Early thrombus detection in the extracorporeal membrane oxygenation circuit by noninvasive real-time ultrasonic sensors.

Thrombus formation in extracorporeal membrane oxygenation (ECMO) remains a major concern as it can lead to fatal outcomes. To the best of our knowledge, there is no standard non-invasive method for quantitatively measuring thrombi. This study's purpose was to verify thrombus detection in an ECMO circuit using novel, non-invasive ultrasonic sensors in real-time, utilizing the fact that the ultrasonic velocity in a thrombus is known to be higher than that in the blood. Ultrasonic sensors with a customized chamber, an ultrasonic pulse-receiver, and a digital storage oscilloscope (DSO) were used to set up the measuring unit. The customized chamber was connected to an ECMO circuit primed with porcine blood. Thrombi formed from static porcine blood were placed in the circuit and ultrasonic signals were extracted from the oscilloscope at various ECMO flow rates of 1-4 L/min. The ultrasonic signal changes were successfully detected at each flow rate on the DSO. The ultrasonic pulse signal shifted leftward when a thrombus passed between the two ultrasonic sensors and was easily detected on the DSO screen. This novel real-time non-invasive thrombus detection method may enable the early detection of floating thrombi in the ECMO system and early management of ECMO thrombi.

Recent Advancements in Pectus Surgery: Crane Lifting, Multiple-Bar Approach, Bridge Stabilization, and Sandwich Technique.

PURPOSE: The most recent procedure for pectus excavatum repair involves crane-powered entire chest wall remodeling, which employs crane lifting, multiple-bar approach, bridge stabilization, and sandwich techniques. This resulted in a paradigm shift in pectus deformity repair from merely lifting the sunken bone to remodeling the chest wall into normal anatomy. METHODS: We analyzed 649 patients who underwent surgery for pectus excavatum or complex combined deformities between March 2018 and January 2022. A crane with sternal wiring or screwing was used to lift the chest wall without using the pectus bar turning power. Multiple bars with bridge connections were placed to eliminate bar displacement. Modified sandwich techniques were applied to relieve the lower coastal flare (flare-buster) and focal protuberance (magic string). RESULTS: The mean age of the patients included in the study was 12.2 years (range: 3-45 years). A single bar was used for 202 patients until 2021. For the multiple-bar technique, parallel bars (n = 142), crossbars (n = 166), and crossbars plus upper horizontal bars (XI pattern; n = 139) were used. The overall complication rate was 6.2 %. There was no cases of bar displacement were observed, but other minor complications such as pneumothorax (n = 20, 3.1 %), pleural effusion (n = 7, 1.1 %), and wound infection (n = 5, 0.8 %) were detected. Three patients required reoperation (infection, two: hemorrhage, one). CONCLUSIONS: The crane-powered entire chest wall remodeling technique improved the safety and comprehensiveness of the repair procedure. By incorporating bridge stabilization and the use of multiple bars, we effectively resolved the issues related to bar displacement and incomplete repair. TYPE OF STUDY: Retrospective Cohort Study.

Technical Advances in Pectus Bar Stabilization in Chest Wall Deformity Surgery: 10-Year Trends and an Appraisal with 1,500 Patients.

Background: We aimed to demonstrate the advances we have achieved in pectus excavatum surgery over the last 10 years, with a particular focus on the refinement of pectus bar stabilization techniques and devices. Methods: In total, 1,526 patients who underwent minimally invasive repair of pectus excavatum surgery from 2013 to 2022 were enrolled and analyzed. We have pursued a new paradigm of crane-powered remodeling of the entire chest wall. The method of bar stabilization has changed from claw fixators to hinge plates and, finally, to bridge plate connections. We also evaluated the effectiveness of the hinge plate (group H) and the bridge plate (group B). Results: The bar displacement rates were 0.1% (n=2) for the claw fixator, 0% for the hinge plate (n=0), and 0% for the bridge plate (n=0). We stopped using the claw fixator in 2022 and the hinge plate in 2019. Since 2022, when we shifted to a multiple-bar technique for all patients, the bridge plate has replaced both the claw fixator and the hinge plate. No bar displacement occurred in either group. Group H had more pleural effusion, wound problems (p<0.05), and longer stays (5.5 vs. 6.2 days, p=0.034) than group B. Conclusion: We have made significant progress in pectus repair surgery over the last decade, particularly in stabilizing the pectus bar and reducing perioperative complications. Our current strategy is the multiple-bar approach with bridge stabilization. Since the bridge-only technique resulted in no bar displacement, we could eliminate the invasive claw fixator or hinge plate.

Crane-powered pectus excavatum repair: the NeoPectus surgery.

Introduction: The conventional technique for pectus excavatum repair was pushing up the depressed chest wall by turning over the convexity of the bent pectus bar. We developed a new concept in which a total crane lift was used as the source of power to elevate the depressed sternum without using pectus bar leverage. This study aims to verify the efficacy of exclusively crane-powered pectus excavatum repair in recent years. Methods: Among the 3622 pectus deformity repairs since 1999, 691 cases repaired with the total crane power between 2017 and 2022 were enrolled. The mean age was 12.0 years (3-45). The operative technique involved wire/screw crane elevation of the sternum, the entire chest wall remodeling with the cross or parallel bars, the bridge/claw bar fixations, and other adjunctive techniques. Outcome analysis included morphological variations, patterns of pectus bar placement, and complication rates. Results: The crane technique and pectoscopy (100%) were used. The bar placements were parallel (22.0%) and cross-bar (47.5%). The bar fixations were the claw fixators for a single bar (30.5%) and the bridge plates for multiple bars (69.5%). The flare-buster and magic strings were liberally used. No serious complications or catastrophic events occurred, but minor complications occurred in 16.9%: pneumothorax in 7.4% (51), pleural effusion in 1.6% (11), and wound problems in 0.4% (3). There was no case of bar displacement. Discussion: The crane-powered pectus excavatum repair showed excellent results with minimal complications and no bar displacement. This innovative approach, part of the NeoPectus surgery, represents a significant advancement in correcting pectus excavatum deformities by utilizing a crane machine to elevate the chest wall.

Serratus anterior plane block for acute pain management after pectus excavatum repair.

Introduction: Conventional postoperative pain management using an intravenous (IV) patient-controlled approach or thoracic epidural analgesia is suboptimal following minimally invasive repair of the pectus excavatum (MIRPE). Recently, cryoanalgesia has gained popularity owing to its superior pain control outcomes compared to those associated with conventional methods. However, because of its invasiveness, additional instrumentation requirement, and limited effect at early postoperative periods, we hypothesized that serratus anterior plane block (SAPB) could be an effective method for post-repair pain management and a possibly superior alternative. Methods: We conducted a retrospective cohort study of pediatric patients who had undergone MIRPE between March 2022 and August 2023. We compared the efficacy of pain control in three groups among 74 patients: Group N (conventional pain management, n = 24), Group C (cryoanalgesia, n = 24), and Group S (SAPB, n = 26). Group N received IV patient-controlled analgesia (PCA) and a subcutaneous local anesthetic infusion. Group C received bilateral cryoanalgesia on the fourth and seventh intercostal nerves using a cryoprobe at -80°C for 2 min during the operation and IV-PCA postoperatively. Group S received continuous bilateral SAPB with 0.25% ropivacaine and IV-PCA. The pain levels were measured using the visual analog scale (VAS; resting and dynamic), and the total IV rescue analgesic consumption was determined. Results: The three groups had similar baseline characteristics. Group S showed significantly less pain throughout the immediate postoperative course, resting VAS score at 3 h (Group N, 7.21 vs. Group C, 5.75 vs. Group S, 3.81; p < 0.001), and prominent less total IV rescue analgesic consumption (Group N, 116.16 mg vs. Group C, 52.75 mg vs. Group S, 16.61 mg; p < 0.001). Conclusion: SAPB resulted in better postoperative pain control than that associated with cryoanalgesia and conventional pain management after pectus excavatum repair, As it was effective in the immediate postoperative period, achieving a VAS score of <4 points (moderate pain) at 3 h postoperatively, it may play an important role and replace invasive cryoanalgesia in the management of pain after pectus surgery.

Repair of Recurrent Pectus Excavatum with a Huge Chest Wall Defect in a Patient with a Previous Ravitch and Pectus Bar Repair: A Case Report.

Recurrent pectus excavatum (PE) after a Ravitch operation is not uncommon. Extensive costal cartilage resection from the previous Ravitch procedure can lead to an irregular, unstable chest wall depressions with a varying degree of deformity. The optimal approach to cover the chest wall defect and remodel the deformity, remains unknown. We report the case of a 27-year-old woman seeking surgery for the third time for recurrent PE. The patient presented with 2-time recurrent pectus excavatum following a failed Ravitch procedure and subsequent pectus bar repair. The entire chest wall reconstruction and remodeling entailed covering the chest wall defect with 2 titanium plates across both sides of the rib cage, and lifting and fixing the depressed chest wall with 2 parallel pectus bars.

Development of a Screw-Crane System for Pre-Lifting the Sternal Depression in Pectus Excavatum Repair: A Test of Mechanical Properties for the Feasibility of a New Concept.

BACKGROUND: Pre-lifting of the sternum marked a major turning point in pectus excavatum repair. The author developed the crane technique in 2002 and successfully applied it to more than 2,000 cases using sternal wire stitching. However, blind sternal suturing limited the use of the wire-stitch crane. We propose a novel screw for sternal lifting as a new tool for the crane technique. METHODS: We developed a screw system strong enough to withstand the pressure needed for sternum lifting. The screw was designed to have a broader thread to hold the bony tissue securely. The screw's sustaining power was tested using the torsion, driving torque, and axial pull-out tests in a polyurethane block and ex-vivo porcine sternum. RESULTS: The screws were easily driven into the sternum, and the head of the screw was connectable to the table-mounted retractor. In the torsion test, the 2° offset torsional yield was 4.53 N·m (reference value, 1 N·m). In the polyurethane block driving torque test, the maximum torque was 0.98 N·m (reference value, 0.70 N·m). The axial pull-out test was 446 N (reference value, 100 N). The maximum pull-out resistance in the ex-vivo porcine sternum model was 1,516 N. CONCLUSION: The screw crane was strong enough to sustain the chest wall weight to be lifted. Thus, the screws could effectively replace the sternal wire stitching in crane pre-lifting of the sternum. We expect that application of the screw-crane will be easy and that it will improve the safety and success rate of pectus repair surgery.