What factors predict recurrence of a spontaneous pneumothorax?

The institutional review board approved this study. From 2005 to 2010, 221 patients requiring surgery due to SP were included in this retrospective study conducted at the University of Occupational and Environmental Health. Preoperative investigations included chest radiographs and a high-resolution computed tomographic (CT) scan of the thorax. Six patients with ipsilateral lung cancer and 1 with lymphangioleiomyomatosis (LAM) were excluded from the analyses. Finally, a total of 214 patients were included in the present series. The indications for surgical treatment of patients with SP included a persistent air leak, tension pneumothorax, and obvious existence of bulla lesions at first presentation, hemopneumothorax, the occupation of patient, and ipsilateral or contralateral recurrences. Data were collected retrospectively for all patients and included a detailed history, age, sex, and smoking habits, past history of episodes of pneumothorax, treatment modalities, and surgical details. The postoperative variables assessed included the use of pleurodesis, postoperative complications, duration of chest drainage, and length of hospital stay. The patients were discharged from the hospital after surgery, and the follow-up data were collected via the outpatient department.

All patients underwent general anesthesia and single lung ventilation with a double-lumen endotracheal tube and were placed in the lateral decubitus position. The 5- or 10-mm 0° video thoracoscope was inserted in the 7th intercostal space in the midaxillary line, making use of the hole made for the preoperative drainage tube. After inspection of the thoracic cavity, one or two additional ports were placed. The 5- or 10-mm working ports were placed in the 5th intercostal space between the scapula tip and anterior axillary line. The blebs were grasped with an endograsp and excised with the endo-GIA stapling device (Auto Suture Company Division, United States Surgical Corporation, Norwalk, USA) or ECHELON device (Ethicon Endo-Surgery, Inc; Cincinnati, Ohio) or were hand stitched. Buttress stapling was performed by polyglycolic acid (PGA) felt (Neoveil, Gunze Ltd, Kyoto, Japan) or DUET TRS (Covidien Autosuture, Mansfield, MA, 131 USA). The covering technique was performed using a PGA sheet (Neoveil) or surgical absorbable hemostat (Ethicon Endo-Surgery) with fibrin-glue (Beriplast P; Marburg, Germany or Bolheal: The Chemo-Sero-Therapeutic Research Institute, Kumamoto, Japan). An air leak test was performed under a pressure loading of 20 cm H₂O. A chest tube was placed through one of the port sites. The surgery was performed by a surgical team including one surgical consultant, and procedures were selected based on the intraoperative situation. A total of 190 and 11 patients, repectively, underwent device and hand stitching for blebs. Both methods were applied for 9 cases, and 4 cases were treated by abrasion alone. Therefore, these 13 cases were excluded, and the surgical method was eliminated from our logistic regression models.

All patients were extubated in the operating room. The chest tube was connected to an aspiration system, and negative suction of 5-or 10 cmH₂O was applied. Intercostal drains were removed when the underlying lung was expanded with no residual air leak. Postoperative pain was primarily controlled by means of a thoracic epidural block, and oral analgesic medication was administered when necessary. Patients were discharged from the hospital when they were fully mobile. A follow-up was conducted for all patients. The mean follow-up and relapse free period were 391 and 67 days, respectively.

In all, 214 patients were studied in this retrospective review. The clinicopathological characteristics of the patients are shown in Table1. All of the patients were Japanese, consisting of 182 males and 32 females in this series, with a mean age of 38.8 years (range 14–94 years). A summary of the details of all of these cases is given in Table1. The number of patients with and without a smoking habit was 75 and 139, respectively. One hundred three and 111 were right- and left-sided SP, respectively. One hundred seventy-seven (82.7%) were located on the top of the lung. Forty-four (20.6%) patients had a comorbid condition. The summary of comorbidities is given in Table2. We compared the clinicopathological characteristics between recurrent and non- recurrent cases. One hundred thirty-four were first-episode patients, while 80 patients had either an ipsilateral or a contralateral recurrence. There were 35 (16.4%) postoperative recurrences. The differences in the age, gender, lesion site, location, ISP, and CSP, did not reach statistical significance between the two groups. However, the incidence of recurrence was higher in the subjects without a smoking history, those with comorbidities, and those who had previously undergone surgery for ISP.

One hundred eighty-nine (88.3%) subjects underwent VATS, while an open thoracotomy was carried out on 25 patients. Concerning the intraoperative factors, there were no significant differences in the approach, buttress stapling, covering, surgeon, or length of the operation. The postoperative recurrence rate was higher in subjects who underwent hand stitching than machine stitching for blebs (Table3). There were no significant differences in the perioperative outcomes (Table4). All complications are listed in Table5. The postoperative course was uneventful in 199 (93.0%) patients and 15 (7.0%) complications were observed, while no intraoperative or in-hospital deaths were observed.

Logistic regression models indicated that a history of non-smoking, the existence of comorbidities, and a previous operation for ISP were predictive factors for postoperative recurrence (Tables6 and7).