia reduction after RYGB at our tertiary care center over a 5 year period from 2015 to 2020. Demographics, comorbidities, and intra- and postoperative hospital course were collected. Univariate and multivariate linear regressions were used to investigate factors associated with LOS.

RESULTS

We identified 38 patients with internal hernia after RYGB. These patients with mean age 44.1 years were majority female (71.1%) and white race (60.5%). Of the 24 patients where the RYGB was done at our institution, the mean RYGB to IH interval was 43 months. Petersen's defect (57.8%) followed by jejuno-jejunal mesenteric defect (31.6%) were the most common locations for IH. Both Petersen's and jejuno-jejunal mesenteric hernias were found in 4 cases (10.5%). Revision of bypass and small bowel resection were required in 13.2% and 5.3% of cases, respectively. The median (interquartile range) length of stay (LOS) was 2 days. On the multivariate analysis, male sex (P = .019), conversion to exploratory laparotomy (P = .005), and resection of small bowel (P < .001) were independent risk factors for increased LOS.

CONCLUSION

The most common location of IH after RYGB is Petersen's defect, followed by jejuno-jejunal mesenteric defect. LOS was significantly associated with male sex, exploratory laparotomy, and resection of small bowel.

Trends in gastric surgery operative experience among general surgery residents in the United States: A nationwide retrospective analysis

BACKGROUND

Gastric surgery is a crucial component of general surgery training. However, there is a paucity of high-quality data on operative volume and the diversity of surgical procedures that general surgery residents are exposed to.

METHODS

We conducted a retrospective analysis of operative case logs of all general surgery residents graduating from the American College of Graduate Medical Education-accredited program from 2009 to 2022. Data on the mean number of gastric procedures, including the mean in each subcategory, were retrieved. A Mann-Kendall trend test was used to investigate trends in operative volume.

RESULTS

Between 2009 and 2022, the mean overall logged gastric procedures rose significantly (τ = 0.722, P < .001) from 36.2 in 2009 to 49.2 in 2022 (35.9% increase). The most substantial growth was seen in laparoscopic gastric reduction for morbid obesity (mean 1.9 in 2017 to 19 in 2022; τ = 0.670, P = .009). A statistically significant increase was also seen in laparoscopic partial gastric resections, repair of gastric perforation, and "other major stomach procedures" (P < .05 for all comparisons). Open gastrostomy, open partial gastric resections, and open vagotomy all significantly decreased (P < .05 for all comparisons). There was no significant change in the volume of laparoscopic gastrectomy, total gastric resections, and non-laparoscopic gastric reductions for morbid obesity (P > .05 for all comparisons).

CONCLUSION

There has been a substantial increase in the volume of gastric surgery during residency over the past 14 years, driven mainly by an increase in laparoscopic gastric reduction. However, there may still be a need for further gastric surgical training to ensure well-rounded general surgeons.

Superinfections of the Spine: A Single-Institution Experience

Background/Objectives: A superinfection occurs when a new, secondary organism colonizes an existing infection. Spine infections are associated with high patient morbidity and sometimes require multiple irrigations and debridements (I&Ds). When multiple I&Ds are required, the risk of complications increases. The purpose of this study was to report our experience with spine superinfections and determine which patients are typically affected. Methods: A retrospective case series of spine superinfections and a retrospective case-control analysis were conducted. Data were collected manually from electronic medical records. Spine I&Ds were identified. Groups were created for patients who had multiple I&Ds for (1) a recurrence of the same causative organism or (2) a superinfection with a novel organism. Preoperative demographic, clinical, and microbiologic data were compared between these two outcomes. A case series of superinfections with descriptive data was constructed. Lastly, two illustrative cases were provided in a narrative format. Results: A total of 92 patients were included in this analysis. Superinfections occurred after 6 out of the 92 (7%) initial I&Ds and were responsible for 6 out of the 24 (25%) repeat I&Ds. The preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) of the patients with a superinfection were significantly lower than those in the control group (p = 0.022 and p = 0.032). Otherwise, the observed differences in the preoperative variables were not statistically different. In the six cases of superinfection, the presence of high-risk comorbidities, a history of substance abuse, or a lack of social support were commonly observed. The superinfecting organisms included Candida, Pseudomonas, Serratia, Klebsiella, Enterobacter, and Staphylococcus species. Conclusions: Superinfections are a devastating complication requiring reoperation after initial spine I&D. Awareness of the possibility of superinfection and common patient archetypes can be helpful for clinicians and care teams. Future work is needed to examine how to identify, help predict, and prevent spine superinfections.

Operative Experience of Esophageal Surgery among General Surgery Residents in the United States: An Analysis of ACGME Operative Case Logs

INTRODUCTION

Esophageal surgery is an essential component of general surgery training and encompasses several types of cases that are logged by general surgery residents. There is a scarcity of data on the quality and volume of esophageal surgery experience during surgical residency in the United States. We analyzed trends for 9 different esophageal procedure categories logged by residents in the United States, with the aim to identify areas for improvement in training.

METHODS

We conducted a retrospective analysis of operative case logs of all general surgery residents graduating from programs accredited by the ACGME over a fourteen-year period from 2009 to 2023. Data on mean esophageal cases reported by graduates, including mean in each procedure subcategory were retrieved. Cases were categorized as either surgeon chief or surgeon junior for each procedure category. Mann-Kendall trend test was used to obtain tau statistics and p-value for trends in mean operative surgical volume for the total number of cases in each operative category over the study period. Trends in surgeon chief and surgeon junior cases were also investigated for each operative category.

RESULTS

The mean number of all esophageal procedures performed per resident during their training increased significantly from 10.5 in 2009 to 16 in 2022 (τ = 0.833, p < 0.001). This trend observed among all esophageal procedures during this 14-year study can be largely attributed to the steady increase in the number and proportion of laparoscopic esophageal antireflux procedures performed (τ = 0.950, p < 0.001). Additionally, esophagectomy procedures had a statistically significant, but modest, increase during the study period (τ = 0.505, p = 0.023), from a mean of 1 case during training in 2009 to a peak of 1.3 in 2020. Although the general trend of esophagus procedures increased during the study period, most categories (7 out of 9) either decreased or did not significantly change. Esophagogastrectomy volume decreased significantly by 30%, from 1 per resident during their training in 2009 to 0.7 in 2022 (τ = -0.510, p = 0.018), esophageal diverticulectomy procedures decreased by 50% from 0.2 to 0.1 (τ = -0.609, p = 0.009), and operations for esophageal stenosis decreased by 75% from 0.4 to 0.1 (τ = -0.734, p = 0.001). Mean number of esophageal bypasses (τ = -0.128, p = 0.584), repair of perforated esophageal disease (τ = -0.333, p = 0.156), and other major esophagus procedures (τ = 0.416, p = 0.063) did not significantly change.

CONCLUSION

The operative volume of esophageal surgery that general surgery residents in the United States are exposed to has significantly risen over the past 14 years, largely driven by the increase in laparoscopic antireflux procedures. However, given the recent advances and the resultant heterogeneity in both esophageal surgery, the increase in resident operative volume is still inadequate to ensure the training of safe and adept esophageal surgeons, necessitating postresidency specialized training for trainees interested in esophageal surgery.

Colon and Rectal Surgery Fellowship Applicant and Matching Trends in the United States: An Analysis of National Resident Matching Program Data

BACKGROUND

Colon and Rectal Surgery fellowships are training programs that aim to train surgeons in the management of small bowel, colon, rectal, and anal pathologies.

OBJECTIVE

We investigated trends in Colon and Rectal Surgery fellowship match to help applicants anticipate future fellowship application cycles.

DESIGN

This was a retrospective cohort study of applicants in the Colon and Rectal Surgery match from 2009 to 2023. Proportion of positions filled, match rates, and rank-order lists were collected. The impact of US-MD, non-US-MD, and DO status on match rate was assessed. We used the Mann Kendall trend test to obtain tau statistic and P-value for temporal trends over time, while associations between categorical variables were investigated by a chi-square test.

RESULTS

Fellowship programs increased from 43 to 67, positions increased from 78 to 110, and number of applicants rose from 113 to 135. Nearly all positions were filled from 2009 to 2023 (range: 96.3%-100%). The overall match rate fluctuated between 67.3% and 80.7%. The match rate over the past 5 years was 72.0%. The match rate for US-MDs was 80.0%, while non-US-MDs had a 56.2% match rate. The percentage matching at each rank were first choice 28.0%, second choice 10.4%, third choice 6.9%, and fourth choice or lower 23.5%.

CONCLUSION

Despite an increase in Colon and Rectal Surgery fellowship positions, the overall match rate has not changed significantly over the years, mainly as a result of increased applicants.

Trends in Surgical Critical Care Fellowship Match: An Analysis of National Resident Matching Program Data

INTRODUCTION

Surgical Critical Care (SCC) fellowship applications are made through March-July the year prior to the fellowship, while the match process takes place through the National Resident Matching Program (NRMP). There is paucity of high quality data on matching trends in SCC fellowship in the United States.

METHODS

We conducted a retrospective cohort study of all applicants in the SCC match over a period of fifteen years (2009-2023). Publicly published data about the SCC fellowship match were retrieved from the NRMP online portal. Mann Kendall trend test was used to obtain a Tau statistic and p-values for temporal trends over time. Chi-square test was used to investigate association between categorical variables.

RESULTS

From 2009 to 2023, the number of SCC fellowship positions increased from 143 to 340 (138% increase) while the number of applicants rose from 95 to 289 (204% increase). The overall match rate for applicants significantly rose from 89.5% to 93.4% (7.7% increase; t = 0.600, p = 0.002). The percentage of positions filled also increased from 59.4% in 2009 to 79.4% in 2023. The match rate over the past five years (2019-2023) was 90.8%. US-MD applicants had a significantly higher 94.8% match rate throughout the study period than non-US MD applicants (94.8% vs. 87.3%, p<0.001). While the match rate for US-MD applicants has stayed consistent from 2009 to 2023 (τ = 0.371, p = 0.054), the match rate for non-US-MD applicants increased from 77.3% in 2009 to 86.9% in 2023 (τ = 0.771, p<0.001).

CONCLUSION

SCC fellowship continues to grow with more positions and applicants. Match rates into SCC fellowships have increased over the past fifteen years, primarily helping non-US MDs match successfully.

The Utility of the Validated Intraoperative Bleeding Scale in Thoracolumbar Spine Surgery: A Single-Center Prospective Study

STUDY DESIGN

Prospective, single-center study.

OBJECTIVE

To evaluate the clinical relevance of the validated intraoperative bleeding severity scale (VIBe) in thoracolumbar spine surgery.

METHODS

Adult patients aged 18 through 88 undergoing elective decompression, instrumentation, and fusion of the thoracolumbar spine were prospectively enrolled after informed consent was provided and written consent was obtained. Validated intraoperative bleeding severity scores were recorded intraoperatively. Univariate analysis consisted of Student T-tests, Pearson's χ2 Tests, Fisher's Exact Tests, linear regression, and binary logistic regression. Multivariable regression was conducted to adjust for baseline characteristics and potential confounding variables.

RESULTS

A total of N = 121 patients were enrolled and included in the analysis. After adjusting for confounders, VIBe scores were correlated with an increased likelihood of intraoperative blood transfusion (β = 2.46, P = .012), postoperative blood transfusion (β = 2.36, P = .015), any transfusion (β = 2.49, P < .001), total transfusion volume (β = 180.8, P = .020), and estimated blood loss (EBL) (β = 409, P < .001). Validated intraoperative bleeding severity scores had no significant association with length of hospital stay, 30-day readmission, 30-day reoperation, 30-day emergency department visit, change in pre- to post-op hemoglobin and hematocrit, total drain output, or length of surgery.

CONCLUSION

The VIBe scale is associated with perioperative transfusion rates and EBL in patients undergoing thoracolumbar spine surgery. Overall, the VIBe scale has clinically relevant meaning in spine surgery, and shows potential utility in clinical research.

LEVEL OF EVIDENCE

Level II.

Marijuana and Vascular Disease: A Review

Marijuana use is common and increasing due to decriminalization, legalization, and expansion of medical use. As a result, the proportion of vascular patients with marijuana is also expected to increase, raising questions if cannabis use affects the incidence and outcomes of vascular disease. Active ingredients of cannabis have been shown to interact with receptors found on vascular endothelium, promoting oxidative stress and endothelial dysfunction. However, current clinical studies have yet to demonstrate a relationship between marijuana use and atherosclerosis. Nonetheless, cannabis arteritis is a rare condition where cannabis is hypothesized to induce vascular inflammation. Future research with high-quality studies is needed to clarify the impact of marijuana use on vascular diseases.

Telemedicine Improves Access to Care for Spine Patients With Low Socioeconomic Status

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The objective of this study is to compare the likelihood of missing a scheduled telemedicine and in-person appointments for spine patients. The secondary objective is to assess the impact of socioeconomic status on missed telemedicine and in-person appointments.

METHODS

Patients with scheduled outpatient appointments with orthopedic spine faculty between 2019 and 2021 were divided by appointment type: telemedicine (N = 4,387) and in-person (N = 3810). Socioeconomic status was assessed using Area Deprivation Index (ADI) stratified based on percentile: low (<25), medium (25-75), and high (>75) levels of socioeconomic disadvantage. The primary outcome measure was missed clinic appointments, which was defined as having at least one appointment that was cancelled or labeled "no show."

RESULTS

Patients with in-person appointments missed appointments more often than patients with telemedicine visits (51.3% vs 24.7%, P < .001). Patients with high ADI missed their in-person appointments more often than patients with medium and low ADI (59.5% vs 52.2% and 47.5%, P < .001). There was no difference in missed telemedicine visits between patients with high, medium, and low ADI (27.6% vs 24.8% vs 23.8%, P = .294). Patients that missed an appointment were 41.9% more likely to be high ADI (OR 1.42, 95% CI 1.20-1.68, P < .001) and 13.4% more likely to be medium ADI (OR 1.13, 95% CI 1.03-1.26, P = .015) compared with low ADI patients.

CONCLUSIONS

Telemedicine may serve a role in reducing disparity in appointment attendance. While further studies are needed to validate these findings, spine surgeons should consider offering telemedicine as an option to patients.

Temporal trends in mortality location in patients with anal cancer in the USA: an analysis of the National Center for Health Statistics mortality data

OBJECTIVES

Investigate trends in where patients died of anal cancer in the USA.

METHODS

Retrospective cohort study using the US National Center for Health Statistics Wide-Ranging ONline Data for Epidemiologic Research platform from 2003 to 2020; all patients with death certificates listing anal cancer as the underlying cause of death in the USA. Main outcome measure of location of patient death: inpatient facility, home, hospice, nursing home/long-term care facility and other.

RESULTS

There were a total of 16 296 deaths with anal cancer as the underlying diagnosis during the study period. The crude rate increased from 0.191 per 100 000 deaths in 2003 to 0.453 per 100 000 deaths in 2020. Over the study period, 22.4% of patient deaths occurred in inpatient facilities, 44.9% at home, 12.2% at hospice facilities and 13.1% at nursing homes/long-term care facilities. The percentage of deaths occurring in hospice facilities increased from 1.0% to 13.3% during the study period. Deaths at home also increased from 42.7% in 2003 to 55.8% in 2020. Meanwhile, inpatient deaths decreased from 33.5% in 2003 to 14.4% in 2020.

CONCLUSIONS

There has been a significant increase in the proportion of patients with anal cancer dying at home or hospice from 2003 to 2020.

Retrospective Analysis of Causes and Risk Factors of 30-Day Readmission After Spine Surgery for Thoracolumbar Trauma

STUDY DESIGN

Retrospective Case Series.

OBJECTIVE

This study aims to evaluate readmission rates, risk factors, and reason for unplanned 30-day readmissions after thoracolumbar spine trauma surgery.

METHODS

A retrospective chart review was conducted for patients undergoing operative treatment for thoracic or lumbar trauma with open or minimally invasive surgical approach at a Level 1 urban trauma center. Patients were divided into two groups based on 30-day readmission status. Reason for readmission, reoperation rates, injury type, trauma severity, and incidence of polytrauma were compared between the two groups.

RESULTS

A total of 312 patients, 69.9% male with an average age of 47 ± 19 years were included. The readmitted group included 16 patients (5.1%) of which 9 (56%) were readmitted for medical complications and 7 for surgical complications. Wound complications (31.3% of readmissions) were the most common cause of readmission, followed by non-wound related sepsis (18.9% of readmissions). A total of 6 patients (37.5%) required reoperation; 2 instrumentation failures underwent revision surgery, and 4 wound complications underwent irrigation and debridement. Patients with higher Injury Severity Scale (ISS) were more likely to be readmitted (27.8% vs 22.1%, P = .045). Concomitant lower limb surgery increased odds of readmission (OR, 4.40; 95% CI, 1.10-17.83; P = .037).

CONCLUSION

Spine trauma 30-day readmission rate was 5.1%, comparable to those reported in the elective spine surgery literature. Readmitted patients were more likely to sustain concomitant operative lower limb trauma. Wound complications were the most common cause of readmission, and almost half of the patients were readmitted due to surgery-related complications.

Open vs Percutaneous Pedicle Instrumentation for Kyphosis Correction in Traumatic Thoracic and Thoracolumbar Spine Injuries

OBJECTIVES

Percutaneous pedicle instrumentation (PPI) has been used for the treatment of thoracic and thoracolumbar (TL) trauma. However, the ability of PPI to correct significant post-traumatic kyphosis requires further investigation. The objective of this study is to compare the amount of kyphosis correction achieved by PPI vs the traditional open posterior approach in patients presenting with significant kyphotic deformity following traumatic thoracic and TL spine injuries.

METHODS

Following Institutional Review Board approval, patients who underwent surgery for thoracic (T1-T9) or TL (T10-L2) fractures with at least 15° of focal kyphosis in a 5-year period were included in this study. Patients were separated into 2 cohorts based on surgical technique: traditional open posterior approach and minimally invasive PPI. Kyphosis correction was measured using Cobb angle 1 vertebrae above and 1 below the level of injury on sagittal preoperative computed tomography image, immediate and follow-up postoperative upright lateral radiographs. Initial degree of correction and loss of correction at the final follow-up were compared.

RESULTS

Of 91 patients included, 65 (71%) underwent open surgery and 26 (29%) underwent PPI. Open patients had 11° (95% CI, 9°-13°) of immediate correction compared with 11° (95% CI, 6°-15°) for PPI (P = 0.81). Follow-up data were available for 70 patients with a median of 105.5 days. Both groups had 1° (95% CI, 0°-2°) of loss of correction at follow-up (P = 0.82). Regardless of surgical technique, obesity (>30 kg/m²) and AO type-A compression fractures had significantly less correction. For each unit of body mass index, there was a 0.75° decrease in correction achieved (P < 0.0001). Other factors did not influence the degree of correction.

CONCLUSIONS

PPI techniques provide equivalent postoperative angular correction and maintenance of correction compared with open surgery in thoracic and TL trauma patients.

CLINICAL RELEVANCE

This study provides evidence for spine surgeons to utilize either technique for treating significant traumatic kyphotic deformity.

LEVEL OF EVIDENCE

Therapeutic 3.

Predicting Length of Stay After Thoracolumbar Trauma: A Single-Center, Retrospective Analysis

BACKGROUND

Length of stay (LOS) is a meaningful outcome measure for more efficient and effective quality of care. However, algorithms to predict LOS have yet to be created for patients who undergo surgical management for traumatic spinal fractures.

OBJECTIVES

The objectives of this study were to (1) identify preoperative, perioperative, and postoperative factors associated with increased LOS and (2) create predictive formulas to estimate LOS in thoracolumbar trauma patients who undergo surgical correction.

METHODS

This is a retrospective case series of 196 patients operated for thoracolumbar spine trauma from January 2012 to December 2017 at a level 1 trauma and academic institution. Bivariate analysis between LOS and various preoperative, perioperative, and postoperative factors was conducted to identify significant associations. Multivariate analysis was conducted to create models capable of predicting LOS.

RESULTS

LOS was significantly associated with various preoperative (eg, Charlson Comorbidity Index, Glasgow Coma Scale [GCS], injury severity score), operative (eg, length of surgery, number of instrumented segments, surgical technique), and postoperative variables (eg, complications, discharge location). Multivariate analysis of preoperative variables identified 5 significant independent predictors that could predict LOS with strong correlation with observed LOS (ρ = 0.63). With all variables considered, multivariate analysis identified 8 variables (GCS, American Society of Anesthesiologists score, neurological status, polytrauma, packed red blood cell transfusion, number of unique postoperative complications, skin complications, and discharge facility) that could predict LOS with strong correlation (ρ = 0.80).

CONCLUSIONS

Various preoperative, perioperative, and postoperative factors are significantly associated with LOS in traumatic thoracolumbar spine patients. We developed models with good predictive capacity for LOS. If validated, these models should help in risk stratifying patients for increased LOS and consequently improve perioperative patient counseling.

CLINICAL RELEVANCE

This article contributes to identifying and predicting patients who are high risk for extended LOS after traumatic thoracolumbar injuries.

LEVEL OF EVIDENCE: 4

Postoperative outcomes of minimally invasive pedicle screw fixation for treatment of unstable pathologic neoplastic fractures

STUDY DESIGN

Retrospective Case Series.

OBJECTIVES

Minimally invasive techniques have emerged as a useful tool in the treatment of neoplastic spine pathology due to decrease in surgical morbidity and earlier adjuvant treatment. The objective of this study was to analyze outcomes and complications in a cohort of unstable, symptomatic pathologic fractures treated with percutaneous pedicle screw fixation (PPSF).

METHODS

A retrospective review was performed on consecutive patients with spinal stabilization for unstable pathologic neoplastic fractures between 2007 and 2017. Patients who underwent PPSF through a minimally invasive approach were included. Surgical indications included intractable pain, mechanical instability, and neurologic compromise with radiologic visualization of the lesion.

RESULTS

20 patients with mean Tomita Score of 6.3 ± 2.1 points [95% CI, 5.3-7.2] were treated with constructs that spanned a mean of 4.7 ± 1.4 [95% CI, 4.0-5.3] instrumented levels. 10 (50%) patients were augmented with vertebroplasty. Majority of patients (65%) had no complications during their hospital stay and were discharged home (60%). Four patients received reoperation: two extracavitary corpectomies, one pathologic fracture at a different level, and one adjacent segment disease.

CONCLUSION

Minimally invasive PPSF is a safe and effective option when treating unstable neoplastic fractures and may be a viable alternative to the traditional open approach in select cases.

LEVEL OF EVIDENCE

4.

Outpatient versus inpatient total shoulder arthroplasty: A cost and outcome comparison in a comorbidity matched analysis

Background

Previous studies comparing total and reverse shoulder arthroplasty (TSA/RSA) are subject to surgeon selection bias. This study objective is to compare the outcomes and cost of outpatient TSA/RSA to inpatient TSA/RSA.

Methods

108,889 elective inpatient and outpatient TSA/RSA from Medicare claims data (2016-2018). 90-day readmission and total 90-day costs were compared following propensity score matching.

Results

Younger and healthier patients are receiving outpatient TSA/RSA. Outpatient TSA/RSA was associated with fewer 90-day readmissions (OR 0.48 CI 0.38-0.59, p < 0.001) and lower 90-day costs (-20.1% CI -19.1%; -21.1%, p < 0.001).

Conclusions

Outpatient TSA/RSA surgery offers lower complication rates and total costs.

Level of evidence

III.

Automated Measurement of Lumbar Lordosis on Radiographs Using Machine Learning and Computer Vision

STUDY DESIGN

Cross sectional database study.

OBJECTIVE

To develop a fully automated artificial intelligence and computer vision pipeline for assisted evaluation of lumbar lordosis.

METHODS

Lateral lumbar radiographs were used to develop a segmentation neural network (n = 629). After synthetic augmentation, 70% of these radiographs were used for network training, while the remaining 30% were used for hyperparameter optimization. A computer vision algorithm was deployed on the segmented radiographs to calculate lumbar lordosis angles. A test set of radiographs was used to evaluate the validity of the entire pipeline (n = 151).

RESULTS

The U-Net segmentation achieved a test dataset dice score of 0.821, an area under the receiver operating curve of 0.914, and an accuracy of 0.862. The computer vision algorithm identified the L1 and S1 vertebrae on 84.1% of the test set with an average speed of 0.14 seconds/radiograph. From the 151 test set radiographs, 50 were randomly chosen for surgeon measurement. When compared with those measurements, our algorithm achieved a mean absolute error of 8.055° and a median absolute error of 6.965° (not statistically significant, P > .05).

CONCLUSION

This study is the first to use artificial intelligence and computer vision in a combined pipeline to rapidly measure a sagittal spinopelvic parameter without prior manual surgeon input. The pipeline measures angles with no statistically significant differences from manual measurements by surgeons. This pipeline offers clinical utility in an assistive capacity, and future work should focus on improving segmentation network performance.

Can C7 Slope Be Used as a Substitute for T1 Slope? A Radiographic Analysis

STUDY DESIGN

Retrospective radiographic study.

OBJECTIVES

T1 slope is an important parameter of sagittal spinal balance. However, the T1 superior endplate can be difficult to visualize on radiographs due to overlying anatomical structures. C7 slope has been proposed as a potential substitute for T1 slope when the T1 superior endplate is not well visualized. The objective of this study was 2-fold: (1) to assess the correlation between C7 and T1 slopes on upright cervical spine radiographs and (2) to evaluate the interrater reliability of C7 slope.

METHODS

Cervical spine radiographs taken between December 2017 and June 2018 at a single institution were reviewed. Two observers measured upper C7 slope, lower C7 slope, and T1 slope. The correlations between upper and lower C7 slope and T1 slope were evaluated, and linear regression analyses were performed. Interrater reliability of C7 slope was also assessed.

RESULTS

In this cohort of 152 patients, there was a strong correlation between upper C7 slope and T1 slope (r = 0.91, P < .001), as well as between lower C7 slope and T1 slope (r = 0.90, P < .001). T1 slope could be estimated from the linear regression equation, T1 slope = 0.87 × C7 slope + 7, with an overall model fit of R ² = 0.8. There was strong interrater reliability for upper (intraclass correlation coefficient [ICC] = 0.95, P < .001) and lower C7 slope (ICC = 0.96, P < .001).

CONCLUSIONS

Both the upper and lower C7 slope are strongly correlated with T1 slope and can be used as a substitute to estimate T1 slope when the superior endplate of T1 is not well visualized.

The Effects of Liver Disease on Surgical Outcomes Following Adult Spinal Deformity Surgery

BACKGROUND

As the prevalence of chronic liver disease continues to rise in the United States, understanding the effects of liver dysfunction on surgical outcomes has become increasingly important. The objective of this study was to assess the effects of chronic liver disease on 30-day complications following adult spinal deformity (ASD) surgery.

METHODS

We performed a retrospective cohort study of 2337 patients in the 2008-2015 American College of Surgeons National Surgical Quality Improvement Program database who underwent corrective ASD surgery. Patients with liver disease were identified based on a Model for End-Stage Liver Disease-Na score ≥10. A univariate analysis was performed to compare 30-day postoperative complications between patients with and without liver disease. A multivariate regression analysis adjusting for differences in baseline patient characteristics was performed to identify complications that were associated with liver disease.

RESULTS

Patients with liver disease had a significantly greater incidence of postoperative pulmonary complications (6.3% vs. 2.9%; P < 0.001), blood transfusion (34.6% vs. 24.0%; P < 0.001), sepsis (2.2% vs. 0.9%; P = 0.011), prolonged hospitalization (19.0% vs. 8.0%; P < 0.001), as well as any 30-day complication (45.4% vs. 29.4%; P < 0.001). The multivariate regression analysis identified liver disease as a risk factor for prolonged hospitalization (odds ratio [OR] 2.16; 95% confidence interval [CI] 1.64-2.84; P < 0.001), pulmonary complications (OR 1.78; 95% CI 1.16-2.74; P = 0.009), blood transfusion (OR 1.67; 95% CI 1.36-2.05; P < 0.001), and any 30-day complication (OR 1.43; 95% CI 1.15-1.77; P = 0.001).

CONCLUSIONS

The multisystem pathophysiology of liver dysfunction predisposes patients to postoperative complications following ASD surgery. A multidisciplinary approach in surgical planning and preoperative optimization is needed to minimize liver disease-related complications and improve patient outcomes.

Risk Factors Associated with 30-Day Mortality After Open Reduction and Internal Fixation of Vertebral Fractures

OBJECTIVE

Few studies have examined the outcomes of open reduction and internal fixation of vertebral fractures. The purpose of this study was to determine patient-related and surgery-related risk factors associated with 30-day postoperative mortality after open reduction and internal fixation (ORIF) of cervical, thoracic, and lumbar vertebral fractures.

METHODS

This was a retrospective cohort study of data from the 2010-2014 ACS-NSQIP database. Adult patients who underwent ORIF of vertebral fractures in the cervical, thoracic, or lumbar spine were included. Patients were divided into 2 groups on the basis of the occurrence of 30-day postoperative mortality. A univariate analysis was performed to compare baseline patient characteristics, comorbidities, operative variables, and 30-day postoperative complications between the mortality and nonmortality groups. A subsequent multivariate regression analysis adjusting for patient and operative factors was then performed to identify independent risk factors for 30-day mortality.

RESULTS

A total of 900 patients who underwent vertebral ORIF were included. The overall 30-day postoperative mortality rate was 1.56%. The mortality group had a higher incidence of pneumonia, pulmonary complications, cardiac complications, blood transfusion, sepsis, and prolonged hospitalization. Multivariate regression analysis identified pulmonary comorbidity and diabetes as independent predictors of 30-day mortality following ORIF of vertebral fractures.

CONCLUSIONS

Pulmonary comorbidity and diabetes were found to be independent risk factors for 30-day mortality after ORIF of vertebral fractures. Recognizing these risk factors is important in preoperative risk stratification, perioperative care, and patient counseling.

Tetrahedron-based orthogonal simultaneous scan for cone-beam computed tomography

In this article, a cone-beam computed tomography scanning mode is designed using four x-ray sources and a spherical sample. The x-ray sources are mounted at the vertices of a regular tetrahedron. On the circumsphere of the tetrahedron, four detection panels are mounted opposite of each vertex. To avoid x-ray interference, the largest half angle of each x-ray cone beam is 27°22', while the radius of the largest ball fully covered by all the cone beams is 0.460, when the radius of the circumsphere is 1. A proposed scanning scheme consists of two rotations about orthogonal axes, such that, each quarter turn provides sufficient data for theoretically exact and stable reconstruction. This design can be used in biomedical or industrial settings, such as when a sequence of reconstructions of an object is desired.