The pectus care guidelines: best practice consensus guidelines from the joint specialist societies SCTS/MF/CWIG/BOA/BAPS for the treatment of patients with pectus abnormalities.

Pectus defects are a group of congenital conditions found in approximately 1 in 250 people, where the sternum is depressed back towards the spine (excavatum), protrudes forwards (carinatum) or more rarely is a mixture of both (arcuatum or mixed defects). For the majority of patients, it is well tolerated, but some patients are affected psychologically, physiologically or both. The deformity becomes apparent at a young age due to the growth of the ribs and the cartilage that links them to the sternum. The majority of defects are mild and are well tolerated, i.e. they do not affect activity and do not cause psychological harm. However, some young people develop lower self-esteem and depression, causing them to withdraw from activities (such as swimming, dancing) and from interactions that might 'expose' them (such as sleepovers, dating, going to the beach and wearing fashionable clothes). This psychological harm occurs at a crucial time during their physical and social development. A small number of patients have more extreme depression of their sternum that impedes their physiological reserve, which can occur when engaging in strenuous exercise (such as running) but can also limit moderate activity such as walking and climbing stairs. The effects can be so extreme that symptoms occur at rest or cause life-threatening compression of the major blood vessels and organs. The group of patients with physiological impairment usually also suffer from low self-esteem and depression. This paper summarizes the current evidence for the different treatment strategies for this condition, including supportive care, psychological support and non-surgical techniques including bracing and vacuum bell therapy. We also consider surgical techniques including the Ravitch procedure, the Nuss procedure (minimally invasive repair of pectus excavatum), pectus implants and other rare procedures such as Pectus Up. For the majority of patients, supportive care is sufficient, but for a minority, a combination of the other techniques may be considered. This paper also outlines best practice guidance for the delivery of such therapies, including standardized assessment, consent to treatment, audit, quality assurance and long-term support. All the interventions have risks and benefits that the patient, parents and clinicians need to carefully consider and discuss when deciding on the most appropriate course. We hope this evidence review of 'Best Practice for Pectus' will make a significant contribution to those considerations and help all involved, from patients to national policy makers, to deliver the best possible care.

Pectus Disorders: Excavatum, Carinatum and Arcuatum.

This article reviews pectus excavatum, carinatum, and arcuatum. Topics covered include etiology, epidemiology, associated syndromes, physiologic impact, workup, indications for treatment, surgical and nonsurgical therapy, results, complications, and emerging therapies. Pectus excavatum is an inward deformation of the sternum and/or anterior chest wall. Pectus carinatum is ether an outward protrusion or tilt of the sternum with potential psychological impact, but no demonstrated physiologic impact. Nonoperative compression bracing is successful in carinatum patients with chest wall flexibility who are compliant with a bracing program. Pectus arcuatum is an abnormally short, fully fused sternum with a high anterior protrusion.

Intraventricular Thrombosis and Pulmonary Embolism Post-Nuss Procedure: A Rare Case of Chronic Bar Displacement in a 16-Year-Old Patient.

This novel report presents the first known case, to our knowledge, of a 16-year-old male patient who experienced intraventricular thrombosis and pulmonary embolism after a Nuss procedure for pectus excavatum, attributed to chronic bar displacement. Two years after the operation, the patient experienced post-exercise cough and hemoptysis, which led to his admission. Imaging revealed pulmonary embolism, thrombosis in the right ventricular outflow tract, and lung infiltrative lesions. We hypothesize that the chronic bar displacement led to its embedment in the right ventricle, resulting in thrombus formation, which subsequently contributed to partial pulmonary embolism. Surgery revealed the bars' intrusion into the right ventricle and lung. This case highlights the risk of severe complications from bar displacement in the Nuss procedure, which necessitates long-term follow-up evaluation, caution against strenuous activities after surgery, and use of thoracoscopic guidance during bar implantation and removal. It underscores the importance of vigilant evaluation for late-stage complications in patients with respiratory distress or thrombosis after a Nuss procedure.

Analgesic Effectiveness of Truncal Plane Blocks in Patients Undergoing the Nuss Procedure: A Randomized Controlled Trial.

INTRODUCTION: Most patients undergoing the Nuss procedure reported moderate to severe pain after surgery. This study aimed to investigate the efficacy and safety of ultrasound-guided serratus anterior plane block (SAPB) combined with transversus thoracic muscle plane (TTMP) block for relieving acute pain in patients undergoing the Nuss procedure. METHODS: The enrolled patients in our study were allocated to either receive combined nerve blocks with ropivacaine (NB group) or saline (CON group). The primary outcome of this study was postoperative pain at 2, 4, 8, 16, 24, 36, and 48 h during rest and movement (coughing). Secondary outcomes included intraoperative dosage of remifentanil, the time to extubation and the length of stay in the post-anesthesia care unit (PACU), the total acetaminophen and codeine tablet consumption, time to first bowel movement, time to first flatus, opioid-related adverse events, and the length of hospital stay. RESULTS: Patients in the NB group had significantly lower Numerical Rating Scale (NRS) pain scores compared with the CON group. The NB group required significantly less postoperative acetaminophen consumption and lower dosages of perioperative sufentanyl and remifentanil compared with the CON group. The length of stay in the PACU and time to extubation were significantly increased in the CON group compared with the NE group. Time to first bowel movement and time to first flatus were earlier in the NB group. But there were no significant differences between the groups in terms of the length of hospital stay and codeine tablet consumption. CONCLUSION: Ultrasound-guided SAPB and TTMP blocks in patients undergoing the Nuss procedure could provide effective analgesia. TRIAL REGISTRATION: This study was registered in the Chinese Clinical Trial Registry (ChiCTR2000038506).

Ultrasound-guided erector spinae plane block versus thoracic epidural block for postoperative analgesia in pediatric Nuss surgery: a randomized noninferiority trial.

PURPOSE: Thoracic epidural anesthesia (TEA) is often used for analgesia after thoracic surgery. Erector spinae plane block (ESPB) has been proposed to provide adequate analgesia. We hypothesized that ESPB would be noninferior to TEA as a part of multimodal analgesia in pediatric patients undergoing the Nuss procedure. METHODS: Patients aged 7-18 years and scheduled for the Nuss procedure were randomly allocated to receive bilateral single-shot ESPB or TEA and a multimodal analgesic regimen including parent-controlled intravenous analgesia (PCIA). At 6 h, 12 h, 18 h, and 24 h postoperatively, pain was evaluated using the numeric rating scale (NRS) and opioid consumption was assessed by counting the number of PCIA boluses. The joint primary outcomes were the average pain score and opioid consumption at 24 h after surgery. The secondary outcomes were the NRS scores and the number of opioid boluses administered at different postoperative time points, adverse events, and recovery quality. RESULTS: Three hundred patients underwent randomization, and 286 received ESPB (147 patients) or TEA (139 patients). At 24 h postoperatively, ESPB was noninferior to TEA in terms of the average NRS score (mean difference, - 0.1, 95% confidence interval [CI], - 0.3-0.1, margin = 1, P for noninferiority < 0.001) and the number of opioid boluses administered (mean difference, - 1.1, 95% CI, - 2.8-0.6, margin = 7, P for noninferiority < 0.001). Adverse events and patient recovery were comparable between groups. CONCLUSIONS: The results demonstrate that combined with a multimodal analgesia, ESPB provides noninferior analgesia compared to TEA with respect to pain score and opioid consumption among pediatric patients undergoing the Nuss procedure.

Polytherapy versus monotherapy in the treatment of tibial non-unions: a retrospective study.

BACKGROUND: Treating tibial non-unions efficiently presents a challenge for orthopaedic trauma surgeons. The established gold standard involves implanting autologous bone graft with adequate fixation, but the addition of biologicals according to the so-called diamond concept has become increasingly popular in the treatment of non-unions. Previous studies have indicated that polytherapy, which involves implanting mesenchymal stem cells, bioactive factors and osteoconductive scaffolds, can improve bone healing. This study aims to evaluate the efficacy of polytherapy compared with monotherapy in treating tibial non-unions of varying severity. MATERIALS AND METHODS: Data from consecutive tibial non-unions treated between November 2014 and July 2023 were retrospectively analysed. The Non Union Scoring System (NUSS) score before non-union surgery, and the Radiographic Union Score for Tibial fractures (RUST), scored at 1, 3, 6, 9, 12 and 18 months post-surgery, were recorded. Initially, a comparison was made between the polytherapy and monotherapy groups. Subsequently, patients receiving additional surgical non-union treatment were documented, and the frequency of these treatments was tallied for a subsequent per-treatment analysis. RESULTS: A total of 34 patients were included and divided into a polytherapy group (n = 15) and a monotherapy group (n = 19). The polytherapy group demonstrated a higher NUSS score (44 (39, 52) versus 32 (29, 43), P = 0.019, z = -2.347) and a tendency towards a higher success rate (93% versus 68%, P = 0.104) compared with the monotherapy group. For the per-treatment analysis, 44 treatments were divided into the polytherapy per-treatment group (n = 20) and the monotherapy per-treatment group (n = 24). The polytherapy per-treatment group exhibited a higher NUSS score (48 (43, 60) versus 38 (30, 50), P = 0.030, z = -2.173) and a higher success rate (95% versus 58%, P = 0.006) than the monotherapy per-treatment group. Within the monotherapy per-treatment group, the NUSS score displayed excellent predictive performance (AUC = 0.9143). Setting the threshold value at 48, the sensitivity and specificity were 100.0% and 70.0%, respectively. CONCLUSIONS: Polytherapy is more effective than monotherapy for severe tibial non-unions, offering a higher success ratio. The NUSS score supports decision-making in treating tibial non-unions. LEVEL OF EVIDENCE: Level III.

Does a high Haller index influence outcomes in pectus excavatum repair?

OBJECTIVE: Severity for pectus excavatum includes Haller index (HI) > 3.25. An extremely high HI (≥8) may influence surgical approach and complications. This study reviews outcomes of patients with high HI after repair. METHODS: A single institution retrospective analysis was performed on adult patients with HI ≥ 8 undergoing pectus excavatum repairs. For outcomes, a propensity score-matched control group with a HI ≤ 4 was utilized. RESULTS: In total, 64 cases (mean age, 33.5 ± 10.9 years; HI, 13.1 ± 5.0; 56% women) were included. A minimally invasive repair was successful in 84%. A hybrid procedure was performed in the remaining either to repair fractures of the ribs (8 patients) and sternum (5 patients) or when osteotomy and/or cartilage resection was required (10 patients). In comparison with the matched cohort (HI ≤ 4), patients with high HI had longer operative times (171 vs 133 minutes; P < .001), more frequently required hybrid procedures (16% vs 2%; P = .005), experienced higher incidences of rib (22% vs 3%; P = .001) and sternal fractures (12% vs 0%; P = .003), and had increased repair with 3 bars (50% vs 19%; P < .001). There were no significant differences between the groups for length of hospital stay or postoperative 30-day complications. CONCLUSIONS: Patients with an extremely high HI can be challenging cases with greater risks of fracture and need for osteotomy/cartilage resection. Despite this, minimally invasive repair techniques can be utilized in most cases without increased complications when performed by an experienced surgeon.

Biocompatible Cable Ties Are an Alternative to Metal Stabilizers for Bar Securement During Minimally Invasive Pectus Excavatum Repair.

Background: Bar stabilization during minimally invasive pectus excavatum repair (MIRPE) is critical to avoid dislodgement. Multiple techniques are described including stabilizers, wires, and sutures. This retrospective study compared bar movement and outcomes between existing techniques and ZipFix™, a biocompatible cable tie. Methods: Patients ≤20 years of age who underwent MIRPE with ZipFix between January 2021 and September 2022 were compared with historical controls who underwent repair by same surgeons between January 2018 and December 2020 using stabilizers or polydioxanone suture (PDS). Demographics, clinical details, and outcomes were compared using Kruskal-Wallis and chi-square tests. Results: Of the 116 patients who underwent repair, 45 had bars secured with ZipFix (39%) and 71 (61%) were historical controls (35 stabilizer, 36 PDS). Median (interquartile range) age was 15 (14-16) years and Haller index was 3.9 (3.6-4.5). Nine (8%) patients required two bars. Haller index and use of second bar were comparable between stabilization techniques (P > .05). In total, 49 patients (40%) reported any pain at 1 month and this was similar between stabilization techniques (P = .45). Median bar movement was greater for bars secured with PDS than with ZipFix or stabilizers at 1 month (5.5 versus 2.3 versus 3.3°, P = .010) and last follow-up (6.5 versus 2.1 versus 3.6°, P < .001). One patient whose bar was secured with PDS required revision for dislodgement. Conclusion: Pectus bar stabilization with ZipFix is a safe alternative to metal stabilizers and both techniques are superior to suture stabilization alone. The use of ZipFix may be preferred given its lower cost and ease of use.

Pectus excavatum. Surgical treatment: Structural or aesthetic?

INTRODUCTION: Pectus excavatum is a wall deformity that often warrants medical evaluation. In most cases, it's a purely visual aesthetic alteration, while in others, it comes with symptoms. Several surgical techniques have been described, but their outcomes are difficult to assess due to the heterogeneity of presentations and the lack of long-term follow-up. We present our experience as thoracic surgeons, assessing correction as either structural (remodeling of the thoracic cage through open surgery) or aesthetic (design and implantation of a customized 3D prosthesis). MATERIAL AND METHODS: Retrospective observational study of the indication for surgical treatment of pectus excavatum carried out by a team of thoracic surgeons and the short- to mid-term results. RESULTS: Between 2021 and 2023, we treated 36 cases surgically, either through thoracic cage remodeling techniques or with 3D prostheses. There were few minor complications, and the short- to mid-term results were positive: alleviation of symptoms or compression of structures when present, or aesthetic correction of the defect in other cases. CONCLUSIONS: Surgery for pectus excavatum should be evaluated for structural correction of the wall or aesthetics. In the former, thoracic cage remodeling requiring cartilage excision and possibly osteotomies is necessary. In the latter, the defect is corrected with a customized 3D prosthesis.

Impact of delayed removal of pectus bar on outcomes following Nuss repair: a retrospective analysis.

BACKGROUND: Usually, pectus bars are removed 3 years after the Nuss procedure in patients with pectus excavatum. However, the optimal timing for postoperative pectus bar removal remains undefined. Our study investigated the effects of delayed pectus bar removal after Nuss repairs. METHODS: Retrospective data were collected on patients who underwent Nuss procedures for pectus excavatum and had their bars removed from August 2014 to December 2020. Patients with correction periods > 3 years were divided into group A (< 6 years) and group B (≥ 6 years). Propensity score matching was used to compare complications and radiological outcomes associated with bar removal. RESULTS: Of the 542 patients who underwent bar removal, 451 (Group A: 419 patients, Group B: 32) had correction duration > 3 years. The average correction duration was 4.5 ± 1.4 years. After propensity score matching analysis, group B [median duration: 8.0 (6.0-16.2) years] exhibited significantly longer median operative times (85 vs. 55 min; P = 0.026), higher callus formation rates (68.8% vs. 46.9%; P = 0.029), and greater median intraoperative blood loss (35 vs. 10 mL; P = 0.017) than group A [median duration: 4.2 (3.0-5.9) years]. However, following bar removal, the groups showed no statistical differences in the surgical complication rates (group A: 6.3% vs. group B: 9.4%; P = 0.648) or median ratio of radiological improvement (an improvement on the Haller index on chest radiography; 21.0% vs. 22.2%; P = 0.308). CONCLUSIONS: Delaying pectus bar removal after Nuss repair presents certain challenges but does not compromise overall outcomes. These findings suggest that a longer correction period may be unnecessary. However, further multicenter studies with long-term follow-up are warranted to assess long-term outcomes.

S-ICD Implantation in Secondary Prevention in a Young Patient With Recent Surgically Repaired Pectus Excavatum.

We report a case of successful implantation of a subcutaneous implantable cardioverter-defibrillator in a young patient with severe pectus excavatum presenting with out-of-hospital ventricular fibrillation arrest who was recently surgically repaired with a MIRPE-Nuss procedure. No complications in lead positioning were observed, and the device was tested to determine that it functioned properly.

Body measurement changes in adults with pectus excavatum after the Nuss procedure: a study of 272 patients.

BACKGROUND: Pectus excavatum (PE) is the most common congenital abnormality of the chest wall. Most patients with PE have slim bodies. Some studies have been conducted on the physical growth of children and adolescents who underwent the Nuss procedure. This study aimed to evaluate body measurement changes in adult patients with PE after the Nuss procedure. METHODS: A total of 272 adult PE patients, who underwent the Nuss procedure and pectus bars removal from August 2014 to December 2020, were evaluated retrospectively. Body measurement [body height (BH), body weight (BW), and body mass index (BMI)] of the patients were collected before Nuss repair and after bar removal. We used the interquartile range (IQR) to identify and exclude outliers. Associations between changes in body measurement and clinical and radiological features were evaluated. RESULTS: The BH, BW and BMI showed significantly increased after pectus bar removal, compared to pre-Nuss procedure parameters (BH 173.8 ± 5.9 cm vs. 173.9 ± 5.9 cm, P < 0.001; BW 60.3 ± 8.1 kg vs. 61.1 ± 8.8 kg, P = 0.005; BMI 19.9 ± 2.2 kg/m2 vs. 20.1 ± 2.4 kg/m2, P = 0.02). The same result were observed in the male subgroup, the HI ≥ 4 group and the male subgroup within the HI ≥ 4 group. CONCLUSIONS: The BH, BW and BMI were significantly increased after completing surgical correction of PE using the Nuss procedure, particularly in young males and patients with more pronounced deformities.

Biomechanical Effectivity Evaluation of Single- and Double-Metal-Bar Methods with Rotation and Equilibrium Displacements in Nuss Procedure Simulations.

Surgical treatment of the pectus excavatum has led to the introduction of the Nuss procedure, a minimally invasive surgical procedure that involves inserting a metal bar under the sternum through a small lateral thoracic incision. An additional metal bar was inserted in patients with pectus excavatum to improve the retention of the restored chest wall after the Nuss procedure. However, a need still exists to analyze the mechanistic advantages and disadvantages of the double-bar method owing to the increased surgical time and proficiency. The purpose of this study is to compare and evaluate the efficiency of single- and double-bar methods using rotational and equilibrium displacement simulations of the Nuss procedure. A finite-element model was constructed for two types of metal bars inserted into the chest wall. Boundary conditions for the rotation and equilibrium displacements were set for the metal bar. The anterior sternal translation, Haller index and maximum equivalent stress and strain owing to the behavior of the metal bar were estimated and compared with the single-bar method and postoperatively acquired patient data. The simulation results showed that the influences of the intercostal muscle and equilibrium after rotation displacement were significant. The stresses and strains were distributed across the two metal bars, and the upper-metal bar was heavily loaded. The double-bar method was advantageous regarding the load distribution effects of the two metal bars on the chest wall. However, mechanical assessments are also important because an excessive load is typically applied to the upper-metal bar.

Outcomes After Pectus Excavatum Repair: Center Volume Matters.

PURPOSE: Pectus excavatum (Pectus) repair may be offered for those with significant cardiopulmonary compromise or severe cosmetic defects. The influence of hospital center volume on postoperative outcomes in children is unknown. This study aimed to investigate the outcomes of children undergoing Pectus repair, stratified by hospital surgical volume. METHODS: The Nationwide Readmission Database was queried (2016-2020) for patients with Pectus (Q67.6). Patients were stratified into those who received repair at high-volume centers (HVCs; ≥20 repairs annually) versus low-volume centers (LVCs; <20 repairs annually). Demographics and outcomes were analyzed using standard statistical tests. RESULTS: A total of 9414 patients with Pectus underwent repair during the study period, with 69% treated at HVCs and 31% at LVCs. Patients at LVCs experienced higher rates of complications during index admission, including pneumothorax (23% vs. 15%), chest tube placement (5% vs. 2%), and overall perioperative complications (28% vs. 24%) compared to those treated at HVCs, all p < 0.001. Patients treated at LVCs had higher readmission rates within 30 days (3.8% vs. 2.8% HVCs) and overall readmission (6.8% vs. 4.7% HVCs), both p < 0.010. Among readmitted patients (n = 547), the most frequent complications during readmission for those initially treated at LVCs included pneumothorax/hemothorax (21% vs. 8%), bar dislodgment (21% vs. 12%), and electrolyte disorders (15% vs. 9%) compared to those treated at HVCs. CONCLUSION: Pediatric Pectus repair performed at high-volume centers was associated with fewer index complications and readmissions compared to lower-volume centers. Patients and surgeons should consider this hospital volume-outcome relationship. TYPE OF STUDY: Retrospective Comparative. LEVEL OF EVIDENCE: III.

Presence of manubrium-sternum joint does not assure sufficient elevation of sternum in Nuss procedure for pectus excavatum patients.

BACKGROUND: The manubrium and body of the sternum are connected by the manubrium-sternum joint (MSJ). In performing the Nuss procedure for pectus excavatum patients, the body of the sternum is elevated as the operator flips correction bars upside down. Theoretically, the presence of the MSJ should allow elevation of the sternum body. However, does the MSJ secure sufficient elevation of the sternum? This study aims to elucidate this clinical question. METHODS: Seventy-four adult pectus excavatum patients with moderate to serious deformity (with Haller Index being equal to or greater than 5) were included in the study. The MSJ was open in all patients. For 29 patients, the sternum was elevated by only bar flipping (Non-Separation Group); for 45 patients, the sternum was horizontally separated after bar flipping (Separation Group). Whether or not additional elevation for Separation Group patients results from the division was observed, and the degree of the additional elevation was evaluated. Furthermore, 74 patients subjectively evaluated postoperative pain and gave scores with a Visual Analog Scale ranging from 0 (no pain) to 10 (intolerable pain). The VAS scores were compared between the two groups. RESULTS: In the Separation Group, the sternums of all patients achieved additional elevation from sternum separation. The pain scores were lower for the Separation Group than for the Non-Separation Group. CONCLUSION: Even when the MSJ is present, horizontal separation enhances the elevation of the sternum. Furthermore, horizontal separation of the sternum reduces postoperative pain.

Intercostal spinal nerve cryoablation for analgesia following pectus excavatum repair.

Pectus excavatum is a common chest wall deformity, most often treated during adolescence, that presents a significant postoperative pain control challenge for pediatric surgeons following surgical correction. The purpose of this article is to review the technique and outcomes of intercostal spinal nerve cryoablation for postoperative analgesia following surgical correction of pectus excavatum. Contemporary and historic literature were reviewed. Findings are summarized to provide a concise synopsis of the benefits of intercostal spinal nerve cryoablation relative to alternative analgesic modalities, as well as advocate for more widespread inclusion of this technique into multimodal pain regimens.

Lessons Learned after 176 Patients Treated with a Standardized Procedure of Thoracoscopic Cryoanalgesia during Minimally Invasive Repair of Pectus Excavatum.

BACKGROUND: Intrathoracic intercostal cryoanalgesia (Cryo) during minimally invasive repair of pectus excavatum (MIRPE) reports have been related to improved pain management, although its extent differs amongst studies. We aimed to report our experience using a standardized perioperative approach including Cryo during MIRPE, and compare our actual results with those of a previous thoracic epidural analgesia (TE) cohort. Lessons learned are summarized. METHODS: Retrospective study including patients undergoing Cryo during MIRPE between October 2018 and May 2023. Results with a standardized perioperative approach were analyzed. We then compared our Cryo cohort with a previous cohort of 62 patients who underwent TE and MIRPE between 2013 and 2018. Continuous variables were reported as mean and standard deviation, and as median (interquartile range) for variables with non-uniform distribution. RESULTS: We performed 176 Cryo during MIRPE (16.8 ± 4.6 years), with a mean postoperative length of stay (LOS) of 1.4 ± 0.8 days and a median total requirement of 7.5 (0.0; 15.0) oral morphine equivalents (OME) (mg). Patients with Cryo had a significantly lower mean LOS (1.4 ± 0.8 vs. 3.6 ± 1.0 days, p < 0.0001), and median total opioid requirement [7.5 (0.0; 15.0) vs. 77.4 (27.0; 115.5 OME (mg), p < 0.0001) compared to TE patients. Lessons learned included ensuring adequate contact of the cryoprobe with the target, proper exposition, and specialized multidisciplinary perioperative patient and family support, including psychology and physical therapy. CONCLUSIONS: In this study, we reported lessons learned after performing a standardized protocol of perioperative care in patients undergoing Cryo during MIRPE. This protocol enabled the achievement of a short LOS and low postoperative opioid requirement. TYPE OF STUDY: Retrospective comparative study. LEVEL OF EVIDENCE: III.

The electrocardiographic manifestations of pectus excavatum before and after surgical correction.

BACKGROUND: Pectus excavatum (PEx) can cause cardiopulmonary limitations due to cardiac compression and displacement. There is limited data on electrocardiogram (ECG) alterations before and after PEx surgical repair, and ECG findings suggesting cardiopulmonary limitations have not been reported. The aim of this study is to explore ECG manifestations of PEx before and after surgery including associations with exercise capacity. METHODS: A retrospective review of PEx patients who underwent primary repair was performed. ECGs before and after surgical correction were evaluated and the associations between preoperative ECG abnormalities and cardiopulmonary function were investigated. RESULTS: In total, 310 patients were included (mean age 35.1 ± 11.6 years). Preoperative ECG findings included a predominant negative P wave morphology in V1, and this abnormal pattern significantly decreased from 86.9% to 57.4% (p < 0.001) postoperatively. The presence of abnormal P wave amplitude in lead II (>2.5 mm) significantly decreased from 7.1% to 1.6% postoperatively (p < 0.001). Right bundle branch block (RBBB) (9.4% versus 3.9%, p < 0.001), rsr' patterns (40.6% versus 12.9%, p < 0.001), and T wave inversion in leads V1-V3 (62.3% vs 37.7%, p < 0.001) were observed less frequently after surgery. Preoperative presence of RBBB (OR = 4.8; 95%CI 1.1-21.6) and T wave inversion in leads V1-3 (OR = 2.3; 95%CI 1.3-4.2) were associated with abnormal results in cardiopulmonary exercise testings. CONCLUSION: Electrocardiographic abnormalities in PEx are frequent and can revert to normal following surgery. Preoperative RBBB and T wave inversion in leads V1-3 suggested a reduction in exercise capacity, serving as a marker for the need for further cardiovascular evaluation of these patients.

Preoperative Metal Allergy Testing for Pectus Excavatum Repair Does Not Effectively Identify Patients Who Develop Metal bar Allergy.

BACKGROUND: Metal allergy following placement of a metal pectus bar for minimally invasive repair of pectus excavatum (MIRPE) is a rare complication with potentially significant morbidity. There is no consensus regarding preoperative metal allergy testing (MAT). This study aims to assess incidence of metal allergy and titanium bar use in tested and untested patients and trends in MAT with different approaches to MAT. METHODS: A retrospective chart review was performed on patients who underwent MIRPE from July 2009 to June 2022 at a single institution. During this time, MAT was performed routinely (RT; routine testing) and selectively (ST; selective testing). RESULTS: The cohort included 741 patients for analysis. Metal bar allergy was documented in 1.3 % of all patients; the incidence was 1.3 % in patients with MAT and 1.4 % without MAT. The incidence of bar allergy was 1.1 % in the RT group and 1.6 % in the ST group. In the RT group, bar allergy occurred in 1.4 % (3/216) of patients with a negative MAT. In the ST group, bar allergy occurred in 1.2 % (2/164) of patients with a negative MAT and in 1.9 % (3/162) of untested patients with a stainless-steel bar. Titanium bar use was not significantly different between the RT and ST groups (18.3 % vs 16.3 %, p > 0.05). CONCLUSION: The incidence of metal bar allergy after MIRPE was less than 2 %, and titanium bar use was not significantly different in routine and selective testing groups. MAT was not associated with a reduction in bar allergy, and its use remains unsupported. LEVEL OF EVIDENCE: III.

Biomechanical Evaluation of Additional Surgical Maneuvers to Improve Symmetry in Performing Nuss Procedure for Asymmetric Pectus Excavatum.

Background: Severing part of the thorax prior to bar placement is effective to improve outcomes in performing the Nuss procedure for asymmetric pectus excavatum. This study aims to elucidate the patterns of severing to provide an ideal outcome. Methods: Three-dimensional biomechanical computer models were produced simulating the thoraxes of 10 actual patients with asymmetric pectus excavatum. Virtual surgical operation was performed on the 10 models in 4 patterns: group 1-no part of the thorax was severed (default group). Group 2-The sternum was severed (sternum-severing group). Group 3-The ribs on the affected side were severed (rib-severing group). Group 4-Both the sternum and ribs on the affected side were severed (sternum/rib-severing group). After performing this preparation, simulation of bar placement was performed. Comparing the pre- and postoperative shapes of the models, we examined whether symmetry improved for each group. Results: Symmetry of the chest wall improved for rib-severing group and sternum/rib-severing group. Asymmetry remained for default group and sternum-severing group. Conclusions: Performance of the Nuss procedure for asymmetric pectus excavatum does not greatly improve symmetry of the chest wall. Severing the ribs as an additional maneuver is effective to improve symmetry.