Postoperative Residual Pleural Space: A Risk Factor for Chest Wall Hernia After Thoracoscopic Surgery

Abstract

Case series

Patients: Male, 71-year-old • Male, 60-year-old

Final Diagnosis: Chest wall hernia

Symptoms: Chest wall swelling • cough

Clinical Procedure: —

Specialty: —

Objective: Unknown etiology

Background

Chest wall hernia and residual pleural space are known complications after thoracoscopic anatomical lung resection. Some risk factors for chest wall hernia have been described; however, residual pleural space has never been described as one of them. We present 2 cases suggesting that postoperative residual air space can represent a newly identified risk factor for chest wall hernia.

Case Reports

Case 1: A 71-year-old man developed a postoperative chest wall hernia at the fourth intercostal incision level 1 week after a 3-port thoracoscopic left lower lobectomy for early-stage non-small cell lung carcinoma. He was not known to have any described risk factors for postoperative chest wall hernia, but his postoperative course was complicated by a residual pleural space.

Case 2: A 60-year-old man developed a postoperative chest wall hernia at the fourth intercostal incision level, diagnosed 5 months after a right apical upper lobe segmentectomy by 3-port thoracoscopy for early-stage non-small cell lung carcinoma. She was not known to have any risk factors for postoperative chest wall hernia; however, her postoperative course was also complicated by a residual pleural space.

Conclusions

We suggest that air flow through the thoracoscopic incision, due to residual pleural air, could impede wound healing and favor chest wall hernia. Adaptation of the closure technique for video-assisted thoracic surgery incisions in patients at risk may help prevent postoperative chest wall hernias. These cases highlight the possibility that residual pleural space could be a newly identified risk factor for postoperative chest wall hernia and propose potential preventive measures.

Introduction

Chest wall hernia is defined as a reducible chest wall mass that contains air or lung protruding beyond its normal boundaries through an abnormal opening in the thoracic enclosure [1,2]. Chest wall hernia has been described in the literature after thoracic surgery procedures, either after thoracotomy or after video-assisted thoracic surgery (VATS) [3,4]. VATS is a widely used minimally invasive technic in thoracic surgery, in which the surgeon uses a thoracoscope and small incisions for various procedures [5]. VATS has been shown to reduce pain, shorten the length of hospitalization, and decrease postoperative complications [6].

The pathophysiology of postoperative lung herniation is generally explained by some risk factors, including large or anterior intercostal opening, significant emphysema, chronic cough, or non-rigorous closure of the tissue layers [3,4]. We describe 2 patients with incisional chest wall hernias after VATS pulmonary resections, with no typical risk factors present. However, we identified in both patients a residual pleural air space after surgery. Residual pleural space is defined as a free volume in the pleural space resulting from a pulmonary resection [7]. We speculate that the repeated propulsion of air deriving from the residual space through the chest wall incision in the subcutaneous tissue and back during coughing impeded the healing of the chest wall and favored the formation of a persistent incisional chest wall hernia. Despite the description of several risk factors in the literature, the pathophysiology of chest wall hernias after VATS remains poorly understood [4,5]. To the best of our knowledge, no prior studies have investigated the role of postoperative residual pleural space in this complication. We suggest that patients at risk for residual pleural space [8] should be considered as at risk for postoperative chest wall herniation. Chest wall closure techniques should be adapted and reinforced in these specific cases. We highlight in this case report 3 main clinical topics: first, postoperative chest wall hernia as a rare but existing complication of VATS; second, the possible role of residual pleural air space as a risk factor for the development of postoperative chest wall hernia; and third, the need to consider reinforced closure techniques, such as pericostal stitches, when a residual pleural space is anticipated.

This report describes 2 cases of chest wall hernia associated with residual pleural space after VATS for early-stage non-small cell lung carcinoma. We present these 2 cases in accordance with the CARE case report guidelines.

Case Reports

Case 1

A 71-year-old man underwent 3-portal VATS left lower lobectomy with lymph node dissection for a lung adenocarcinoma. Surgical incisions were performed following a standardized technique, as described by Mitchell in 2013 [9]. Intraoperatively, an extensive adhesiolysis was required. The 4-cm utility incision at the level of the anterior fourth intercostal space was closed in layers, including the chest wall muscles, however, without reapproximating the ribs by use of a pericostal stitch.

The immediate postoperative course revealed a residual air space on chest radiography, which persisted after chest drain removal. The clinical and radiological follow-up 1 week later demonstrated, upon coughing, an intermittent swelling of the skin with air accumulation at the level of the fourth intercostal space incision and, on chest radiography, a persisting postoperative residual air space. On palpation, the skin was soft and non-tender, and the air was reducible. This raised suspicion for a chest wall hernia. Given the early postoperative stage, conservative management was favored. One month later, the patient still reported having the thorax wall swelling during coughing (Figure 1A, 1B), and chest radiography showed the persistence of a residual pleural space (Figure 1C). Differential diagnosis could have included a liquid collection (seroma, abscess); however, clinical assessment, imaging, and the absence of inflammatory sign confirmed the diagnosis of postoperative chest wall herniation.

Figure 1.

Case 1: Subcutaneous air protrusion and persistent residual air space after surgery. Fourth intercostal incision site 1 month after surgery is shown during (A) inspiration and (B) coughing, revealing the subcutaneous protrusion of air through the chest wall incision. (C) Chest X-ray reveals a persistent residual air space (arrows).

A surgical repair of the chest wall hernia was performed, revealing a 5-cm “hernia sac” and the absence of the intercostal and chest wall muscle layers (Figure 2). The chest wall defect was closed by use of a Vicryl mesh (Ethicon, Cincinnati, OH, USA), which was sutured into the intercostal defect, followed by dissection of the chest wall muscles, which were then closed by interrupted 1-Vicryl (Ethicon) sutures. The patient was discharged at postoperative day 3, without recurrence during the 6-month follow-up.

Figure 2.

Case 2: Intraoperative view of large incisional hernia. Image shows intraoperative situs with a large incisional hernia at fourth intercostal space incision and absence of intercostal and chest wall muscle layers.

Case 2

A 60-year-old man underwent 3-port VATS right apical segmentectomy, with mediastinal lymph node sampling, which was performed for a bronchial cyst. The fourth intercostal-space utility incision was closed in layers, including the chest wall muscles but without rib approximation, with a pericostal suture. The postoperative course was uncomplicated. Five months after the surgery, the patient reported having subcutaneous swelling with coughing, at the level of the fourth intercostal incision. Clinical examination showed a non-tender, soft, and reducible collection, without inflammatory sign. Computed tomography (CT) showed a small residual pleural space and a subcutaneous air bubble at the level of the fourth intercostal incision (Figure 3), suggesting the presence of an incisional chest wall hernia. Due to the 5-month delay from the surgery, we did not expect a spontaneous resolution of the hernia and performed chest wall hernia repair. During the operation, a hernia sac was found and excised. The ribs were approximated using several 2-Vicryl (Ethicon) pericostal stitches. The chest wall musculature was dissected and closed by interrupted 1-Vicryl (Ethicon) sutures. The postoperative course was uneventful, and the patient was discharged on postoperative day 4, without recurrence during the 6-month follow-up.

Figure 3.

Case 2: Computed tomography (CT) shows residual pleural space and incisional chest wall hernia. CT 5 months after video-assisted thoracic surgery apical segmentectomy reveals a residual space and subcutaneous air at the level of the fourth intercostal incision site (arrows), suggesting the presence of an incisional chest wall hernia.

Discussion

In this case report, we presented 2 patients with postoperative chest wall hernia that was associated with a postoperative residual pleural space. We hypothesize that residual pleural space could be a newly described risk factor for postoperative chest wall hernia.

Only a few case reports describe chest wall hernias as a complication of VATS [3,4,10–12], and the incidence of this complication is unknown. However, several potential risk factors for incisional chest wall hernia development after VATS procedures have been described in the literature, including increased intra-thoracic pressure, poor wound healing, and surgical technique, such as intercostal incision larger than skin incision, no pericostal closure, and non-rigorous closure of soft tissue layers [3,11,12].

In our 2 patients, none of those predictors for incisional chest wall hernia development could be identified. For this reason, we aimed to find another possible cause for this atypical presentation, as it suggested an alternative mechanism. We identified that our 2 cases presented a residual pleural space. We hypothesize that the contained air in the residual pleural space is propelled during coughing through the chest wall incision into the subcutaneous tissue and during inspiration back in the chest cavity. These repeat propulsions of air through the chest wall incision during respiration and coughing in the postoperative course might impede the healing process of the chest wall incision and the overlying musculature, while creating a permanent incisional chest wall hernia. In both patients, the incisional hernia was found at the fourth intercostal incision site. This finding might endorse our hypothesis, since a residual pleural space is usually located in the upper part of the chest cavity, and the fourth intercostal space incision is usually larger-sized, and both might favor this repeat propulsion of air through the chest wall incision. A detailed literature review revealed that none of the previous reports specifically addressed the role of a residual pleural space in hernia formation. Our case contributes by refining and improving the understanding of VATS postoperative complications.

Residual pleural spaces are found in 10% to 20% of patients after anatomical lung resections [13]. Mueller et al described several risk factors for postoperative residual pleural space development, such as reduced lung compliance, restrictive lung disease, a small remaining lobe, extensive adhesiolysis, previous thoracic surgery, and radio-/chemoinduction therapy [8]. The patient in case 1 had an extensive adhesiolysis during surgery, which may explain the postoperative residual pleural space. The patient in case 2 has no risk factors for residual pleural space. Patella et al [14] described in their study a reversible phrenic nerve paralysis to manage residual pleural space after lung resection. This can be a solution to reduce complications due to postoperative pleural space in selected patients with known risk factors.

There are no technical guidelines concerning the closure technique of the thoracoscopy incisions, and the general practice is to close the thoracic wall layer by layer from the muscle to skin, without closure of the intercostal space [9]. However, we suggest, that in cases of known predictors for incisional chest wall hernia development, closure of the fourth intercostal incision site by pericostal stitches may be necessary. Our 2 cases suggest that the same probably holds true for residual pleural spaces after VATS resection. Consequently, if a postoperative residual pleural space is anticipated during surgery, closure of the intercostal space by a pericostal stitch should be considered.

Finally, it is important to acknowledge the limitations of this case report. This is a small patient group, and the inherent retrospective nature and selection bias of this report limits the generalization of this newly suggested risk factor. Moreover, this case report does not include patients operated with the latest surgical techniques, such as uniportal VATS [15]. Future studies including more patients will be necessary to confirm the role of residual pleural space in the physiopathology of postoperative chest wall hernia. The better understanding of the etiology of this complication could lead to preventive measures and adaptation of the procedures.

Conclusions

These cases highlight the possibility that residual pleural space could be a newly identified risk factor for postoperative chest wall hernia and propose potential preventive measures. Identifying patients at risk of postoperative chest wall hernia after VATS anatomical lung resection appears to be important to reduce postoperative morbidity and the need for additional surgery. To prevent incisional chest wall hernias after VATS procedures, we suggest closing the fourth intercostal utility incision site by a pericostal stitch in patients at risk, including situations in which a postoperative residual pleural space is anticipated.