Evaluation of Chest Wall Motility After MIRPE

Chest Wall Motility in Pectus Excavatum Patients Before and After MIRPE Performed With One or Two Metallic Bars: a Comparative Study

Pectus excavatum (PE) is the most common congenital deformity of the chest wall and surgical treatment using the minimally invasive technique (MIRPE) is consolidating as the choice to perform PE correction. In this technique, a temporary metal bar is placed in a retrosternal position, pushing the sternum without the need for cartilage resection. Despite the advantages obtained, it is not free from complications, with the displacement of the bar being one of the main problems. Therefore, the aim of this study is to evaluate a new bridging device for the set of two metal bars to be used in the surgical treatment of PE, verifying the clinical and surgical complications and evaluating the change in lung volumes and thoracoabdominal kinematics using optoelectronic plethysmography , preoperatively and 180 days after MIRPE; and also evaluating diaphragmatic mobility via ultrasound examination to assess the craniocaudal displacement of the left branch of the vein preoperatively and 180 days later. There will be 20 participants, who after performing a computed tomography of the chest to obtain the Haller index, clinical and laboratory tests, electrocardiogram and echocardiogram. Participants will be randomized and divided into two groups: 10 control individuals (traditional MIRPE technique used in the Service) and 10 intervention individuals (with bridge fixators developed in partnership with Traumec Tecnologia e Implantes, Brazil). The effectiveness of the fixators will be evaluated by the degree of displacement of the bars, using a mathematical formula, using a lateral chest X-ray in the immediate postoperative period (d0) and another image from the end of the period analyzed (dX), 15, 30, 90 and 180 days after the surgical procedure; evaluation of postoperative pain through the numerical pain scale; use of validated questionnaires on quality of life (physical and mental health) using two instruments, SF-36 and PEEQ. All data obtained between the two groups will be submitted to descriptive and inferential statistics.

Population to be studied: 20 individuals with pectus excavatum will be selected to undergo minimally invasive repair of pectus excavatum (MIRPE). Participants will be randomized into two groups: control and intervention group. In the latter, two metal bars and the bridge model fastener will be used as proposed in this study. The preoperative evaluation consists of anamnesis, physical examination, and laboratory tests. An electrocardiogram and echocardiogram will be performed to assess the participants' cardiac function. A computed tomography (CT) scan of the chest will also be performed to obtain the Haller index, as well as an analysis of lung volumes and thoracoabdominal kinematics and diaphragmatic mobility. Participants will also answer the quality of life questionnaires that will be repeated postoperatively. Participants will undergo minimally invasive repair of pectus excavatum (MIRPE) with one or two metal bars according to randomization. In the postoperative period, the displacement of the metal bars will be evaluated through chest X-ray and pain scale evaluation.

Measurement of lung volumes in liters (L) will be obtained indirectly through optoelectronic plethysmography.

The displacement of the bars measured in millimeters (mm) in the lateral chest X-ray in the immediate postoperative (d0) and at the end of the period analyzed (dX) considering the distance between the upper point of contact of the bar with the sternum and the most posterior and superior point of the body of the sternum. The bar displacement index is calculated according to the formula: d0 - dX / d0 x 100.

Measurement of the craniocaudal displacement of the left branch of the portal vein in millimeters (mm) by ultrasonographic examination as a measure of diaphragmatic mobility.

The Numerical Pain Rating Scale (NPRS) is a subjective measure in which individuals rate their pain on an eleven-point numerical scale. The scale is composed of 0 (no pain at all) to 10 (worst imaginable pain).

The Short-Form-36 Health Survey (SF-36) is a multidimensional instrument to assess health-related quality of life. It comprises two summary subscales: (1) the physical component summary features aspects of 'physical functioning', 'physical role functioning', 'bodily pain', and 'health in general' and (2) the mental component summary is based on the dimensions 'social functioning', 'emotional role functioning', 'vitality', and 'mental health'. Higher scores are indicative of better health.

The Pectus Excavatum Evaluation Questionnaire (PEEQ) consists of 12 questions for patients which result can vary from 21 to 40; and with 13 questions for their parents which result can vary from 13 to 52 with bigger numbers representing better quality of life.

Inclusion Criteria: Participants over 12 years of age; Pectus excavatum; Haller index > 3.25 Exclusion Criteria: Associated congenital anomalies; Unable to answer the quality of life questionnaires; Congenital heart disease; Chronic immunosuppression. Previous chest surgery or pleural drainage Associated coagulopathies and/or use of anticoagulant medications

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