A minimally invasive tubular retractor-assisted retropleural approach for thoracic disc herniations - case series and technical note.

PURPOSE: Thoracic disc herniations are uncommon and carry a high risk for neurological deterioration. Traditional surgical approaches include thoracotomy, costotransversectomy or posterior approaches with considerable morbidity. In this technical note with case series, we describe a minimally invasive tubular retractor-assisted retropleural approach for simple and less invasive microsurgical exploration of thoracic disc herniations from a lateral angle. METHODS: Surgical technique consisted of partial rib resection and retropleural dissection followed by the placement of a tubular retractor (METRx Tubes, Medtronic) for an anterior-lateral exposure of the disc and neuroforamen. Epidemiological, clinical and surgical patient data were acquired. RESULTS: Between 2017 and 2020, six patients were surgically treated using the minimally invasive tubular retractor-assisted retropleural approach. Microsurgical exposure of the disc and neural structures was achieved from a lateral direction without requiring thoracotomy or lung deflation. Control imaging confirmed resection in all cases without relevant residuum. As postoperative complications, one dural injury and one postoperative pneumothorax occured. No neurologic deterioration or recurrence occurred during a median follow-up of 3 months. CONCLUSION: The described tubular retractor-assisted retropleural exposure serves as a feasible minimally invasive microsurgical approach to the anterior-lateral thoracic spine.

Operative results of AO A3 and A4 traumatic injuries in the thoracic and lumbar spine. A multicenter surveillance study of 4230 patients from the German Spine Registry (DWG-Register).

BACKGROUND: The diagnosis, classification and treatment of thoracolumbar burst fractures, continue to be controversial. Surgery is generally the preferred treatment for unstable fractures while stable fractures are managed conservatively. This study aims to describe surgical procedures, outcomes, complications, demography, clinical features and differences between A3 and A4 fractures (AO classification) of the thoracolumbar region. A subgroup of patients <91 years with osteoporotic fractures is included and analyzed. METHODS: Analysis of data from the DWG-Register German spine registry on operative treatment for thoracolumbar AO A3 and A4 fractures out of 170 departments from January 2017 to May 2021. The evaluated variables included age, gender, surgical approach (posterior, anterior combined), and re-operation. RESULTS: In total, 4230 AO A3 and A4 thoracolumbar fractures were identified in the registry; 2898 A3 (group 1) and 1332 A4 (group 2). The preoperative ASIA-impairment scale score in group 1 was significantly different compared with group 2 (P=0.02). Surgical procedures such as decompression/stabilization with rod-screw system cemented/non-cemented, as well as an anterior approach, were statistically significant between the groups. Odds ratio was calculated for variables that could be influenced for the type of fracture (A3 or A4): decompression 4.89, OR time >2 hours 48.22, osteoporosis 6.46 and posterior access 9.85. CONCLUSIONS: This study provides multicenter results from a huge number of surgically treated AO A3 and A4 fractures. Anterior approaches are more often used in A4 type fractures, probably because of its inherent instability related to burst fractures, surprisingly, not associated with the occurrence of added perioperative complications. Nevertheless, A3 type fractures are presented with worse ASIA Impairment-Scale at admission, in comparison with A4 type fractures of the thoracolumbar region.

Impact of Obesity on Perioperative Complications on Treatment of Spinal Metastases: A Multicenter Surveillance Study from the German Spine Registry (DWG-Register).

Background The spine is a common location for the development of primary and metastatic tumors, spinal metastases being the most common tumor in the spine. Spinal surgery in obesity is challenging due to difficulties with anesthesia, intravenous access, positioning, and physical access during surgery. The objective was to investigate the effect of obesity on perioperative complications by discharge in patients undergoing surgery for spinal metastases. Methods Retrospective analysis of data from the DWG-register on patients undergoing surgery for metastatic disease in the spine from January 2012 to December 2016. Preoperative variables included obesity (≥ 30 kg/m 2 ), age, gender, and smoking status. In addition, the influence of pre-existing medical comorbidity was determined, using the American Society of Anesthesiologists (ASA) score. Results In total, 528 decompressions with and without instrumentation undergoing tumor debulking, release of the neural structures, or tumor extirpation in metastatic disease of the spine were identified; 143 patients were obese (body mass index [BMI] ≥ 30 kg/m 2 ), and 385 patients had a BMI less than 30 kg/m 2 . The mean age in the group with BMI 30 kg/m 2 or higher (group 1) was 67 years (56.6%). In the group with BMI less than 30 kg/m 2 (group 2), the mean age was 64 years. Most of the patients had preoperatively an ASA score of 3 and 4 (patients with severe general disease). The likelihood of being obese in the logistic regression model seems to be protective by 47.5-fold for blood loss 500 mL or higher. Transfusions occurred in 321/528 (60.7%) patients (group 1, n = 122 and group 2, n = 299; p = 0.04). A total of 19 vertebroplasties with percutaneous stabilization (minimally invasive spine [MIS]), 6 vertebroplasties, and 31 MIS alone were identified. The variables between these groups, with exception of preoperative status (ASA-score; p = 0.02), remained nonsignificant. Conclusion Obese patients were predisposed to have blood loss more than 500 mL more often than nonobese patients undergoing surgery for spinal metastases but with perioperative blood transfusions, invasiveness, nor prolonged hospitalization. Early postoperative mobilization and a low threshold for perioperative venous thromboembolism (VTE) are important in obese patients to appropriately diagnose, treat complications, and minimize morbidity.

Invasiveness has no influence on the rate of incidental durotomies in surgery for multisegmental lumbar spinal canal stenosis (≥3 levels) with and without fusion: analysis from the German Spine Registry data (DWG-Register).

BACKGROUND: Nowadays, perioperative complications as dural tear (DT) with subsequent neurological deficits are documented in independent registers. However, the relationship of these complications with the grade of invasiveness (≥3 levels) is still unclear. The aim of this study was to evaluate perioperative complications, particularly DT with subsequent neurological deficits, between patients undergoing laminotomy and decompression and decompression and fusion in ≥3 levels. METHODS: Retrospective analysis of the data pool of the DWG register based on cases described by 10 clinics between January 2012 and December 2016 was performed. Surgically treated LSS in ≥3 segments were divided into decompression with or without instrumentation and fusion. Cases with intraoperative DT in both subgroups were analysed for risk factor occurrence. The Surgical Invasive Index (SII) was used. RESULTS: DT occurred in 102/941 (10.8%) patients. Difference in DT between groups was non-significant. The likelihood of DT increased by 2.12-fold with previous spinal surgery at the same level and by 1.9-fold for BMI 30-34 and >35 in comparison with BMI 26-29, respectively. Postoperative deep wound infection was increased by 2.39-fold after DT than without. Significance in outcomes between patients with/without DT was not found. The invasiveness index explained 48% of the variation in blood loss and 51% of the variation in surgery duration. CONCLUSIONS: The rate of incidental DT during decompression for LSS with and without fusion in ≥3 levels was associated with BMI and previous surgery at the same spinal level. Invasivness (SII) is valid rather for variables proper to surgery such as bledding and Op-time but no with incidence for DT and subsequent CSF-leackage.

Intra- and postoperative complications in the treatment of spinal metastases . A multicenter surveillance study from the German Spinal Registry (DWG-Register).

BACKGROUND: The incidence of spinal column tumors is estimated to be 0.62 per 100,000 individuals in the USA. It is especially important to understand the incidence and predictive factors for adverse events of surgery in spinal oncology patients, as a single complication may be associated with morbidity, mortality, and costs. The aim of the study was to use a large national registry to evaluate the perioperative cumulative incidence and predictors of major complications, for metastatic spinal tumors. METHODS: This study is a retrospective analysis of data from the DWG registry on patients who have undergone decompression with and without instrumentation undergoing tumor debulking, release of the neural structures, spinal stabilization or tumor extirpation in metastatic disease of the spine in 124 departments from January 2017 to January 2020, as well as vertebroplasty and percutaneous instrumentation. The outcomes evaluated were major complications defined by Finkelstein et al. as: death; cerebral (new postoperative coma or stroke), cardiac, pulmonary or renal complication; symptomatic venous thromboembolism; surgical site infection. RESULTS: In total, 1617 decompressions with and without instrumentation undergoing tumor debulking, release of the neural structures, spinal stabilization or tumor extirpation in metastatic disease in the spine were identified in the registry; N.=266 developed a major complication (group 2), while N.=1351 had no complication (group 1). The mean age in group 1 was 65 years (58.5%), in group 2 69 years (63.5%). In group 2, most of the patients had preoperatively an ASA Score of 3 and 4 (patients with severe general disease): 202/266 (75.9%) being significant. The overall prevalence of a major postoperative complication was 16.5% and for an intraoperative complication remained 8%. The likelihood ratio for major complications by blood loss greater than 500 mL were as follows: cardiovascular event with a likelihood of 4.22 pulmonary insufficiency 4.18 and cerebral 5.47. CONCLUSIONS: This analysis provides predictive models for surgeons to identify patients who may benefit from transitional care programs. Preoperative status, invasiveness, blood loss >500 mL and blood transfusions are independent predictors associated with higher risk of complication.

The degree of invasiveness has no influence on the rate of incidental durotomies in surgery for lumbar spinal canal stenosis: data from the German spine registry.

BACKGROUND: Risk factors for incidental durotomies are good documented by some authors who consider the degree of invasiveness as a direct risk factor on this serious complication. We compared the rate of incidental durotomies and its dependence from the degree of invasiveness. METHODS: The German Spine Registry could document 6016 surgeries for lumbar spinal canal stenosis, N.=2539 microsurgical decompression, and N.=2371 open decompression with stabilization. RESULTS: Both groups were identical concerning age and sex of patients, mean age: 77.1±1.60; females: 58%; males: 32%. There were 410 incidental durotomies, group 1: 209 (8.23%); group 2: 201 (8.47%). This difference is statistically not relevant (P=0,75). A surgical therapy is documented in 345 (84%) cases, suture with/without fibrin glue: group 1=162 and group 2=183. Fifty-nine patients had a persistent fistula that needed treatment with a lumbar drain, group 1: N.=30; and group 2: N.=29. CONCLUSIONS: The groups decompression vs. decompression plus fusion are statistically comparable. Although the stabilization with instrumentation is a more invasive procedure with longer operation times, trauma tissue and blood loss - in comparison with microsurgical decompression - showed no difference in the rate of incidental durotomies.

Incidence of early postoperative complications requiring surgical revision for recurrent lumbar disc herniation after spinal surgery: a retrospective observational study of 9,310 patients from the German Spine Register.

BACKGROUND: The recurrence rate in lumbar disc herniations (LDH) has been reported between 5 and 25%. There are only few data about this phenomenon that occurs within days of the initial operation. We analyse early recurrent LDH by analysis of data from the German Spine register. METHODS: Data from patients undergoing disc herniation surgery in the lumbar region were extracted from the German Spine Registry between 1st January 2012 and 31st December 2016. Patients with early recurrent LDH within days of initial surgery were separately analysed. RESULTS: A total of 9310 surgeries for LDH were documented in the German Spine Register. From these patients 115 (1.2%) presented an early recurrent disc surgeries within days of the initial surgery. The mean age was 70 ± 2.50 years. Most affected segment was L4/5 (47 cases, 41%), followed by L3/4 (45 cases, 39%). The most of our patients showed a normal or overweight Body Mass Index. Surgery for early recurrent LDH was associated with a high rate of incidental durotomies (20 cases, 17.6%). In 3 cases (2.6%) therapy with a lumbar drain was necessary. CONCLUSIONS: The rate of early recurrent LDH within days of surgery is 1.2%. Age seems to be an important factor in early recurrent LDH while obesity does not. The data of the German Spine Register seems to have a reliable data collection system that can perform multicentre data analysis. The databases from this Register could be used in the future for various purposes, such as the evaluation of multicentre surgical techniques, results in patients with various surgical procedures and basic research in spine surgery.

Hypocalcaemia as a prognostic factor of early mortality in moderate and severe traumatic brain injury.

OBJECTIVES: Our main objective was to evaluate whether serum hypocalcaemia on the third day [defined as < 2.1 mmol/l (8.5 mg/dl)] is a prognostic factor for early mortality after moderate and severe traumatic brain injury (TBI). METHODS: We developed an ambispective comparative case control study. We evaluated clinical profiles from included patients from January 2005 to July 2009 and we prospectively recruited additional patients from August 2009 to July 2011. Patients were between 1 and 89 years old and had a Glasgow Coma Scale of 3-12 points following TBI. RESULTS: We calculated an Odds Ratio of 5.2 (Confidence Intervals 95%: 4.48 to 6.032) for hypocalcaemia on day three, which was associated with death. Retrospectively (January 2005 to July 2009) we compiled data from 81 patients. Prospectively (August 2009 to July 2011) we recruited 41 patients. The adjusted variables in the logistic regression final model were: serum calcium on day three (Odds Ratio 3.5, Confidence Intervals 95%: 1·12 to 13·61, P < 0·028) and anisocoria (Odds Ratio 8·24, Confidence Intervals 95%: 1·3 to 67·35, P < 0·019) obtaining an adjusted R2 of 0·22 (P < 0·005). DISCUSSION: The serum levels of calcium on day three could be useful for the prediction of mortality in patients with moderate and severe TBI.

Degenerative cervical spinal stenosis: current strategies in diagnosis and treatment.

INTRODUCTION: Cervical spinal stenosis has become more common because of the aging of the population. There remains much uncertainty about the options for surgical treatment and their indications, particularly in cases of cervical myelopathy. METHODS: In order to provide guidance in clinical decision-making, the authors selectively reviewed the literature, according to the guidelines of the Association of Scientific Medical Societies in Germany. RESULTS: Cervical myelopathy is a clinical syndrome due to dysfunction of the spinal cord. Its most common cause is spinal cord compression by spondylosis at one or more levels. Its spontaneous clinical course is variable; most patients undergo a slow functional deterioration. Surgical treatment reliably arrests the progression of myelopathy and often even improves the neurological deficits. DISCUSSION: The available scientific data are too sparse to enable evidence-based treatment of cervical myelopathy. Early surgical intervention is often recommended in the literature. Controversy remains regarding the choice of the appropriate surgical procedure, but there is consensus on the suitable options for many specific clinical situations.

Degenerative lumbar spinal stenosis: current strategies in diagnosis and treatment.

INTRODUCTION: Although the aging of the population is causing a dramatic rise in the incidence of lumbar spinal stenosis, the indications and options for surgical treatment are not clearly defined. METHODS: In an attempt to aid clinical decision making, a selective literature review was conducted, taking into account the guidelines of the Association of the Scientific Medical Societies in Germany (AWMF). RESULTS: In degenerative lumbar spinal stenosis hypertrophy of the facet joints and yellow ligaments brings about constriction of the spinal canal, leading to back pain and activity-dependent lower limb symptoms (neurogenic claudication). If conservative treatment fails, an imaging study, usually magnetic resonance imaging, is required. In the case of severe symptoms the progressive underlying degeneration necessitates surgical treatment. Minimally invasive fenestration techniques are usually employed to decompress the spinal canal; in the presence of instability, fusion is indicated. DISCUSSION: Despite the proven superiority of surgery in the management of refractory lumbar spinal stenosis, there is a lack of evidence-based data regarding the different surgical treatment options. The evaluation of modern, minimally invasive techniques is thus difficult.