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.

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.

Machine Learning: Using Xception, a Deep Convolutional Neural Network Architecture, to Implement Pectus Excavatum Diagnostic Tool from Frontal-View Chest X-rays.

Pectus excavatum (PE), a chest-wall deformity that can compromise cardiopulmonary function, cannot be detected by a radiologist through frontal chest radiography without a lateral view or chest computed tomography. This study aims to train a convolutional neural network (CNN), a deep learning architecture with powerful image processing ability, for PE screening through frontal chest radiography, which is the most common imaging test in current hospital practice. Posteroanterior-view chest images of PE and normal patients were collected from our hospital to build the database. Among them, 80% were used as the training set used to train the established CNN algorithm, Xception, whereas the remaining 20% were a test set for model performance evaluation. The performance of our diagnostic artificial intelligence model ranged between 0.976-1 under the receiver operating characteristic curve. The test accuracy of the model reached 0.989, and the sensitivity and specificity were 96.66 and 96.64, respectively. Our study is the first to prove that a CNN can be trained as a diagnostic tool for PE using frontal chest X-rays, which is not possible by the human eye. It offers a convenient way to screen potential candidates for the surgical repair of PE, primarily using available image examinations.

A retrospective study on the impact of bar flipping on the recurrence of pectus excavatum after the Nuss procedure.

BACKGROUND: The Nuss procedure is widely used to correct pectus excavatum. Bar displacement is a common complication associated with this procedure. How the flipping of the bar affects pectus excavatum recurrence has not been reported. In our study, we discuss this and also offer an easier method to determine bar flipping. METHODS: This retrospective study analyzed pectus excavatum patients who underwent primary Nuss repair from August 2014 to December 2018. The preoperative and postoperative Haller indices were measured on chest radiographs (cxrHI). The slope angle of bar flipping (α) was measured on lateral chest radiographs. The improvement index after surgical repair was calculated by: ([preoperative cxrHI-postoperative cxrHI]/preoperative cxrHI × 100). The impact of α on the improvement index was analyzed using one-way analysis of variance and receiver operating characteristic tests. RESULTS: In this study, 359 adult and adolescent patients with an average age of 23.9 ± 7.7 years were included. We formed four subgroups based on the α value: α ≤ 10° (n = 131), α = 11-20° (n = 154), α = 21-30° (n = 51), and α > 30° (n = 23). The mean improvement indices in these groups were 27%, 28%, 26%, and 13%, respectively. Patients with α > 30° were associated with a significantly poorer improvement index than those from the other subgroups (p < 0.001). CONCLUSIONS: The α value is an alternative measurement method for presenting the radiological outcomes after the Nuss procedure. An α > 30° indicates a possible recurrence of pectus excavatum after the Nuss repair. Surgical revision may be considered in patients with an α > 30°, while monitoring should be considered in the other patient groups.