Spinal Exposure Research Articles

Perioperative Outcomes Related to Thoracic and Lumbar Spine Exposure During Vertebral Body Tethering for Adolescent Idiopathic Scoliosis: A Large, Single-institution Retrospective Review

BackgroundVertebral body tethering (VBT) is a novel non-fusion technique for the management of scoliosis. Despite growing popularity, data concerning complications and thoracic surgery-related outcomes are lacking. MethodsA single-institution retrospective review was conducted of patients who underwent VBT with video-assisted thoracic surgical exposure from 1/1/2015–3/1/2022. Data obtained included demographics, comorbidities, hospital course, and outcomes. Results106 patients (81 % female) were identified with a mean age at surgery of 12.7 ± 1.5 (range 9–16). Most patients underwent single curve tethering (n = 93, 87.7 %) with a mean number of vertebral bodies tethered of 8.0 (range 5–13). The mean operative time was 236 ± 96 min (range 129–661) minutes with an estimated blood loss of 165 ± 143 mL (range 20–750) and no patients required allogeneic blood transfusion. The extent of tethering was significantly associated with increased operative time, fluids received, and chest tube output. Excluding instrument-related complications, the complication rate was 13.2 %, mostly occurring within the first 30 days after surgery and pleural effusion being the most common event. Two patients experienced a postoperative hemothorax requiring reoperation. No patients experienced sequelae of spinal cord ischemia secondary to the division of intercostal and/or lumbar vessels during surgical exposure and no deaths occurred. ConclusionVBT is a seemingly safe alternative to spinal fusion in skeletally immature adolescents, however, there are notable complications of this procedure related to thoracic exposure. Our experience indicates clinically significant pulmonary complications are uncommon and the extent of vertebral body exposure/tethering was strongly associated with operative duration, fluids, and chest tube output. Levels of EvidenceThis original article represents a treatment study of Level IV evidence.

The Readiness Imperative: Leveraging Large Animal Resident Research to Enhance Expeditionary Surgical Skills.

The Defense Health Agency aims to ensure that military surgical residents have the expeditionary general surgical skills necessary to deploy to a combat environment and maintains the Clinical Investigation Programs (CIPs) that foster research during graduate medical education. This project evaluates the potential to achieve both aims simultaneously through a large animal Combat Casualty Care Research Program (CCCRP). Large animal experimental protocols within a single CIP's CCCRP were collected from July 1, 2017, to June 30, 2022. Operations performed were tabulated and categorized by Emergency General Surgery procedure equivalent. In addition, procedures performed by a single resident from July 1, 2020, to June 30, 2022, were separately indexed for a more granular analysis. The results are presented with total 5-year numbers listed first, followed by single resident 2-year numbers in parentheses. The residents at the CIP carried out 8676 (1,609) tabulated procedures. Major surgical procedures included 573 (154) laparotomies, 364 (129) thoracotomies, 279 (125) splenectomies, 219 (108) craniotomies, 206 (81) hepatorrhaphies, 363 (62) nephrectomies, 383 (48) bowel resections, 215 (48) spine exposures with laminectomies, and 173 (9) sternotomies. Additional procedures included 1028 (127) central venous lines, 878 (127) arterial lines, 90 (67) tube thoracostomies, 199 (37) carotid artery exposures, 394 (29) suprapubic urostomies, and placement of 278 (10) aortic occlusion catheters. At this time, the residents had 17 (10) presentations at national meetings, 8 (7) research awards, and published 20 peer-reviewed manuscripts. Additionally, the residents involved in the CCCRP gained valuable experience in critical care, including management of 110 traumatic brain injuries, 121 Intercranial Pressure catheters, 316 cases of hemorrhagic shock, and 211 massive transfusion protocols, among a variety of other vital critical care skills. This large animal CCCRP represents a unique training model that not only achieves its primary goal of fostering graduate medical education research but also bolsters Emergency General Surgery readiness for military surgical residents.

Identification of Deep Cervical Fascial Layers During Anterior Cervical Spine Exposure.

Anterior approaches to the cervical spine are among the most common exposures by which neurosurgeons and orthopedic surgeons access the prevertebral space and ultimately the cervical disk and vertebral bodies. There is a paucity of literature describing the microanatomic fascial planes of the neck with respect to anterior cervical approaches. To delineate the microanatomic connections of the cervical fascial planes pertinent to anterior cervical exposure. Using a cadaveric model, original illustrations, the Visible Human Project, and an original surgical video, we demonstrate a stepwise method for identifying the correct planes for anterior cervical exposure. A step-by-step method for identifying the anterior cervical fascial planes intraoperatively is demonstrated. A comprehensive understanding of anterior cervical microsurgical anatomy is vital for performing a methodical yet efficient approach to the prevertebral space while minimizing retraction and iatrogenic injury to the surrounding neurovascular structures.

P31. How positive cultures affected clinical outcomes in patients undergoing primary lumbar fusion

<h3>BACKGROUND CONTEXT</h3> Occult bacteria have been linked to deep and chronic infections in spine surgery. These organisms are commensal to dermal and deeper tissue layers, including the intervertebral disc and bone. We hypothesize that standard surgical skin preparation nor preoperative antibiotics properly access and eradicate these organisms prior to primary spine surgery. These organisms can potentially adhere to the biofilm surrounding the hardware and limit bone formation. <h3>PURPOSE</h3> To determine the colonization rate of occult bacteria in the superficial and deep tissue layers of healthy patients undergoing primary instrumented lumbar spine surgery. <h3>STUDY DESIGN/SETTING</h3> This prospective, consecutive cohort of patients undergoing primary lumbar spine surgery at a single tertiary center. All patients met the inclusion/exclusion criteria which included between the ages of 18 and 80, undergoing a posterior approach with pedicle screw instrumentation with no evidence of a prior or current fracture, trauma, tumor, or an active systemic or local infection. Patients were also excluded if they were immunosuppressed or had received prior surgery at any lumbar level with hardware. This study was approved by our institutional review board and ethics review panel. <h3>PATIENT SAMPLE</h3> Fifty-four patients. <h3>OUTCOME MEASURES</h3> Culture swabs, fusion rates, revision rates. <h3>METHODS</h3> All patients received preoperative antibiotics and skin preparation. Culture samples were subsequently obtained from the superficial skin, dermal wound-edge following incision, hypodermis and the vertebral pedicle prior to instrumentation implantation. Control culture samples were taken from scalpel, tap and suction prior to incision. The primary outcome was the rate of positive culture samples from the various layers traversed during standard surgical spine exposure. Clinical outcomes of fusion status and revision rate were collected. <h3>RESULTS</h3> A total of 525 culture samples were obtained, and samples were positive in 33.3% of patients (18/54). Culture-positive patients had on average 3.1 positive samples per case. Superficial skin samples were positive in 13.0% (n=7), dermal layer samples in 16.7% (n=9), hypodermis samples in 13.0% (n=7), and vertebral samples in 20.4% (n=11) of cases. All control samples taken were culture-negative. C. acnes was the most common organism isolated, in 83.3% of culture-positive cases. Significantly more males were culture-positive than females. Patients with positive cultures were treated with antibiotics. At one-year postoperative, patients in culture-positive group had similar fusion rates to culture-negative groups. However, delayed fusion was observed at a higher rate in the culture-positive group. <h3>CONCLUSIONS</h3> Occult bacteria was detected in one-third of patients undergoing primary instrumented posterior spine surgery. Deep culture samples of the vertebral pedicle were more often positive than dermal layer samples. The data collected supports our hypothesis that occult bacteria persist in the skin and deeper tissue layers regardless of the efforts made by preoperative skin preparation and prophylactic antibiotics. The clinical sequela for culture-positive patients, although addressed perioperatively, was a higher incidence of delayed fusion. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Patient Factors to Consider When Performing Spine Exposure for Anterior Approach as a Vascular Surgeon: An Analysis of the Nationwide Inpatient Sample

Anterior lumbar interbody fusion (ALIF) and posterior lumbar interbody fusion (PLIF) are common procedures indicated for degenerative disk disease and spondylolisthesis. The final determination of the surgical approach for lumbar spinal fusion is made by the spine surgeon, after which collaboration with a vascular surgeon is necessary for anterior exposure. To date, few comparative studies have investigated ALIF vs PLIF and their associated risks and outcomes, with even fewer studies that have investigated the surgical complication rates.

Anterior lumbar spine exposure with vascular surgeon assistance

Objective:Evaluate access related complications contributing to adverse outcomes in patients undergoing retroperitoneal anterior lumbar interbody fusion (ALIF). MethodsA retrospective analysis was conducted of prospectively collected data on patients undergoing ALIF in a multidisciplinary setting at our institution from January 2007 to December 2021. Patients’ demographics, comorbidities, exposure related and postoperative complications within 30 days were included. Main outcome measures included vascular and visceral injuries requiring repair, nerve injuries, blood transfusion requirements, myocardial infarction, stroke, erectile dysfunction, retrograde ejaculation, length of stay and death. ResultsSeventy-four consecutive patients were included. Forty-seven were female and 27 male. The median body mass index was of 25.46 ± 4.76. Mean age was of 45.74 years. Twelve had a history of previous abdominal surgery and 31 a previous spinal surgery. The level operated on was L5/S1 in 58 patients (78.37%), L4/L5 in 2 patients (2.7%) and multi-level in 14 patients (18.91%). Sixteen patients had both anterior and posterior approach. There were no major intra-operative vascular injuries. Two patients had an intestine serosal tear. Seven patients had sexual dysfunction after surgery, of which 5 suffered impotence and 4 retrograde ejaculation. Two patients had both. There were no cases of disc space infections. There were no postoperative deaths. ConclusionsIn a multidisciplinary setting, ALIF can be performed safely with a reasonably low overall complication rate. Impotence and retrograde ejaculation are, even if generally temporary, important issues that have to be informed to the patient and inquired at follow up.

Reoperative Anterior Lumbar Spine Access is Feasible and Safe

During the past two decades, the number of anterior lumbar spine reconstructions has increased significantly, as has the need for revisions and treatment of adjacent levels. We sought to determine the feasibility of reoperative anterior lumbar spine exposure. We performed a retrospective analysis of patients who had undergone repeat anterior extraperitoneal exposure of the lumbar spine from January 2009 to March 2021. Cases were excluded if reoperation had occurred within 1 month of the index procedure or if the reoperation had used a lateral approach. The demographic data and details on the operative procedure were analyzed. During the study period, 6130 procedures for anterior, oblique, or lateral exposure of the lumbar spine were performed. Within this cohort, 137 anterior reoperations were performed on 135 patients (mean age, 55.7 years; range, 19-83 years). The mean body mass index was 25.7 kg/m2 (range, 17-43 kg/m2). Most reoperations were remote from the index disc level (61%). The main indications for reoperation were adjacent level disease (n = 84), failed artificial disk repair (n = 25), and nonunion (n = 16). The approach was via the contralateral retroperitoneal space in 74, ipsilateral in 61, both sides in 1, and retro- and transperitoneal in 1. The median estimated blood loss for the 61 procedures performed without concomitant posterior reconstruction was 150 mL (range, 10-2050 mL). The procedure was aborted in seven cases (5%) because of the intraoperative anatomic findings. The levels successfully treated were L2-L3 in 16, L3-L4 in 26, L4-L5 in 30, L5-S1 in 88, and L6-S1 in 1. Artificial disk repair was performed at 33 levels and fusions at 128 levels. Two minor ureteral injuries occurred. Twenty venous injuries (15%) were primarily repaired. One patient required a venous stent for iatrogenic stenosis. Two internal iliac artery injuries were treated with ligation or repair. No patient died. Reoperative anterior spine exposure was successful in 95% of cases with relatively low morbidity and no mortality. Primary exposure of the L5-S1 level should be performed in the right retroperitoneal space to preserve the left side for adjacent level exposure. Ureteral catheters are recommended to assist in identifying the ureters when ipsilateral retroperitoneal exposure is required.

Identifying Risk Factors for Complications During Exposure for Anterior Lumbar Interbody Fusion.

IntroductionAn anterior approach to lumbar interbody fusion is a widely utilized method of access to the lumbar spine. Due to the potential for vascular complications with spine exposure, vascular surgeons are frequently included in the care of these patients as part of a team-based approach. Identifying risk factors for such complications is difficult and not well-defined in the literature. In this investigation, we evaluate the potential risk factors for complications during anterior lumbar inter-body fusion (ALIF).MethodsThis is a retrospective review of 106 patients who underwent ALIF at a single institution between May 1, 2007, and April 30, 2017. Patients were identified through operating room case logs and Current Procedural Terminology (CPT) codes correlating with ALIF. Vascular surgeons performed all anterior exposures. Patient demographics and data regarding their surgical care and postoperative course were obtained from a review of operative and progress notes in the electronic medical record. Statistical methods employed included a t-test for normally distributed data and the Wilcoxon rank-sum test for non-normally distributed data. Categorical variables were compared using Fisher’s exact and chi-square tests. A logistic regression model was applied to predict complications by controlling other significant covariates.ResultsOf the 106 patients included in this analysis, 16 patients experienced a defined complication, giving an overall complication rate of 15%. Patients with complications were more likely to be of male gender (n=11, P=0.016), with older average age (54.6, P=0.017), with higher estimated blood loss, with higher use of blood products, and with higher use of cell-saver. A venous injury was the most common complication (n=11, 10.4%); ileus and nerve injury were the next most common (n=3, 2.8%). The 30-day mortality was 0%. Male gender demonstrated an odds ratio of 3.78 (P=0 .034) in a logistic regression model after adjusting for age and blood products.ConclusionsOverall complication rates were comparable to those in the published literature and male gender was identified as a predictor for risk of complications in those undergoing ALIF. This is the first study to identify male sex as a risk factor for complications following ALIF. The results of this study will hopefully guide future studies in gaining more insight into the predictors of complications in larger series.

Retroperitoneal Exposure of the Anterior Lumbar Spine.

Anterior lumbar spine procedures such as anterior lumbar interbody fusion (ALIF) are used commonly to treat multiple pathologies, including pseudoarthrosis and degenerative disk disease. It is generally a safe and effective procedure, but an anterior approach to the lumbar spine requires critical navigation of the surgical window to avoid delicate structures. An operative technique should maximize the exposure without an increased risk of iatrogenic injury. To describe in detail a retroperitoneal exposure of the anterior lumbar spine. This surgical approach is a unique variation of standard anterior lumbar spine exposure techniques. This technique is described and illustrated in detail with an accompanying Supplemental Digital Content: video. Institutional Review Board (IRB) approval was not required because this is a variation of current techniques. Patient consent was obtained for the procedure and use of operative pictures and videos. Precise details of the technique are described. The surgical video demonstrates the technique for the L5-S1 ALIF approach. This technique is a novel variation of the standard retroperitoneal exposure of the anterior lumbar spine. The incision placement, size, and dynamic blunt retraction of this approach limit tissue disruption and provide an efficient exposure that has not been previously described in the literature.

Fewer Cardiopulmonary Complications and Shorter Length of Stay in Anterolateral Thoracolumbar Spine Exposures Using a Small-Incision Specialized Retractor System.

Objectives: One of the challenges of spine surgery is the need for adequate exposure of the anterolateral spinal column. Improved retractor systems with integrated lighting minimize the need for large thoracotomy, flank, or abdominal incisions. In 2013, we began using the NuVasive MaXcess® system via a minimal-access lateral incision for thoracic and thoracolumbar spine exposures. These small-access approaches may not offer adequate exposure when bleeding and other complications arise. We sought to determine the feasibility and outcomes of a minimal-access retractor during anterolateral spine exposures. Methods: An institutional-review-board-approved retrospective chart review was performed of all patients who underwent anterolateral thoracic and lumbosacral spine exposure at an academic hospital between December 1999 and April 2017. Cervical and posterior spine exposures were not included. Information regarding patient demographics, comorbid conditions, operative techniques, exposure, estimated blood loss, length of stay, and intraoperative and postoperative complications was collected. Data for standard exposure vs. minimally invasive exposures were compared. Results: Between December 1999 and April 2017, 223 anterolateral spinal exposures were performed at our institution. Of those, 122 (54.7%) patients had true lateral exposures, with 22 (18%) using the minimally invasive retractor. The mean age of our patient population was 57 years (19–89), with 65 (53%) men and a mean body mass index of 29.0 (17.4–58.6). In the standard exposure group, complications occurred in 22 (22%) patients, whereas only two (9%) complications occurred in the minimal-access group. There were no significant differences in overall intraoperative and postoperative complications, except for cardiopulmonary complications, which were reduced in the minimally invasive group (p < 0.019). Patients with minimally invasive exposure had a significantly shorter length of stay than those with standard exposure (7 vs. 13 days, p = 0.001). Conclusions: Minimal-access techniques using advanced retractor systems are both feasible and safe compared to standard techniques allowing for similar lateral spine exposure, but with smaller incisions, fewer cardiopulmonary complications, and shorter lengths of stay.

Contemporary Outcomes of Anterior Spine Exposure: The Influence of Prior Abdominal or Spine Surgery and Exposure Level and Extent

Anterior exposure of the lumbar spine (ALS) is a safe method to facilitate intervention in patients with spine disorders. Mobilization of vascular structures in patients with prior abdominal or spine interventions can be challenging and lead to morbidity. The objective of this study was to evaluate the impact of prior procedures on perioperative vascular complications (VCs). We retrospectively reviewed patients undergoing ALS from November 2015 to November 2019 at a single academic referral center. The primary end point was presence of VC (injury or thrombosis). During the 4-year period, 316 patients underwent ALS, most often through a left paramedian approach (54.4%). The most common operative indication was degenerative disease/deformity (97.5%). A total of 532 levels were exposed, the most frequent being L5-S1 (47.7%) and L4-L5 (32.0%), with 145 (45.9%) undergoing multilevel ALS. Mean age was 57 years, with 160 (50.6%) men and mean body mass index of 30.3 kg/m2. There were 150 (47.4%) patients who had prior abdominal surgery, and 172 (54.5%) had prior posterior spine surgery; 9 (2.8%) patients had prior ALS. Intraoperative VCs occurred in 31 (9.8%) patients (26 venous; 5 arterial). Of these, 87.1% occurred during L4-L5 ALS and 74.2% during multilevel ALS. In patients with VCs, 80.7% had prior abdominal or posterior spine surgeries; 80% (4/5) of arterial and 88.5% (23/26) of venous injuries involved ALS at L4-L5. Multilevel ALS accounted for 73.1% of venous injuries and all but one of the arterial injuries. Two VCs required patch repair, and the remaining 29 were minor injuries that were primarily repaired. Deep venous thromboses were diagnosed in 25 (7.9%) patients in the perioperative period. Of these, six (24%) had a venous injury repaired intraoperatively. Nineteen patients with deep venous thrombosis (76.0%) had ALS at L4-L5, with 18 (72.0%) having had multilevel ALS. In total, there were 56 total VCs (17.7%) with no arterial thrombosis. There were no perioperative deaths. In this series, ALS was often performed for multilevel disease, with a majority of patients having prior abdominal or spine procedures. Intraoperative VCs are minor and readily addressed. However, patients with prior abdominal or spine procedures appear to be the most susceptible to VCs. Caution should be taken while exposing the L4-L5 level, especially in multilevel spine exposure.

Contemporary Outcomes of Anterior Spine Exposure: The Influence of Prior Abdominal or Spine Surgery and Exposure Level and Extent

Anterior exposure of the lumbar spine (ALS) is a safe method to facilitate intervention in patients with spine disorders. Mobilization of vascular structures in patients with prior abdominal or spine interventions can be challenging and lead to significant morbidity. The objective of this study was to evaluate the impact of prior procedures on perioperative vascular complications.

Anterior Retroperitoneal Spine Exposure

Anterior surgical exposure of the lumbar spine has been increasingly performed by general and vascular surgeons over the past decade. Owing to the predominance of spinal pathology at the lower lumbar levels and the spinal surgeons’ need for assistance, the “exposure surgeon” has emerged. The knowledge and expertise for performing the anterior exposures lie within general surgery. Manipulation of the ureter, aorta, and iliac vessels must be done with precision and is an excellent opportunity for surgeons to use their expertise to aid the spinal surgeon. This review covers the relevant aspects of anterior surgical exposure of the spine. This review contains 8 figures, and 39 references. Key words: anterior lumbar interbody fusion, anterior retroperitoneal spine exposure, extraperitoneal, retroperitoneal, spondylolisthesis, spondylosis, total disk replacement

Predictors and Outcomes of Paramedian Incisional Hernia After Anterior Spine Exposure

BackgroundAnterior exposures for lumbar spine surgery are increasingly common for treating various spinal pathologies. A retroperitoneal approach via a paramedian incision has grown rapidly in popularity, but little is known about the risk of incisional hernia development with this technique. We sought to assess the incidence of paramedian incisional hernia development and identify risk factors that are associated with occurrence. Materials and methodsWe conducted a retrospective review of all patients who underwent anterior lumbar spine exposure by a paramedian approach between 2012 and 2017 at a single, tertiary medical center. The primary outcome was the development of postoperative paramedian incisional hernia. ResultsOf the 735 patients included in the study, 445 (60.5%) were women, and the mean (standard deviation) age of all patients was 60 y (12.4). Nearly all (97.4%) paramedian approaches were performed with a vascular surgeon present. Median follow-up time was 10 mo (interquartile range 3.5-19.9). Postoperative paramedian hernia developed in 20 patients (2.7%), of which 14 underwent repair. The mean (standard deviation) size of the hernia was 13.5 cm (5.5); 9 of 14 (64%) were repaired with synthetic mesh, whereas 3 of 14 (21%) required bowel resection. On multivariate analysis, risk factors associated with hernia development were male gender (0.045), higher American Society of Anesthesiologists class (0.039), history of abdominal surgery (P = 0.013), and postoperative intensive care unit admission (P = 0.02). ConclusionsA paramedian approach for anterior lumbar spine exposure resulted in a low rate of incisional hernia with minimal morbidity. Surgeons involved in these collaborative procedures should consider the risk factors that predispose patients to develop these hernias.

Cervical spinal cord injury associated with neck flexion in posterior cervical decompression -Verification by intraoperative spinal cord monitoring

Some unexplained postoperative paralysis have reported in the cervical spine surgery.We experienced several cases of intraoperative monitoring (IOM) warnings because of neck flexion in posterior cervical procedure. We investigated to evaluate preoperative factors in patients with spinal cord disorder due to flexion of the neck during posterior cervical spine surgery by changes in waveforms in IOM. A retrospective analysis of 179 consecutive patients who underwent IOM during posterior cervical spine surgery. When warning alarms were set off by amplitude changes in the period between skin incision and exposure of the lamina, the neck position was changed from flexion to neutral, and patients whose electrical potentials were recovered by a change in cervical position were placed in the flexion-induced potential reduction group. We analyzed to extract risk factors for flexion-induced reduction in potentials. 156 patients were analyzed in this study. A warning alarm went off in 7 patients (4.5%) at the time of posterior cervical spine exposure. However, by changing their neck position from flexion to neutral, the electrical potentials recovered in all patients, with no postoperative adverse events such as paralysis (flexion-induced potential reduction group) and the remaining 148 patients were used as controls. Logistic regression analysis was performed to identify the risk factors affecting the reduction of TCE-MEP. The two factors that were significantly associated with the risk of reduction of TCE-MEP were the occupying rate of anterior compression component at the most compressed level and Kyphotic angle in the flexion position of anterior compression component at the most compressed level.

Cervical Spinal Cord Injury Associated With Neck Flexion in Posterior Cervical Decompression

A retrospective analysis of prospectively collected data of 179 consecutive patients who underwent intraoperative neurophysiological monitoring during posterior cervical spine surgery for compression myelopathy. To evaluate preoperative factors in patients with deteriorating spinal cord function due to flexion of the neck during posterior cervical spine surgery by observing changes in waveforms on intraoperative monitoring. We encountered several cases of intraoperative monitoring warning alerts because of neck flexion during posterior cervical spine surgery. We investigated the incidence rate and intraoperative predictors of deteriorating spinal cord function caused by neck flexion based on waveform changes. Subjects were 179 patients who underwent posterior cervical decompression for spinal cord compression. When warning alarms were set off by amplitude changes in the period between skin incision and exposure of the lamina, the neck position was changed from flexion to neutral, and patients whose electrical potentials recovered following cervical repositioning were placed in the flexion-induced potential reduction group. We then analyzed and extracted risk factors for flexion-induced reduction in electrical potentials. In total, 156 patients were analyzed in this study. Monitoring alarms went off intraoperatively for 7 patients (4.5%) at the time of posterior cervical spine exposure. With regard to the most compressed level, the occupancy ratio of the anterior compression component, the kyphotic angle in flexion, and range of motion in the neutral position to flexion were significantly associated with flexion-induced reduction in electrical potentials. Furthermore, logistic regression analysis extracted the occupancy ratio of the anterior compression component at the most compressed level and the kyphotic angle of the most compressed level in flexion. Our findings suggest that a large anterior compression component and large kyphotic angle in neck flexion at the most compressed level are risk factors for intraoperative spinal cord injury during posterior cervical spine surgery.

Nasal soft tissue changes after two different approaches for surgically assisted rapid maxillary expansion

The aim of the study was to evaluate the nasal soft tissue changes in patients who underwent surgically assisted rapid maxillary expansion (SARME) using two different surgical approaches. Thirty-two patients were included in the study, and divided into two groups according to the type of surgical approach: in group A (n=17), SARME performed with standard Le Fort I circumvestibular approach with alar base cinch and anterior nasal spine (ANS) exposure; and in group B (n=15) operations were performed with the same standard Le Fort I circumvestibular approach with only alar base cinch. Measurements of height and width of the philtrum, nasal and subnasal width, and columella width were taken from three-dimensional facial images obtained before surgery (T1), after the distraction phase (T2) and 6 months postoperatively (T3). The mean maxillary expansion was 7.3±0.7mm for group A and 7.5±1.5mm for group B, without any significant difference between groups (P=0.59). Both groups presented an increase in all vaules in T2 and T3. The approach used in group A resulted in smaller changes in the columella width. The results of the present study show that there is no need for intraoperative releasing of the soft tissues around the anterior nasal spine during SARME if columella width is sufficient. However, further randomized studies based on large patient groups are needed before final conclusions on this topic can be reached.

Exploration of robotic-assisted surgical techniques in vascular surgery.

Robotic-assisted surgical approaches for vascular surgery are feasible regarding minimally invasive exposure, dissection, ligation and skeletonization for varicose vein ligation, anterior spine exposure, femoral-popliteal bypass, femoral vein harvest and aortic aneurysm repair. The authors performed a cadaveric exploration to demonstrate proof of concept and feasibility for a robotic-assisted approached. Surgeon autonomy over endoscopic vision, robotic instrumentation and retraction were noted as key benefits over existing open vascular approaches. Robotic-assisted approaches for vascular surgery enable innovative minimally invasive approaches to disease states not amenable to endovascular repair. Potential reductions in paresthesia through nerve identification were noted during a cadaveric exploration for varicose vein ligation in the setting of chronic venous insufficiency. Minimally invasive femoral artery exposure via a retroperitoneal approach could potentially reduce the morbidity associated with the traditional groin incision. Further exploration and procedure refinement are warranted.

Preclinical Comparison of Thermal Tissue Effects from Traditional Electrosurgery and a Low-Temperature Electrosurgical Device during Anterior Cervical Discectomy and Fusion.

Exposure of the anterior cervical spine requires dissection in proximity to critical neurovascular structures. Monopolar electrosurgical (ES) devices generate heat in contacted tissues, resulting in thermal damage and temperature change. This study examined depth of thermal injury and temperature change associated with use of a low-temperature electrosurgical device (LTD) compared to traditional electrosurgery during a cadaveric anterior cervical discectomy and fusion (ACDF) dissection. ACDF was performed, using ES or LTD, on cervical spines (C3-4 and C4-5) from 2 fresh human cadavers with intact neck soft tissues and no history of surgery. Cadavers were maintained at 22-23°C, and fiber-optic temperature sensors (Neoptix, Québec City, Québec, Canada) were placed near relevant structures to measure changes during dissection. Depth of thermal injury was assessed by hematoxylin and eosin and Masson's trichrome histology of fixed tissue specimens. Use of the LTD resulted in a statistically significant reduction in temperature change at platysma (3.0 ± 1.04 vs. 11.41 ± 3.10°C, P = .003), carotid sheath (7.32 ± 1.13 vs. 15.57 ± 2.56°C, P = .007), and longus colli (6.11 ± 1.32 vs. 12.9 ± 3.62°C, P = .016) compared to ES. Temperature change at the trachea was similar between groups (6.06 ± 1.99 vs. 4.96 ± 1.89°C, P = .528). Histology showed that LTD produced less mean and maximal depth of thermal injury compared to ES (mean: 0.5 vs. 1.2 mm; max: 0.9 vs. 1.8 mm; P < .05). The results of this pilot study demonstrate that anterior cervical spine exposure using an LTD reduces tissue temperature change and depth of thermal injury compared to ES. Although exploratory, these results suggest that use of an LTD during ACDF may reduce the extent of thermal tissue injury during dissection. Future studies in live animal models are warranted to determine if thermal injury is a potential cause of common exposure-related complications, such as dysphagia and dysphonia.

Incorporation of Anterior Lumbosacral Spine Exposure into a General Surgical Practice

Many spine surgeons enlist the aid of an "access surgeon" to provide anterior exposure of the lumbosacral spine. We proposed that a single, community hospital general surgery practice can successfully develop an anterior spine exposure program with acceptable clinical outcomes. One hundred and forty-three consecutive anterior exposures were performed between 2008 and 2014. Morbidity and 30-day mortality were recorded. The effects of American Society of Anesthesiologists Physical Status classification (ASA class) and number of levels exposed on length of stay (LOS) and estimated blood loss (EBL) was reported. The growth of the program during this period was also evaluated. During the six-year period, there were nine (6.3%) major complications and 17 (11.9%) minor complications with no 30-day mortality. The mean LOS was similar for one-level and two-level exposures (3.8 days). Mean LOS was higher in ASA III patients (4.4 days) than ASA I (2.9 days) or ASA II (3.2 days). Mean EBL for one-level exposures (336.3 mL) was not significantly different than EBL for two-level exposures (425.9 mL). EBLs in ASA class III patients were greater than in class I and class II patients. The program began in July of 2008 with a single spine surgeon and one operation that year. A high of 54 procedures, with seven different spine surgeons, was recorded in 2013. A single, community hospital general surgery practice can successfully develop an anterior approach to spine exposure program with acceptable clinical outcomes and with sustained growth of the program.