OBJECTIVE: To investigate the clinical efficacy of combined partial thoracic reformation with a tipped muscle flap for the treatment of intrathoracic tissue defects after abscess thorax. METHODS: After the occurrence of abscess chest, the window was opened and cleared in a timely manner, adequate drainage was achieved, and the appropriate time was selected for intra-thoracic repair. The fistula was closed after partial removal of the ribs, and the dead cavity was strengthened and filled with a live multiple muscle flap tissue. Results Thirty-five patients with a mean age of 56.3 years were admitted. Among them, 19 patients had bronchopleural fistula, 3 patients had pulmonary pleural fistula, 3 patients had esophageal pleural fistula, 2 patients had gastropleural fistula, 2 patients had esophagobronchopleural fistula, 3 patients had esophageal rupture, 2 patients had post-traumatic abscess chest, and 1 patient had post-heart bypass abscess chest. 6 patients were discharged with drainage tube, and the rest of the patients healed successfully at one time. Five of the six patients were reoperatively healed, and one chose to be treated with a tube. Conclusion Choosing the proper timing for repair, indeed closing the fistula, fully considering the previous destruction of blood vessels, combined application of multiple muscle flaps, and upward shift of the muscle flap transfer point, the method of partial thoracic reformation with muscle flap transfer can effectively treat the refractory giant trauma left after septic chest. Stump fistulas occurring after thoracic surgery, such as bronchopleural fistulas and esophagogastric anastomotic fistulas, are a serious complication after lung resection or esophageal cancer surgery, and air in the lung or esophageal or gastric contents fistulas into the pleural cavity after the occurrence of stump fistulas, often leading to pus thorax. Management of abscess thorax after its occurrence is tricky, with high mortality, long hospital stay, and difficult repair [1-3]. Prompt opening and drainage is needed to control infection after the occurrence of an abscess chest, which creates a large intrapleural dead space. The treatment of post-abscess chest trauma includes controlling infection, promoting granulation tissue growth, choosing the proper timing of surgery, properly treating the fistula, and selecting appropriate muscle flap tissue with good blood supply to fill the dead cavity [2-6]. Only a few units in China have carried out the treatment [7-8], and most of them are reported as individual cases, and our relevant data are summarized and reported as follows. 1. Data and methods (1) Clinical data From January 2010 to July 2013, 35 patients, 28 males and 7 females, aged 14-72 years, average 56.3 years, were admitted. The causes of pus thorax occurred in 19 cases of bronchopleural fistula, 3 cases of pulmonary pleural fistula, 3 cases of esophageal pleural fistula, 2 cases of gastropleural fistula, 2 cases of esophagobronchopleural fistula, 3 cases of esophageal rupture, 2 cases of post-traumatic pus thorax, and 1 case of post-heart bypass pus thorax. At the time of admission, all patients had undergone thoracic cavity opening and drainage surgery in external hospitals or thoracic surgery. (2) Surgery method The surgery was performed in two steps. In the first step, after the diagnosis of abscess chest was confirmed, the window was opened and cleared, and the drainage was changed. The skin is cut on the surface of the abscess cavity, and the ribs on the surface of the abscess cavity are removed, mostly 2-3 partial ribs, so that the window is opened as wide as possible. The infected pus moss and necrotic tissues are removed from the abscess cavity, the wound is flushed with hydrogen peroxide, 1‰ chlorhexidine solution, and surgical Ertel, the wound is filled with saline gauze for drainage, and the medication is changed regularly to control infection and promote granulation tissue proliferation. In the past, the first step of surgery was mostly done by thoracic surgeons, who often did not pay attention to the blood supply of the pectoralis major or latissimus dorsi muscle, cutting off the trophoblastic vessels and sacrificing the valuable available tissues. After adequate preparation of the trauma, the second-stage muscle flap is transferred, the fistula is repaired, and the dead space is filled with tissue of good blood supply to close the trauma. The selection of the muscle flap is based on the location of the original thoracic surgical incision, the open incision, and the location of the septic chest. The selection of the muscle flap is based on a good blood supply, the point of rotation of the flap, and the appropriate length to facilitate the flap’s ability to reach the distal end of the dead space. In general, one side of the lung is often associated with diaphragm elevation and mediastinal deviation to the affected side after lung resection, and most of the dead cavities in pneumothorax are located above the thoracic cavity. The commonly used flaps are combined muscle flaps such as pectoralis major muscle flap, latissimus dorsi muscle flap, and latissimus dorsi anterior serratus muscle flap, rectus abdominis muscle flap, and pectoralis major muscle mammary flap. A free muscle (skin) flap is chosen when a tipped flap cannot be used. The skin is incised along the perimeter of the fistula, the incision is moderately extended, and the flap is peeled away to reveal the muscle tissue used to form the muscle flap in the first place. Appropriate removal of several ribs on the surface of the dead cavity, on the one hand, shifts the rotation point of the muscle flap upward, improves the utilization rate of the muscle flap, and opens the intra-thoracic transfer pathway of the muscle flap; on the other hand, after appropriate removal of some ribs, partial thoracic reformation is performed, which can reduce the dead cavity and save tissue. The thickened pleural tissue is cut after rib resection to facilitate tissue collapse. The closure of the fistula is one of the difficulties of surgery after rib resection revealing the fistula in the thoracic cavity [2]. We use different methods depending on the nature of the fistula, with a single fistula being repaired with a surrounding synovial flap and a foveal fistula being repaired with a resistant tissue patch. The wall of the pus cavity is scraped off with gauze held in oval forceps to roughen the smooth envelope and create a fresh wound. The wound was flushed with hydrogen peroxide, Neosporin solution, and antibiotic saline, and the surgical instruments were replaced. The formed muscle flap tissue is placed tension-free into the dead cavity in the thoracic cavity and fixed with sutures as close as possible to the tissue around the fistula, filling the dead cavity and enhancing the fistula repair. If the fistula is too deep to be fixed with the surrounding tissue, it is fixed with fibrin glue and sutured to the superficial surface of the muscle flap so that the flap does not slip out easily. A negative pressure drainage tube is placed around the fistula. Negative pressure drainage was also placed in the donor area of the flap. (3) Typical case Case 1: male, 63 years old, bronchopleural fistula occurred after lung resection for left-sided lung cancer, forming an abscess chest, open window drainage and drug exchange for 4 months, partial resection of 4 ribs to reduce the dead space while moving the muscle flap rotation point upward, and filling with pectoralis major muscle flap. (1) after open window drainage of abscess chest; (2) after partial resection of 4 ribs and formation of pectoralis major muscle flap; (3) filling of dead cavity with pectoralis major muscle flap; (4) mild deformation of the thorax after wound healing. Case 2: Male, 54 years old, bronchopleural fistula occurred after left pneumonectomy for lung cancer, open window drainage and drug exchange for 3 months, partial resection of 4 ribs, reduction of dead space, and filling with pectoralis major muscle combined with lateral chest wall tissue flap. (1) after opening and draining of abscess chest; (2) after preoperative CT showed a huge dead cavity in the chest; (3) after partial resection of 4 ribs and formation of a joint lateral chest wall tissue flap with the pectoralis major muscle; (4) after wound healing with mild deformation of the thorax. 2. Results The average hospital stay of this group of patients was 16 days, and there were no cases of death due to repair surgery in the perioperative period. The average time to repair the thoracic cavity was 2-38 months from the time of open surgery, with an average of 3.9 months. 29 of the 35 patients were successfully repaired in one operation, including those whose fistulas had been closed by dressing changes at the time of repair surgery. 3 patients with bronchopleural fistulas had postoperative fistula infections and were discharged with drains, and one patient refused reoperation and was informed that the patient needed a tube for life. The other two cases were successfully repaired and cured by reoperation six months later. In one case of esophageal pleural fistula, there was still a small amount of exposure when eating fluids after surgery, and the patient was discharged with a drainage tube, and the fistula healed on its own after 3 months, and the patient was readmitted and the drainage tube was successfully removed. The wound healed. All patients were successfully followed up for 2-30 months with a mean follow-up time of 6.42 months. All cured patients had no recurrence of intra-thoracic infection and all patients were satisfied or very satisfied. 3. Discussion: Intrathoracic infection often leads to the occurrence of pus in the chest cavity. Patients are often in depressed general condition with fever, elevated leukocytes, poor gastric function and high mortality. The first step of treatment requires timely release of pus, massive saline flushing of the wound, reserved scraping of pus moss to prevent damage to vital organs, open drainage, wound dressing, and infection control. Continuous irrigation with antibiotic saline can also be used. Timely chest opening and drainage is the key to treatment and can effectively reduce mortality [2-3]. After prolonged exchange treatment after opening a window often forms a huge intrathoracic tissue defect, which is a recognized therapeutic challenge in the field of thoracic and cardiac surgery. Choosing the proper timing of surgery for intrathoracic repair is one of the keys to treatment, which requires waiting for the infection to be controlled, the white blood cell count to fall to normal, the fever to subside, the general nutritional status to improve, and the granulation tissue to be fresh before performing intrathoracic muscle flap transfer and closing the chest cavity [2]. Generally, the medication is changed for more than 2-3 months, and in our group of cases, the repair was performed on average 3.9 months after the open surgery, and the longest case was changed in an outside hospital for more than 3 years. Traditionally, the treatment of abscess chest in thoracic and cardiac surgery is thoracic revision, in which a large part or all of the ribs on one side of the thorax are removed to induce collapse of the thorax to fill the dead space. The Clagett method has been used for nearly 50 years and is theoretically repeatable. The method is to close the fistula in the chest cavity with a muscle flap reinforced with antibiotic saline, remove the air from the chest cavity, close the skin tightly to achieve a water-tight seal (water-tight), and gradually absorb the saline in the chest cavity while the granulation tissue grows and closes the dead cavity. This method has not been clinically promoted [1]. Closure of the fistula is the key step of the procedure. Early occurrence of bronchopleural fistulae can be performed with local injection of sclerosing agents under bronchoscopy, which often requires several repetitions [8-9]. After the occurrence of septic chest wall opening and drainage, small fistulas can close by themselves with prolonged dressing changes. Fistulas that fail to close on their own are of two types, one or two isolated fistulas and the other is a honeycomb fistula that appears as multiple bubbles on irrigation and puffing tests. For isolated fistulas, we repair the fistula with reversed sutures around the thickened synovial tissue and then reinforce it with muscle tissue with good blood supply; for honeycomb fistulas, which are mostly pulmonary fistulas, we repair the fistula with a Nevi patch suture and then reinforce it with muscle tissue. After muscle tissue strengthening, a negative pressure drain was placed in a low position near the fistula. Six patients in our group were discharged with tubes, and all of them healed on their own after 1-3 months of continuous drainage and slow decannulation therapy, and the rest were discharged successfully with their tubes removed and wounds removed and healed. A prolonged abscess chest compresses the lung tissue and forms a huge dead cavity, except for a small dead cavity after months or years of prolonged exchange of granulation tissue, a muscle tissue flap alone often does not have enough tissue to completely fill the dead cavity [2,3,5,6]. The following methods can be chosen, (1) combined two or more muscle tissue flaps for repair, such as anterior serratus flap combined with latissimus dorsi flap, pectoralis major muscle combined with lateral chest wall subcutaneous fat as well as anterior serratus muscle flap to completely fill the dead space. (2) Muscle tissue flap combined with partial thoracic reshaping, after removing the upper and lower 2-3 ribs to reduce the dead space, the thoracic cavity is filled with combined muscle tissue flap. (3) Clagett’s method, in which the thoracic cavity is closed with a fistula reinforced with a muscle flap followed by intra-thoracic instillation of antibiotic saline. According to the size of the chest cavity, we choose to apply a muscle tissue flap with good blood supply to close the dead cavity, and at the same time carry out partial chest modification to repair the cavity, and achieve good treatment results. Most of the septic chests are accompanied by diaphragmatic uplift after window opening, and the dead cavity is often located at the upper end of the chest, and the commonly used muscle tissue flaps for filling the chest cavity are the latissimus dorsi muscle flap, the pectoralis major muscle flap, the anterior serratus muscle flap, the retrograde latissimus dorsi muscle flap, and the rectus abdominis muscle flap [1-7]. Depending on the amount of tissue needed, single or multiple muscle flaps are selected. When selecting a muscle flap, attention should be paid to chest incisions such as primary lung resection and the destruction of chest wall vessels by open drainage surgery. Because thoracic and cardiac surgeons are not very aware of the blood supply of the flap, clinical practice often encounters cases in which the thoracic and shoulder vessels, or the latissimus dorsi muscle, are cut off, and the blood supply of the selected muscle flap should be properly evaluated before surgery. Plastic surgeons and thoracic surgeons working together to design open incisions can effectively preserve the blood supply of local tissues. In order to effectively utilize the muscle flap tissue, partial excision of the ribs is required to achieve a superior shift of the transfer point of the muscle flap. The placement of the drainage tube is one of the keys to the success of the procedure. The drainage tube should be placed low near the fistula and not directly on the fistula surface. This allows timely drainage of air and other leaks due to poor fistula repair without interfering with the healing of the fistula [2]. The negative pressure drainage tube near the fistula should be placed for a long time, about 2-3 weeks in our group, and then removed after the fistula is healed around the fistula and the muscle flap, relying on the collapse and extrusion of the tissue to make the drainage tube mouth heal. Choosing the proper timing of repair surgery, indeed closing the fistula, fully considering the previous destruction of blood vessels, the combined application of multiple muscle flaps, the upward shift of the muscle flap transfer point, and the use of partial chest reformation with muscle flap transfer can achieve effective treatment of the refractory trauma left after septic chest.