Classification of perioperative complications in spine surgery

Nadir Hemoglobin Concentration After Spinal Tumor Surgery: Association With Risk of Composite Adverse Events

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

To explore the association of early postoperative nadir hemoglobin with risk of a composite outcome of anemia-related and other adverse events.

METHODS

We retrospectively analyzed data from spinal tumor patients who received intraoperative blood transfusion between September 1, 2013 and December 31, 2020. Uni- and multivariate logistic regression was used to explore relationships of clinicodemographic and surgical factors with risk of composite in-hospital adverse events, including death. Subgroup analysis explored the relationship between early postoperative nadir hemoglobin and composite adverse events.

RESULTS

Among the 345 patients, 331 (95.9%) experienced early postoperative anemia and 69 (20%) experienced postoperative composite adverse events. Multivariate logistic regression analysis showed that postoperative nadir Hb (OR = .818, 95% CI: .672-.995, P = .044), ASA ≥3 (OR = 2.007, 95% CI: 1.086-3.707, P = .026), intraoperative RBC infusion volume (OR = 1.133, 95% CI: 1.009-1.272, P = .035), abnormal hypertension (OR = 2.199, 95% CI: 1.085-4.457, P = .029) were correlated with composite adverse events. The lumbar spinal tumor was associated with composite adverse events with a decreased odds compared to thoracic spinal tumors (OR = .444, 95% CI: .226-.876, P = .019). Compared to patients with postoperative nadir hemoglobin ≥11.0 g/dL, those with nadir <9.0 g/dL were at significantly higher risk of postoperative composite adverse events (OR = 2.709, 95% CI: 1.087-6.754, P = .032).

CONCLUSION

Nadir hemoglobin <9.0 g/dL after spinal tumor surgery is associated with greater risk of postoperative composite adverse events in patients who receive intraoperative blood transfusion.

Systematic Review of Surgical Success, Complications, Revision Rates, Radiation Dosage, and Operative Time of 3D-Navigated versus Non-Navigated Spinal Procedures

OBJECTIVE

Three-dimensional (3D) navigation offers real-time guidance in surgery. However, there is limited and inconsistent data regarding the usability, safety, and efficacy. To address gaps in knowledge about 3D navigation in spinal surgery, we conducted a comprehensive review of success rates, complications, revisions, radiation exposure, and operative time associated with Federal and Drug Administration-approved 3D surgical navigation tools.

METHODS

This study adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and used a protocol registered on International Prospective Registration of Systematic Reviews (CRD42023404554). Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched using relevant keywords for 3D surgical navigation and spinal procedures from 1946 to March 02, 2023. Two independent reviewers assessed the studies using inclusion/exclusion criteria and risk of bias tools. Statistical analyses included one-way analysis of variance, weighted-mean difference, and unpaired t-tests with Welch's correction for associations and comparisons between groups, respectively.

RESULTS

Of the total 11,324 studies identified and 7198 screened, 62 studies totaling 3170 adult patients were included in this comprehensive review. Complication and surgical success rates have remained constant since 2004, with overall rates of 5.5% and 94.0%, respectively. When segmented by spinal region, complication rates may be moderately positively correlated with frequency of cervical and thoracic procedures (r = 0.25, P = 0.68). The most commonly reported complication was pedicle screw malposition or breach. A subset of 20 studies, totaling 1554 patients, compared the performance of 3D navigation to two-dimensional fluoroscopy or freehand navigation. There was a significant difference of 6.53% between surgical success rates of the 3D-navigated and control groups (P = 0.03). However, there was no significant difference in radiation exposure or operative time.

CONCLUSIONS

The 3D navigation in spinal procedures has higher surgical success rates than two-dimensional fluoroscopy and freehand navigation. Included studies exhibited varying limitations, including no patient follow-up (n = 1), less than 10 patients (n = 6), various types of spinal disorders (n = 1), and varying comorbidities among participants (n = 2). Improving 3D navigation tools remains imperative to decrease operative time and radiation exposure.

Complications and Health-Related Quality of Life in Children with Various Etiologies of Early-Onset Scoliosis Treated with Magnetically Controlled Growing Rods-A Multicenter Study

Background: Early-onset scoliosis (EOS) refers to spinal deformities that develop and are diagnosed before the age of 10. The most important goals of the surgical treatment of EOS are to stop the progression of curvature, achieve the best possible correction, preserve motion, and facilitate spinal growth. The objectives of this multicenter study were to analyze the risk of complications among patients with EOS treated using magnetically controlled growing rods (MCGRs) and assess the patients' and their parents' quality of life after diagnosis and treatment with a minimum two-year follow-up. Methods: Patients given an ineffective nonoperative treatment qualified for surgery with MCGRs. This study involved 161 patients (90 females and 71 males) who were classified according to the etiology of curvature. The intraoperative and postoperative complications and those that occurred during the continuation of treatment with MCGRs were recorded and analyzed. The 24-item Early-Onset Scoliosis Questionnaire (EOSQ-24) was used to evaluate the patients' quality of life and satisfaction with the treatment. Results: Implant-related complications requiring instrumentation revision were recorded in 26% of the patients. Medical complications occurred in 45% of the population. The EOSQ-24 revealed a significant improvement in the average scores during the follow-up. Conclusions: The treatment of early-onset scoliosis with MCGRs carries 66% risks of incurring medical and mechanical complications, the latter 26% of patients requiring revision procedures. Children with neuromuscular scoliosis, females, and with curvature greater than 90 degrees are at a higher risk of developing complications. Limiting the number of elective surgeries necessitated to prolong the instrumentation and treatment process for patients with MCGRs can greatly enhance their quality of life and satisfaction throughout the follow-up period.

Factors associated with increased length of stay and risk of complications in 336 patients submitted to spine surgery. The role of a validated capture system (SAVES v2) as a first-line tool to properly face the problem

PURPOSE

In this study, we analyzed the use of a validated capture system (Spinal Adverse Events Severity system, SAVES V2) as a first non-technical skill to properly face the relevant problem of surgical complications (SCs) and adverse events (AEs) in spinal surgery.

METHODS

We retrospectively collected AEs occurring in a tertiary referral center for spine surgery from January 2017 to January 2018 and classified them according to SAVES V2 system. We compared this collection of AEs with a prospective collection performed without any classification system. Univariate and multivariate logistic regression models were used to determined odds ratio (ORs) for selected potential risk factors of AEs and prolonged length of stay.

RESULTS

Overall a higher number of AEs was retrospectively recorded using SAVES system compared to the prospective recording without the use of any capture system (97/336 vs 210/336, p < 0.001). The length of stay (LOS) increased in the group of complicated patients for all the procedures examined. In the non-oncological group, LOS was significantly higher for complicated patients compared to uncomplicated patients (F = 44.11, p = 0.0000). Similar results have been obtained in the oncological group of patients. In the multivariate regression model surgical time and postoperative AEs emerged as risk factors for prolonged LOS, while only the presence of previous surgeries was confirmed as risk factor for AEs.

CONCLUSION

Considering that the rate of AEs and SCs in spinal surgery is still high despite the improvement of technical skills, we suggest the use of SAVES V2 capture system as a first-line tool to face the problem.

Acute complications in open/miss primary and revision thoracolumbar spine surgery: a descriptive study of the most common complications and treatment of choice

PURPOSE

Main question The aim of this study is to describe and analyze the frequency of acute perioperative (intraoperatively and 30 days after) complications of open/MISS thoracolumbar spine surgery. Secondary questions A) Describe the treatment of choice for every kind of complication mentioned. B) Perform a bibliographic search and compare the complications described and their frequency with those studied in the manuscript.

METHODS

A retrospective cohort of 816 patients undergoing spinal surgery over a two year period was analyzed. Acute complications of 59 patients are described whether those with a greater number of levels required longer periods of hospitalization.

RESULTS

The frequency of acute complications was 7.2%. The most common was infection (2.7%), followed by dural tear (1.7%), and screw malpositioning (1%), which is consistent with the current literature. No statistically significant results were observed when comparing the mean length of hospital stay among patients operated on a greater number of levels compared to the rest (P: 0.344; 95% CI: -3.88-10.93).

CONCLUSIONS

The subsidiary patient of spinal surgery is getting older and has more comorbidities, and therefore, has a higher risk of complications. Although there are models predicting the risk of complications, they are not used in routine clinical practice. It would be necessary to unify the main criteria and establish guidelines for risk detection and therapeutic algorithms based on new high-quality studies.

State-of-the-Art of Non-Radiative, Non-Visual Spine Sensing with a Focus on Sensing Forces, Vibrations and Bioelectrical Properties: A Systematic Review

In the research field of robotic spine surgery, there is a big upcoming momentum for surgeon-like autonomous behaviour and surgical accuracy in robotics which goes beyond the standard engineering notions such as geometric precision. The objective of this review is to present an overview of the state of the art in non-visual, non-radiative spine sensing for the enhancement of surgical techniques in robotic automation. It provides a vantage point that facilitates experimentation and guides new research projects to what has not been investigated or integrated in surgical robotics. Studies were identified, selected and processed according to the PRISMA guidelines. Relevant study characteristics that were searched for include the sensor type and measured feature, the surgical action, the tested sample, the method for data analysis and the system's accuracy of state identification. The 6DOF f/t sensor, the microphone and the electromyography probe were the most commonly used sensors in each category, respectively. The performance of the electromyography probe is unsatisfactory in terms of preventing nerve damage as it can only signal after the nerve is disturbed. Feature thresholding and artificial neural networks were the most common decision algorithms for state identification. The fusion of different sensor data in the decision algorithm improved the accuracy of state identification.

Biomechanical considerations of the posterior surgical approach to the lumbar spine

BACKGROUND CONTEXT

The effect of the posterior midline approach to the lumbar spine, relevance of inter- and supraspinous ligament (ISL&SSL) sparing, and potential of different wound closure techniques are largely unknown despite their common use.

PURPOSE

The aim of this study was to quantify the effect of the posterior approach, ISL&SSL resection, and different suture techniques.

STUDY DESIGN

Biomechanical cadaveric study.

METHODS

Five fresh frozen human torsi were stabilized at the pelvis in the erect position. The torsi were passively loaded into the forward bending position and the sagittal angulation of the sacrum, L4 and T12 were measured after a level-wise posterior surgical approach from L5/S1 to T12/L1 and after a level-wise ISL&SSL dissection of the same sequence. The measurements were repeated after the surgical closure of the thoracolumbar fascia with and without suturing the fascia to the spinous processes.

RESULTS

Passive spinal flexion was increased by 0.8±0.3° with every spinal level accessed by the posterior approach. With each additional ISL&SSL resection, a total increase of 1.6±0.4° was recorded. Suturing of the thoracolumbar fascia reduced this loss of resistance against lumbar flexion by 70%. If the ISL&SSL were resected, fascial closure reduced the lumbar flexion by 40% only. In both settings, suturing the fascia to the spinous processes did not result in a significantly different result (p=.523 and p=.730 respectively).

CONCLUSION

Each level accessed by a posterior midline approach is directly related to a loss of resistance against passive spinal flexion. Additional resection of ISL&SSL multiplies it by a factor of two.

CLINICAL SIGNIFICANCE

The surgical closure of the thoracolumbar fascia can reduce the above mentioned loss of resistance partially. Suturing the fascia to the spinal processes does not result in improved passive stability.

Intraoperative tissue classification methods in orthopedic and neurological surgeries: A systematic review

Accurate tissue differentiation during orthopedic and neurological surgeries is critical, given that such surgeries involve operations on or in the vicinity of vital neurovascular structures and erroneous surgical maneuvers can lead to surgical complications. By now, the number of emerging technologies tackling the problem of intraoperative tissue classification methods is increasing. Therefore, this systematic review paper intends to give a general overview of existing technologies. The review was done based on the PRISMA principle and two databases: PubMed and IEEE Xplore. The screening process resulted in 60 full-text papers. The general characteristics of the methodology from extracted papers included data processing pipeline, machine learning methods if applicable, types of tissues that can be identified with them, phantom used to conduct the experiment, and evaluation results. This paper can be useful in identifying the problems in the current status of the state-of-the-art intraoperative tissue classification methods and designing new enhanced techniques.

Minimally Invasive Spine Stabilization for Pyogenic Spondylodiscitis: A 23-Case Series and Review of Literature

Background and Objectives: The incidence of pyogenic spondylodiscitis has been increasing due to the aging of the population. Although surgical treatment is performed for refractory pyogenic spondylodiscitis, surgical invasiveness should be considered. Recent minimally invasive spine stabilization (MISt) using percutaneous pedicle screw (PPS) can be a less invasive approach. The purpose of this study was to evaluate surgical results and clinical outcomes after MISt with PPS for pyogenic spondylodiscitis. Materials and Methods: Clinical data of patients who underwent MISt with PPS for pyogenic spondylitis were analyzed. Results: Twenty-three patients (18 male, 5 female, mean age 67.0 years) were retrospectively enrolled. The mean follow-up period was 15.9 months after surgery. The causative organism was identified in 16 cases (69.6%). A mean number of fixed vertebrae was 4.1, and the estimated blood loss was 145.0 mL. MISt with PPS was successfully performed in 19 of 23 patients (82.6%). Four cases (17.4%) required additional anterior debridement and autologous iliac bone graft placement. CRP levels had become negative at an average of 28.4 days after surgery. There was no major perioperative complication and no screw or rod breakages during follow-up. Conclusions: MISt with PPS would be a less invasive approach for pyogenic spondylodiscitis in elderly or immunocompromised patients.

Transient L5 Nerve Root Palsy Caused by Subfascial Drain After Lumbar Surgery: Case Report and Literature Review

CASE

We describe the case of a 45-year-old woman who developed a transient L5 deficit after a posterior L4-L5 interbody fusion. A perfusion computed tomography scan ruled out all described causes of postoperative deficit and showed compression of the right L5 root by the subfascial drain. The deficit spontaneously resolved.

CONCLUSION

New neurological deficit after spine surgery is a complication that requires a quick diagnostic and therapeutic approach. This particular case is of interest not only because it describes a rarely reported complication (transient neurological motor deficit after posterior fusion) but also because the hypothesized cause has never been described before.

Quality Assessment for Reporting Complications and Adverse Events in Spinal Surgery: A Proposed 5-Item Checklist

BACKGROUND

Reporting complications and/or adverse events after spinal surgical procedures enables the estimation of their prevalence and of their impact on patient outcomes. However, the documentation of complications is relatively infrequent and highly heterogeneous. The purpose of this study was to evaluate the quality of complication and adverse event reporting in spinal surgery literature.

METHODS

A systematic review of the literature from 5 international, peer-reviewed, indexed spinal journals was performed. Included studies were published between January and December 2020 and reported the surgical results of spinal procedures. Data on the level of evidence and study design were collected and analyzed as well as whether the studies were single-center or multicenter studies. The quality of complication reports was evaluated through a 5-item checklist, with 5 questions divided into 3 parts: definition, evaluation, and report.

RESULTS

Complications associated with spinal surgical procedures were reported in 292 studies. According to the level of evidence, significantly higher reporting quality was seen in level I and II studies compared with level III and IV studies (P = 0.003). Regarding the 5-item checklist, 49% (143/292) of studies fulfilled the definition section, 16.4% (48/292) fulfilled the evaluation section, and 92% (270/292) fulfilled the report section.

CONCLUSIONS

Overall quality assessment when reporting complications in surgical spinal studies showed that only 13% (38/292) of publications that reported complications as part of the outcomes exhibited all items of the 5-item checklist. Additionally, significantly better reports were observed in level I studies compared with level II-IV studies.

Multilayer Mattress Stitches for Complicated Wounds in Spine Surgery

Introduction

Local infection and prolonged fluid discharge account for most complications in lumbar spine surgery. This report is a brief description of a useful technique for revision of complicated, draining wounds with surprisingly positive results that otherwise frequently require multiple surgical interventions.

Technical Note

We describe the postoperative course of three patients, with prolonged and continuous serosanguineous discharge from the skin incision, who underwent wound revision with multilayered mattress stitches after open decompressive or instrumented spinal surgery. For this purpose, a thick monofilament suture is passed through the skin, subcutaneous fatty tissue, and paravertebral muscle in the fashion of a vertical mattress stitch while the loop above the skin level is augmented using a soft silicone capillary drainage to distribute tension along the wound margin.

Conclusions

None of the patients treated with the multilayered mattress stitches required further surgical intervention. In this small case series, the multilayered mattress stitches augmented with soft silicone tubing were a useful technique for treating complicated lumbar surgical wounds with prolonged serosanguineous discharge.

Towards markerless surgical tool and hand pose estimation

Purpose: 

Tracking of tools and surgical activity is becoming more and more important in the context of computer assisted surgery. In this work, we present a data generation framework, dataset and baseline methods to facilitate further research in the direction of markerless hand and instrument pose estimation in realistic surgical scenarios.

Methods: 

We developed a rendering pipeline to create inexpensive and realistic synthetic data for model pretraining. Subsequently, we propose a pipeline to capture and label real data with hand and object pose ground truth in an experimental setup to gather high-quality real data. We furthermore present three state-of-the-art RGB-based pose estimation baselines.

Results: 

We evaluate three baseline models on the proposed datasets. The best performing baseline achieves an average tool 3D vertex error of 16.7 mm on synthetic data as well as 13.8 mm on real data which is comparable to the state-of-the art in RGB-based hand/object pose estimation.

Conclusion: 

To the best of our knowledge, we propose the first synthetic and real data generation pipelines to generate hand and object pose labels for open surgery. We present three baseline models for RGB based object and object/hand pose estimation based on RGB frames. Our realistic synthetic data generation pipeline may contribute to overcome the data bottleneck in the surgical domain and can easily be transferred to other medical applications.

Supplementary Information

The online version supplementary material available at 10.1007/s11548-021-02369-2.

Real-time acoustic sensing and artificial intelligence for error prevention in orthopedic surgery

In this work, we developed and validated a computer method capable of robustly detecting drill breakthrough events and show the potential of deep learning-based acoustic sensing for surgical error prevention. Bone drilling is an essential part of orthopedic surgery and has a high risk of injuring vital structures when over-drilling into adjacent soft tissue. We acquired a dataset consisting of structure-borne audio recordings of drill breakthrough sequences with custom piezo contact microphones in an experimental setup using six human cadaveric hip specimens. In the following step, we developed a deep learning-based method for the automated detection of drill breakthrough events in a fast and accurate fashion. We evaluated the proposed network regarding breakthrough detection sensitivity and latency. The best performing variant yields a sensitivity of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$93.64 \pm 2.42$$\end{document}93.64±2.42% for drill breakthrough detection in a total execution time of 139.29\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\hbox { ms}}$$\end{document}ms. The validation and performance evaluation of our solution demonstrates promising results for surgical error prevention by automated acoustic-based drill breakthrough detection in a realistic experiment while being multiple times faster than a surgeon’s reaction time. Furthermore, our proposed method represents an important step for the translation of acoustic-based breakthrough detection towards surgical use.

Disproportionate Case Reduction After Ban of Elective Surgeries During the SARS-CoV-2 Pandemic

STUDY DESIGN

This is a retrospective case analysis.

OBJECTIVE

The objective of this study was to illustrate the numerical effects of regulatory restrictions of elective surgery at an orthopaedic university hospital.

SUMMARY OF BACKGROUND DATA

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic all over the world places extraordinary demands on health care systems which are forced to ensure structural and personnel capacities. Consequently, hospitals may only perform urgent interventions. Spine patients, however, often need urgent surgery and, moreover, bear an above-average perioperative risk frequently requiring postoperative surveillance on intensive care units (ICUs). Facing this dilemma, we want to share our practice and its unexpected numerical effects.

METHODS

We compare case statistics during normal operation, directly before and after implementation of regulatory measures. We also analyzed the differences in ICU utilization, complexity and duration of interventions and the patient population.

RESULTS

Spine surgical interventions have been reduced by 42.7%. Regulatory restriction of "elective surgeries" in pandemic situations results in reduced ICU utilization, however in a disproportionate manner. Although other specialized surgeries can be reduced by 59%, surgical spine cases are only diminishable by 24%. The spine surgery-related ICU occupancy has been reduced by 35%.

CONCLUSION

The disproportionate effect of case reduction needs to be considered while calculating resources released by regulatory limitation of "elective surgeries" on a (inter-)national level.