Soft Tissue Retraction Research Articles

Accelerated Frostbite-Induced Acroosteolysis in Pediatric Insensate Hand: A Case Report and Literature Review.

In pediatric patients, frostbite is a well-documented cause of epiphyseal cartilage destruction and subsequent growth deformity of the affected phalanges. Cases of full acroosteolysis, also referred to as phalangeal osteolysis, of distal phalanges as soon as three months after cold exposure have yet to be reported. We describe a complicated case of frostbite-associated phalangeal osteolysis in the dominant hand of a nine-year-old patient, in the context of post-traumatic insensate hand after sustaining prior electrical burn injuries. This case demonstrates the unique sequela of pediatric frostbite injury involving early loss of the distal phalanx through resorption of the bone and parallel soft tissue retraction, rendering early plastic surgery reconstruction impractical. Reconstructive strategies for frostbite injury in pediatric patients will need to account for the individualized dynamic tissue changes that develop in the months after cold exposure.

Optimizing revision arthroplasty: the role of customized articulating spacers

Introduction The advancement of surgery is set against a backdrop of continuous development and surgical innovations have transformed the way clinical care is delivered. Revision surgery might be required to address complications of primary arthroplasty. The first stage of revision arthroplasty would involve removal of an implant and placement of an antibiotic-impregnated cement spacer to maintain the joint space and stability, prevent soft tissue retraction, provide local antibiotic release and preserve bone tissue for revision implantation at the final stage of revision. Custom-made articulating spacers are a promising tool for optimizing the first stage of revision arthroplasty.The objective was to summarize the current data and present comprehensive information about spacers used in two-stage revision arthroplasty including manufacturing techniques, physical and chemical properties, clinical applications, the possibility of customization within the first stage of revision arthroplasty, current and promising directions for research.Material and methods The original literature search was conducted on key resources including Scientific Electronic Library (www.elibrary.ru), the National Library of Medicine (www.pubmed.org), the Cochraine Library (www.cochranelibrary.com) between 2018 and 2023 using search words and phrases: total arthroplasty, complications, revision arthroplasty, articulating spacer, periprosthetic joint infection, additive manufacturing, 3D printing.Results A comparative analysis of factory supplied, home-made, dynamic and static spacer models showed that the choice of articulating spacers for revision arthroplasty of major joints is of great relevance. Advantages of factory-made spacers include standardized range of sizes, the reliability and availability for medical institutions. They are characterized by limited use in repair of severe bone defects.Discussion Custom-made articulating spacers enable specific tailoring to accommodate individual defects. Despite high expectations from custom-made spacers, development of optimal technologies for rapid prototyping is essential. Investments in research and development in this area have the potential to create innovative solutions that can significantly improve the results of revision arthroplasty.Conclusion The paper explores the importance of systemization of knowledge about spacers and the role of new research in improving the design and functionality. Progress in the field of materials science, additive technologies and a personalized approach to spacer manufacturing can expand possibilities of revision arthroplasty and the effectiveness. Personalized approaches and improved methods of local drug delivery that provide controlled release of antibiotics can improve the results of treatment of periprosthetic joint infections.

Soft Tissue Retraction Maneuver in Cone Beam Computed Tomography Prior to Crown-Lengthening Procedure-A Technical Note.

Background: An accurate determination of the biological width and the relationship of the cemento-enamel junction with the border of the alveolar bone is crucial during a clinical crown-lengthening (CCL) procedure. The aim of this study was to present a technical note about the retraction techniques in cone beam computed tomography (CBCT) prior to CCL, highlighting the significant enhancement in procedural accuracy and predictability that these techniques offer. Methods: Clinical and radiological examinations should be performed before a CCL procedure. It is necessary to determine the length of the tooth crowns, the periodontal pockets' depth, and the phenotype of the gingiva. The ideal CBCT examination should be performed with soft tissue retraction. This can be achieved using retractors or cotton rolls. Results: Retraction of the lips, cheeks, and tongue allows one to assess the marginal gingiva, the cemento-enamel junction, and the alveolar bone. A detailed plan of the CCL procedure, which involves retraction, ensures both the aesthetic appeal and the achievement of a newly defined gingival zenith, enhancing the overall visual harmony. Conclusions: Compared with conventional radiographic imaging, the soft tissue retraction maneuver in CBCT prior to CCL surgery offers an effective approach to the evaluation and diagnosis of soft and hard tissue. This is because of the detailed planning of the aesthetic CCL procedure. Such an approach leads to superior aesthetic outcomes in dentistry, contributing to the advancement of aesthetic dentistry through a harmonious blend of art and science.

PLANTAR STRUCTURES IN RELATION TO A STRAIGHT RETROGRADE HIND FOOT (RHF) NAIL INSERTED THROUGH A MIDLINE HEEL PAD APPROACH: A CADAVERIC STUDY

BackgroundRHF nail is an important tool for simultaneous ankle and subtalar joint stabilisation +/− fusion. Straight and curved RHF nails are available to use, but both seem to endanger plantar structures, especially the lateral plantar artery and nerve and Baxter's nerve.There is a paucity of literature on the structures at risk with a straight RHF nail inserted along a line bisecting the heel pad and the second toe (after Stephenson et al). In this study, plantar structures ‘at risk’ were studied in relation to a straight nail inserted as above.MethodsRe-creating real-life conditions and strictly following the recommended surgical technique with regards to the incision and guide-wire placement, we inserted an Orthosolutions Oxbridge nail into the tibia across the ankle and subtalar joints in 6 cadaveric specimens. Tissue flaps were then raised to expose the heel plantar structures and studied their relation to the inserted nail.ResultsThe medial plantar artery and nerve were always more than 10mm away from the medial edge of the nail, while the Baxter nerve was a mean 14mm behind. The lateral plantar nerve was a mean 7mm medial to the nail, while the artery was a mean 2.3mm away with macroscopic injury in one specimen. The other structures ‘at risk’ were the plantar fascia and small foot muscles.ConclusionLateral plantar artery and nerve are the most vulnerable structures during straight RHF nailing. The risk to heel plantar structures could be mitigated by making incisions longer, blunt dissection down to bone, meticulous retraction of soft tissues and placement of the protection sleeve down to bone to prevent the entrapment of plantar structures during guide-wire placement, reaming and nail insertion.

Comparative Evaluation of Ease of Operator and Patient Acceptability Using the Traditional Isolation System vs a New Isolation Tool (Intraoral Cheek and Lip Retractor Mouth Opener Tool).

The aim of the study was to compare the traditional isolation method with the new isolation tool. A questionnaire pattern was adopted for the present study. The study was then conducted to evaluate the patient acceptability and ease of access for the operator. A total 200 pediatric patients were included in the study; they were divided into two groups. Group I-isolation with the new isolation tool, group II-isolation with cotton rolls and a mouth mirror. A structured questionnaire was given to the operators to evaluate the ease of use of the new isolation tool. A Likert scale was provided to the patients to evaluate the comfort of the new isolation tool during various treatments. Statistical analysis shows significant results by obtaining the p-value < 0.05. The study clearly shows that the new isolation tool is a better option in terms of retracting soft tissue, keeping the mouth open, and maintaining isolation. This new tool helps in the retraction of soft tissue as well as isolation, and it also keeps the mouth open. Chauhan KM, Sodani V, Sharma DJ, et al. Comparative Evaluation of Ease of Operator and Patient Acceptability Using the Traditional Isolation System vs a New Isolation Tool (Intraoral Cheek and Lip Retractor Mouth Opener Tool). Int J Clin Pediatr Dent 2024;17(6):637-640.

MID–TERM OUTCOMES OF ENDOSCOPIC MITRAL VALVE REPAIR VIA RIGHT ANTERIOR MINI–THORACOTOMY

Abstract The adoption of less–invasive mitral repair (MVr) surgery is increasing, backed by evidence of satisfactory short–term results and lower major morbidity. We assessed mid–term follow–up results of our experience, and compared two techniques: isolated leaflet resection and neochord implantation for posterior leaflet (PML) prolapse. Between 2012–2021, 700+ operations were performed with a video–assisted right mini–thoracotomy (RMT) approach. We report 309 consecutive patients who had endoscopic MVr, including those receiving concomitant tricuspid repair, ablation for atrial fibrillation, closure of patent foramen ovale and/or left atrial appendage. The early and mid–term follow–up results were ascertained. Primary outcome was the incidence of mortality and significant mitral regurgitation (MR) during follow–up which were summarized by Kaplan–Meier estimator and compared between treatment arms via log–rank test. Secondary outcomes were the early–postoperative results including 30–days mortality and major complications. All patients had endoscopic MVr via RMT at the 3rd/4th intercostal space (IS). A soft–tissue retractor is used, accompanied or not by a rib spreader, and two ports in the fourth and sixth IS are used for 3D thoracoscopy and carbon dioxide insufflation. Femoral vessels exposure through a right groin incision and echo–guided cannulation sec. Seldinger is achieved post–heparinization. Thoracic fascia bisection is performed during single–lung ventilation using a double–lumen endotracheal tube, integral to our anesthetic management, including percutaneous right internal jugular vein cannulation. The pericardium is opened and an aortic root cannula for cardioplegia delivery and venting is placed via working incision. After establishing cardiopulmonary bypass, a Chitwood clamp is passed through the second IS and cardioplegia is delivered. Endoaortic balloon clamping is primarily used in redo cases. With ring annuloplasty, 136 (44%) patients received PML resection (122 isolated) and 97 (31%) PML chords implantation (88 isolated). Forty–nine patients had annuloplasty alone. In–hospital mortality was 1.0%. Mean follow–up was 29±22 months (max 8.3 years). Kaplan–Meier 5–year survival was 97.3±1.0%. MR (3/4+) free–survival at 5 years was 94.5±2.3%. Subgroup time–to–event analysis for the indexed outcomes showed no statistical significance between techniques. In conclusion, endoscopic MVr is safe with excellent mid–term outcomes.

Evaluation of Clinical Success of the 3D-Printed Custom-Made Subperiosteal Implants.

The authors aim to share their experiences in subperiosteal implant applications in atrophic jaws, which have been practiced in their clinic for about 2 years, and evaluate the complications and clinical success of the implants. Clinical and radiologic data of 32 patients who underwent subperiosteal implantation for advanced alveolar bone loss were evaluated, but 1 patient was excluded as they smoked. Of the 31 patients included in the study, 27 were operated with the diagnosis of total tooth loss, 3 for maxillectomy and 1 for partial tooth loss. A total of 60 subperiosteal implants were placed in them. The mean follow-up period was 15 months. During the operation, implant-bone adaptation problems were encountered in 11 patients, implant skeletal fracture in 1 patient, and loss of primary stabilization during mini-screw fixation in 2. Although there were no complications in the early postoperative period, biological and prosthetic complications occurred in the late postoperative period. Soft tissue retraction at various levels in 12 patients (only keratinized tissue retraction in 6 and mucosal retraction exceeding keratinized tissue in 6), soft tissue infection in 5 and oroantral fistula development in 1, mini-screw loosening in 3 were the biological complications that occurred. Various complications may occur during or after the application of custom-made subperiosteal implants. However, these are manageable and can be reapplied in case of a possible implant loss, making it an important alternative, especially in atrophic jaws where endosseous dental implants cannot be applied.

Anterior soft tissue retraction during arthroscopy of the ankle

Ankle arthroscopy has been increasingly employed in recent times due to a wide variety of ankle pathologies and advances in indications and technology. We have described a technique of retraction of the anterior soft tissue structures that can be used during ankle arthroscopy that is easy, does not require special instruments, is quick to apply, and gains valuable tourniquet time by reducing interruptions caused by tissue interference and increasing the visual field.

Oblique lateral interbody fusion at L5-S1: feasibility, surgical approach window, incision line, and influencing factors.

The primary aim of this study was to describe the feasibility, surgical approach window (SAW), and incision line (IL) for oblique lateral interbody fusion at L5-S1 (OLIF51) using computed tomography (CT). A secondary aim was to identify associations among approach characteristics and demographic and anthropometric factors. We performed a radiographic study of 50 male and 50 female subjects who received abdominal CT imaging. SAW was measured as the distance from the midline to the medial border of the iliac vessel. IL was measured at the skin surface corresponding to the distance between the center of the disc space and SAW lateral margin. OLIF51 feasibility was defined as the existence of at least a 1-cm SAW without retraction of soft tissues. For the left side, the OLIF51 SAW and IL were 12.1 ± 4.6 and 175.1 ± 55.3mm. For the right side, these measures were 10.0 ± 4.3 and 185.0 ± 52.5mm. Correlations of r = 0.648 (p < 0.001) and r = 0.656 (p < 0.001) were observed between weight and IL on the left and right sides, respectively. OLIF51 was not feasible 23% of the time. To our knowledge, this is the largest CT study to determine the feasibility of performing an OLIF51. Without the use of retraction, OLIF51 is not feasible 23% of the time. Left-sided OLIF51 allows for a larger surgical approach window and smaller incision compared to the right side. Larger incisions are required for adequate surgical exposure in patients with higher weight.

Early outcome of endoscopic mitral valve surgery in elderly patients: a high-volume single center experience

IntroductionDespite increasing use of transcatheter approaches, endoscopic mitral valve surgery (MVS) remains an established option for treatment of mitral regurgitation (MR). Nevertheless, as perioperative risk increases with age, outcome of endoscopic MVS in elderly patients is uncertain.MethodsWe retrospectively analyzed 756 consecutive patients with MR ≥2, who underwent minimally-invasive MVS at our institution between 2016 and 2022. Patients were stratified by age ≥75 (elderly-group; n = 91) or &amp;lt;75 years (control-group; n = 665). All patients received endoscopic MVS via right anterolateral minithoracotomy with non-rib spreading soft tissue retraction and 3D-camera visualization.ResultsOverall surgical risk was increased in the elderly-group (median age of 77 (76–80) years vs. 58 (51–67) years, p &amp;lt; 0.001) with STS-PROM Scores of 1.9% vs. 0.4% (p &amp;lt; 0.001) and increased prevalence of hypertension, diabetes, coronary artery disease and atrial fibrillation (AFib). Elderly patients were also more symptomatic (NYHA class III 45.7% vs. 29.8%; p = 0.002). Axillo-femoral perfusion was more frequently used in the elderly-group (27.5% vs. 4.2%; p &amp;lt; 0.001). Cross-clamp and cardiopulmonary bypass times were similar. Rate of MV repair was 85.7% vs. 93.8% (p = 0.005). Closure of the left atrial appendage was more frequently performed in the elderly-group (45.1% vs. 23.9%; p &amp;lt; 0.001), whereas rate of concomitant tricuspid valve repair was similar (11.0% vs. 8.9%; p = 0.511). Postoperative complications including perioperative hemodialysis (3.3% vs. 2.9%; p = 0.739), low cardiac output (5.3% vs. 3.8%; p = 0.393), perioperative stroke (1.1% vs. 0.15%; p = 0.224) and myocardial infarction (0% vs. 0.15%) were favorably low in both groups. Acute mortality at 30 days was 2.2% vs. 0.4% (p = 0.112).ConclusionDespite increased prevalence of outcome-relevant comorbidities and surgical risk, perioperative outcome of patients aged ≥75 years undergoing endoscopic MVS is favorable. Therefore, endoscopic MVS is a valuable therapeutic option for selected elderly patients and should be taken in consideration during routine heart-team discussion.

Plasma Somatostatin Levels Increase during Scoliosis Surgery, but Not Herniated Disc Operations: Results of a Pilot Study.

Somatostatin (SST) released from capsaicin-sensitive sensory nerves in response to stimulation exerts systemic anti-inflammatory, analgesic actions. Its elevation correlates with the extent of tissue injury. We measured plasma SST alterations during spine operations (scoliosis and herniated disc) to determine whether its release might be a general protective mechanism during painful conditions. Sampling timepoints were baseline (1), after: soft tissue retraction (2), osteotomy (3), skin closure (4), the following morning (5). Plasma SST-like immunoreactivity (SST-LI) determined by radioimmunoassay was correlated with pain intensity and the correction angle (Cobb angle). In scoliosis surgery, postoperative pain intensity (VAS 2.) 1 day after surgery significantly increased (from 1.44 SEM ± 0.68 to 6.77 SEM ± 0.82, p = 0.0028) and positively correlated with the Cobb angle (p = 0.0235). The baseline Cobb degree negatively correlated (p = 0.0459) with the preoperative SST-LI. The plasma SST-LI significantly increased in fraction 3 compared to the baseline (p < 0.05), and significantly decreased thereafter (p < 0.001). In contrast, in herniated disc operations no SST-LI changes were observed in either group. The VAS decreased after surgery both in the traditional (mean 6.83 to 2.29, p = 0.0005) and microdiscectomy groups (mean 7.22 to 2.11, p = 0.0009). More extensive and destructive scoliosis surgery might cause greater tissue damage with greater pain (inflammation), which results in a significant SST release into the plasma from the sensory nerves. SST is suggested to be involved in an endogenous postoperative analgesic (anti-inflammatory) mechanism.

The advantages of a single use retractor for soft tissue protection in direct anterior approach total hip arthroplasty: the preliminary experience.

The anterior hip approach is a procedure with increasing popularity in hip replacement surgery due to its many benefits and the number of surgeons using it is steadily increasing around the world. Less pain, better results in the first few weeks, reduced dislocation rate are the prerogatives of this approach. We analyzed in a group of 26 patients the use of a soft tissue retractor, Alexis Orthopedic Protector, the CPK values in the first third and fifth postoperative day. The results obtained, normalized, demonstrate a slight reduction in tissue damage using the device compared to a control group. In addition to blood values, improved exposure, distribution of leverage, cleanliness of the field and a potential reduction in infectious risk are advantages for the use of an orthopedic surgery retractor. We believe that the adoption of the Alexis Orthopedic Protector provides numerous improvements during the hip arthroplasty surgical procedure, especially when adopting the direct anterior approach, because it distributes the traction forces around the surgical path resulting in greater visibility. However, the small number of patients is not sufficient to perform an accurate statistical analysis and further studies on larger samples will be required.

“Triple Package” Modified SpeedBridge Rotator Cuff Repair Technique

Treatment of full-thickness rotator cuff repairs vary in surgical technique depending on many factors including tear geometry, delamination of soft tissue, tissue quality, and rotator cuff retraction. The described technique presents a reproducible method of addressing tear patterns where the tear may be larger laterally, but the medial footprint exposure is small. This can be addressed with a single medial anchor combined with a knotless lateral-row technique to provide compression for small tears or two medial row anchors for moderate to large tears. In this modification of the standard knotless double row (SpeedBridge) technique, 2 medial row anchors are used, with 1 augmented with additional fiber tape and an additional lateral row anchor to create a triangular repair construct, increasing the size and stability of the footprint of the lateral row.

Using artificial intelligence to quantify dynamic retraction of brain tissue and the manipulation of instruments in neurosurgery.

There is no objective way to measure the amount of manipulation and retraction of neural tissue by the surgeon. Our goal is to develop metrics quantifying dynamic retraction and manipulation by instruments during neurosurgery. We trained a convolutional neural network (CNN) to analyze microscopic footage of neurosurgical procedures and thereby generate metrics evaluating the surgeon's dynamic retraction of brain tissue and, using an object tracking process, evaluate the surgeon's manipulation of the instruments themselves. U-Net image segmentation is used to output bounding polygons around cerebral parenchyma of interest, as well as the vascular structures and cranial nerves. A channel and spatial reliability tracker framework is used in conjunction with our CNN to track desired surgical instruments. Our network achieved a state-of-the-art intersection over union ([Formula: see text]) for biological tissue segmentation. Multivariate statistical analysis was used to evaluate dynamic retraction, tissue handling, and instrument manipulation. Our model enables to evaluate dynamic retraction of soft tissue and manipulation of instruments during a surgical procedure, while accounting for movement of the operative microscope. This model can potentially provide the surgeon with objective feedback about the movement of instruments and its effect on brain tissue.

Assessing Surgical Approaches for Acoustic Neuroma Resection: Do Patients Perceive a Difference in Quality-of-Life Outcomes?

The objective of this study is to further patient-physician discussion regarding postoperative quality of life expectations after surgical acoustic neuroma resection. This study is retrospective prospective. Qualifying patients were identified and administered Penn Acoustic Neuroma Quality-of-Life (PANQOL) Scale. The setting was Loyola University Chicago Health System. Three hundred twenty-six patients at our center with surgically resected acoustic neuroma between January 1990 and July 2021 completed the PANQOL. During postresection follow-up visits, patients were administered the PANQOL survey. The total PANQOL is comprised of questions addressing quality of life in seven domains of hearing, balance, face, energy, pain, health, and anxiety. Univariate and multivariable analyses were performed to test for associations between surgical approach and/or patient characteristics. Patients who were treated with retrosigmoid approach reported slightly higher PANQOL pain scores when compared with translabyrinthine approach. No association was found between responses on hearing PANQOL and surgical approach. No association was found between approach and total PANQOL score. However, on average female patients reported lower total PANQOL compared with male patients. The lack of association between patient response on hearing PANQOL and surgical approach illustrates the impact of preoperative patient counseling in appropriately setting patient expectations. The difference in pain PANQOL response may be due to a higher rate of occipital neuralgia due to incision placement and soft tissue retraction in the retrosigmoid patient group. Surgeons may consider alternative surgical incisions and soft tissue dissection to improve patient's quality of life with respect to postoperative pain.

Comparison of naproxen and combination therapy (naproxen and gabapentin) in post extraction pain relief.

Objective: To evaluate the efficacy of using combination drug treatment to relieve post extraction pain of impacted mandibular third molar by using Naproxen plus Gabapentin versus Naproxen alone. Study Design: Randomized Control study. Setting: Dental Clinic OPD of Bhitai Dental and Medical College, Sindh, Pakistan. Period: 1st December 2018 to 30th May 2019. Material &amp; Methods: The procedure for extraction was carried out under Local Anaesthesia (2% lignocaine hydrochloride with 1:100,000 adrenaline) at dental clinic OPD of Bhitai Dental and Medical College. Some extractions were performed in Closed Extraction technique while in some patients standard surgical procedure was used which consist of triangular muco – periosteal flap on buccal surface and lingual retraction of soft tissue followed by bone removal. For Pre – Operative and 24-Hour Post – Operative Pain status assessment Visual Analogue Scale and Wong Baker’s Face Pain Rating Scale. Results: Combination therapy (Naproxen and Gabapentin) was effective in significant pain reduction at 12 Hour and 24-Hour Post Extraction period. With 26 patients out 31 presented with Pain Scale of 0 on combination therapy while only 3 out of 31 for naproxen alone after 24 hours. All patients received a single dose of study medicines from the hospital pharmacy. In demographic data, there were 47% (n=29) males and 53% (n=33) females with mean age group of 27.89. Comparing the pain response between the genders, males presented slightly faster pain relief with time as to the females. Conclusion: Enhanced effect of combination therapy of naproxen with gabapentin in reducing post extraction pain of impacted mandibular third molar with respect to naproxen alone.

Magnetic Anchoring Considerations for Retractors Supporting Manual and Robot-Assisted Minimally Invasive Surgery

The rise and advancement of minimally invasive surgery (MIS) has significantly improved patient outcomes, yet its technical challenges—such as tissue manipulation and tissue retraction—are not yet overcome. Robotic surgery offers some compensation for the ergonomic challenges, as retraction typically requires an extra robotic arm, which makes the complete system more costly. Our research aimed to explore the potential of rapidly deployable structures for soft tissue actuation and retraction, developing clinical and technical requirements and putting forward a critically evaluated concept design. With systematic measurements, we aimed to assess the load capacities and force tolerance of different magnetic constructions. Experimental and simulation work was conducted on the magnetic coupling technology to investigate the conditions where the clinically required lifting force of 11.25 N could be achieved for liver retraction. Various structure designs were investigated and tested with N52 neodymium magnets to create stable mechanisms for tissue retraction. The simplified design of a new MIS laparoscopic instrument was developed, including a deployable structure connecting the three internal rod magnets with joints and linkages that could act as an actuator for liver retraction. The deployable structure was designed to anchor strings or bands that could facilitate the lifting or sideways folding of the liver creating sufficient workspace for the target upper abdominal procedures. The critical analysis of the project concluded a notable potential of the developed solution for achieving improved liver retraction with minimal tissue damage and minimal distraction of the surgeon from the main focus of the operation, which could be beneficial, in principle, even at robot-assisted procedures.

10. Incomplete cefuroxime penetration to the anterior and posterior column of the lumbar spine: an experimental porcine study

BACKGROUND CONTEXT Surgical site infection following spine surgery is associated with increased morbidity and mortality. Perioperative antibiotic prophylaxis is a key factor in lowering the risk of acquiring an infection. Previous studies have assessed perioperative cefuroxime concentrations in the anterior column of the cervical spine with an anterior surgical approach. However, the majority of surgeries are performed in the posterior column and many surgeries involve the lumbar spine. PURPOSE The objective of this study was to compare the perioperative tissue concentrations of cefuroxime in the anterior and posterior column during lumbar spine surgery with a posterior surgical approach. STUDY DESIGN/SETTING In vivo experimental pharmacokinetics study of cefuroxime concentrations in an acute preclinical porcine model. OUTCOME MEASURES The primary end-point was the time above cefuroxime clinical breakpoint minimal inhibitory concentration (T>MIC) for Staphylococcus aureus of 4 µg/mL. The secondary end-point was tissue penetration (AUCtissue/AUCplasma). METHODS The lumbar vertebral column was exposed from L1 to L5 in eight female pigs. Microdialysis catheters were placed for sampling in the anterior column (vertebral body) and posterior column (posterior arch) within the same vertebra (L5). Cefuroxime (1.5 g) was administered intravenously. Microdialysates and plasma samples were continously obtained over eight hours. Cefuroxime concentration were quantified by ultra high-performance liquid chromatography tandem mass spectrometry. RESULTS Mean T>MIC 4 µg/mL (95% confidence interval) was 123 min (105-141) in plasma, 97 min (79-115) in the anterior column and 93 min (75-111) in the posterior column. Tissue penetration (95% confidence interval) was incomplete for both the anterior column 0.48 (0.40-0.56) and posterior column 0.40 (0.33-0.48). CONCLUSIONS T>MIC was comparable between the anterior and posterior column. Mean cefuroxime concentrations decreased below the clinical breakpoint MIC for S. aureus of 4 µg/mL after 123 min (plasma), 97 min (anterior column) and 93 min (posterior column). Open lumbar spine surgery often involves extensive soft tissue dissection, stripping and retraction of the paraspinal muscles which may impair the local blood flow exposing the lumbar vertebra to postoperative infections. A single intravenous administration of 1.5 g cefuroxime only provided sufficient prophylactic target tissue concentrations in the vertebrae of the lumber spine for up to 1.5 hours. This is shorter than the duration of most lumbar spine surgeries, and therefore alternative dosing regimens should be considered in posterior open lumbar spine surgeries lasting more than 1.5 hours. FDA DEVICE/DRUG STATUS cefuroxime (Approved for this indication). Surgical site infection following spine surgery is associated with increased morbidity and mortality. Perioperative antibiotic prophylaxis is a key factor in lowering the risk of acquiring an infection. Previous studies have assessed perioperative cefuroxime concentrations in the anterior column of the cervical spine with an anterior surgical approach. However, the majority of surgeries are performed in the posterior column and many surgeries involve the lumbar spine. The objective of this study was to compare the perioperative tissue concentrations of cefuroxime in the anterior and posterior column during lumbar spine surgery with a posterior surgical approach. In vivo experimental pharmacokinetics study of cefuroxime concentrations in an acute preclinical porcine model. The primary end-point was the time above cefuroxime clinical breakpoint minimal inhibitory concentration (T>MIC) for Staphylococcus aureus of 4 µg/mL. The secondary end-point was tissue penetration (AUCtissue/AUCplasma). The lumbar vertebral column was exposed from L1 to L5 in eight female pigs. Microdialysis catheters were placed for sampling in the anterior column (vertebral body) and posterior column (posterior arch) within the same vertebra (L5). Cefuroxime (1.5 g) was administered intravenously. Microdialysates and plasma samples were continously obtained over eight hours. Cefuroxime concentration were quantified by ultra high-performance liquid chromatography tandem mass spectrometry. Mean T>MIC 4 µg/mL (95% confidence interval) was 123 min (105-141) in plasma, 97 min (79-115) in the anterior column and 93 min (75-111) in the posterior column. Tissue penetration (95% confidence interval) was incomplete for both the anterior column 0.48 (0.40-0.56) and posterior column 0.40 (0.33-0.48). T>MIC was comparable between the anterior and posterior column. Mean cefuroxime concentrations decreased below the clinical breakpoint MIC for S. aureus of 4 µg/mL after 123 min (plasma), 97 min (anterior column) and 93 min (posterior column). Open lumbar spine surgery often involves extensive soft tissue dissection, stripping and retraction of the paraspinal muscles which may impair the local blood flow exposing the lumbar vertebra to postoperative infections. A single intravenous administration of 1.5 g cefuroxime only provided sufficient prophylactic target tissue concentrations in the vertebrae of the lumber spine for up to 1.5 hours. This is shorter than the duration of most lumbar spine surgeries, and therefore alternative dosing regimens should be considered in posterior open lumbar spine surgeries lasting more than 1.5 hours.

Cefuroxime concentrations in the anterior and posterior column of the lumbar spine – an experimental porcine study

BACKGROUND CONTEXTSurgical site infection following spine surgery is associated with increased morbidity and mortality. Perioperative antibiotic prophylaxis is a key factor in lowering the risk of acquiring an infection. Previous studies have assessed perioperative cefuroxime concentrations in the anterior column of the cervical spine with an anterior surgical approach. However, the majority of surgeries are performed in the posterior column and many surgeries involve the lumbar spine. PURPOSEThe objective of this study was to compare the perioperative tissue concentrations of cefuroxime in the anterior and posterior column during lumbar spine surgery with a posterior surgical approach. STUDY DESIGNIn vivo experimental pharmacokinetic study of cefuroxime concentrations in an acute preclinical porcine model. METHODSThe lumbar vertebral column was exposed from L1 to L5 in 8 female pigs. Microdialysis catheters were placed for sampling in the anterior column (vertebral body) and posterior column (posterior arch) within the same vertebra (L5). Cefuroxime (1.5 g) was administered intravenously. Microdialysates and plasma samples were continuously obtained over 8 hours. Cefuroxime concentrations were quantified by Ultra High Performance Liquid Chromatography Tandem Mass Spectrometry. The primary endpoint was the time above the cefuroxime clinical breakpoint minimal inhibitory concentration (T>MIC) for Staphylococcus aureus of 4 µg/mL. The secondary endpoint was tissue penetration (AUCtissue/AUCplasma). RESULTSMean T>MIC 4 µg/mL (95% confidence interval) was 123 min (105–141) in plasma, 97 min (79–115) in the anterior column and 93 min (75–111) in the posterior column. Tissue penetration (95% confidence interval) was incomplete for both the anterior column 0.48 (0.40–0.56) and posterior column 0.40 (0.33–0.48). CONCLUSIONST>MIC was comparable between the anterior and posterior column. Mean cefuroxime concentrations decreased below the clinical breakpoint minimal inhibitory concentration for S. aureus of 4 µg/mL after 123 minutes (plasma), 97 minutes (anterior column) and 93 minutes (posterior column). This is shorter than the duration of most lumbar spine surgeries, and therefore alternative dosing regimens should be considered in posterior open lumbar spine surgeries lasting more than 1.5 hours. CLINICAL SIGNIFICANCEOpen lumbar spine surgery often involves extensive soft tissue dissection, stripping and retraction of the paraspinal muscles which may impair the local blood flow exposing the lumbar vertebra to postoperative infections. A single intravenous administration of 1.5 g cefuroxime only provided sufficient prophylactic target tissue concentrations in the vertebra of the lumbar spine for up to 1.5 hours.

P.165 Using artificial intelligence to quantify dynamic retraction of brain tissue and the manipulation of instruments in neurosurgery

Background: There is no objective way to measure the amount of manipulation and retraction of neural tissue by the surgeon. Our objective is to develop metrics quantifying dynamic retraction of cerebral tissue and the manipulation of instruments during a neurosurgical intervention. Methods: We trained a convolutional neural network to analyze microscopic footage of neurosurgical procedures and thereby generate metrics evaluating the surgeon’s dynamic retraction of brain tissue and the surgeon’s manipulation of the instruments themselves. U-Net image segmentation is used to output bounding polygons around cerebral parenchyma of interest, as well as the vascular structures and cranial nerves. Results: On the validation set, our network achieves a state of the art Intersection over Union (IoU) of 70.1% (Recall = 89%) and 74.3% (Recall = 91%) for surgical tools and biological structures respectively. Multivariate statistical analysis was used to evaluate dynamic retraction and tissue handling. Conclusions: We describe a semantic segmentation model for surgical instruments and intracranial structures to evaluate dynamic retraction of soft tissue and manipulation of instruments during a surgical procedure, while accounting for movement of the operative microscope. Using the intraoperative footage, this model can potentially provide the surgeon with objective feedback.