Laparoscopic Repair of Diaphragmatic Perforation with Colonic Herniation Following Hepatic Radiofrequency Ablation: A Case Report

Background: Diaphragmatic hernia is a rare complication after hepatic radiofrequency ablation (RFA). We herein present a case of a patient who underwent laparoscopic repair of diaphragmatic perforation with colonic herniation occurring 12 months after hepatic RFA. Case presentation: An 80-year-old man underwent RFA under computed tomography guidance using a cool-tip radiofrequency probe with a short trans-thoracic root for hepatocellular carcinoma in segment VIII. Twelve months later, he developed a large amount of right pleural effusion and a right diaphragmatic hernia containing the colon and mesentery. After drainage of the right pleural effusion, the patient underwent laparoscopic repair of the diaphragmatic perforation with colonic herniation. Severe adhesion was noted between nearly the entire herniated colon and lung; however, we were able to remove the herniated colon from the thoracic cavity safely. Bowel resection was not required. Finally, simple running sutures of the diaphragmatic defect using 2-0 Vicryl were laid down. There were no postoperative complications, and the patient was discharged nine days after surgery. Conclusions: Diaphragmatic hernia is rare but should be recognized as a late complication following hepatic RFA. Surgical repair of a diaphragmatic hernia, including minimally invasive surgery using the laparoscopic approach, especially for patients with cirrhosis, should be considered in order to avoid acute intestinal obstruction or perforation.


Introduction
Radiofrequency ablation (RFA) is a minimally invasive treatment for hepatocellular carcinoma (HCC) and widely accepted as an effective treatment for HCC [1,2]. The algorithm of the National Comprehensive Cancer Network guideline states that RFA is categorized as locoregional therapy, and tumors ≤3 cm are optimally treated with RFA [3]. Recent developments in RFA technology have made it possible to necrotize a large volume of tissue (≥3 cm in diameter) [4,5]. RFA was reported to be relatively safe, with a mortality rate of 0.3% [6]. However, major life-threatening complications, including intestinal perforation, biliary stenosis, and tumor rupture, occasionally develop after RFA [2].
Diaphragmatic hernia is defined as the protrusion of the abdominal viscera into the thoracic cavity through a defect in the diaphragm, usually caused by traumatic injury or as a complication after abdominal surgery [6][7][8][9]. Diaphragmatic hernia after RFA is very rare and was unrecognized as a complication after RFA until recently, when it was reported as a delayed complication of RFA [10][11][12][13][14][15][16]. To treat diaphragmatic hernia, open laparotomy has generally been used. However, only two cases of laparoscopic treatment have recently been reported for the treatment of diaphragmatic hernia after RFA.
We herein report a rare case of a patient who underwent laparoscopic repair of diaphragmatic perforation with colonic herniation 12 months after hepatic RFA.

Case Report
An 80-year-old man with a history of hepatitis C cirrhosis was admitted to our hospital for the treatment of HCC in segment VIII, 11 mm in diameter ( Figure 1a). RFA was performed under computed tomography (CT) guidance using a cool-tip radiofrequency probe (Figure 1b). HCC was approached using a short trans-thoracic route.
We tried to induce artificial pleural effusion before RFA, but he had adhesion in the thoracic cavity, so this was not possible. Twelveminute ablation was performed. After the treatment, he developed mild pneumothorax without hypoxemia; however, he recovered without any thoracic drainage. He was discharged three days after RFA. A large hypovascular area corresponding to the treated zones was confirmed by CT (Figures 1c and 1d). Twelve months later, he had been suffering from dyspnea for two weeks and presented to another hospital. He had pleural effusion in the right thoracic cavity and was referred to our hospital for treatment. On admission, he had mild right-sided chest pain and hypoxemia. There was no history of chest or abdominal trauma. Laboratory tests showed severe hypoalbuminemia with serum albumin levels of 1.8 g/ dL. Aspartate aminotransferase and alanine aminotransferase levels were elevated to 263 U/L and 125 U/L, respectively. C-reactive protein levels were mildly elevated to 4.31 mg/dL. Hemoglobin levels and platelet counts were mildly decreased to 13.3 g/dL and 12.8 × 10 4 / µL, respectively. Child-Pugh classification was B. A chest radiograph showed a large amount of right pleural effusion and bowel gas in the right thoracic cavity (Figure 2a). CT showed a large amount of right pleural effusion and a right diaphragmatic hernia containing the colon and mesentery. A diaphragmatic defect was visualized by coronal CT images ( Figure 2b). Fortunately, the herniated colon was well-enhanced, and there were no symptoms of strangulation or obstruction.
We first performed a tap of the pleural effusion and confirmed that the pleural effusion was sero-bloody discharge and did not contain any bacteria. Closed drainage of the pleural cavity was administered. After drainage of the right pleural effusion, since repairing the hernia laparoscopically was believed to reduce the postoperative complications in patients with liver cirrhosis, the patient underwent laparoscopic repair of the diaphragmatic perforation with colonic herniation.
We fixed the patient in a left semi-lateral position and inserted four ports (Figure 3a). Transverse colon with omentum was herniated to the thoracic cavity via the approximately 5 cm perforated hole in the diaphragm (Figure 3b). Thermal damage to the diaphragm was confirmed to be adjacent to the RFA-treated region. Due to the difficulty in pulling down the whole colon through only the initial diaphragmatic hole, we opened the diaphragm about 10 cm in length. Severe adhesion was noted between nearly the entire herniated colon and lung ( Figure  3c). We carefully detached the herniated colon from the lung and were ultimately able to remove the colon safely from the thoracic cavity ( Figure 3d). We made an additional incision (4 cm long) around the navel and directly confirmed the good blood flow of the herniated colon and lack of any injury to the transverse colon. Bowel resection was not required. Finally, thoracic irrigation and simple running sutures of the diaphragmatic defect using 2-0 Vicryl (Ethicon co. Ltd, NJ, USA) were performed (Figures 3d and 3e). The overall surgery time was 308 minutes, and the amount of bleeding was 401 ml. There were no postoperative complications, and the patient was discharged nine days after surgery. The patient did not develop recurrence of diaphragmatic perforation in 4 months following the operation.

Discussion
Since its introduction, RFA has become a universally prevalent procedure due to its lower invasiveness. However, with the accumulation of cases, late-onset complications, such as heat damage have become evident. Mulier et al. [17] reported that the incidence of diaphragmatic injury after RFA was 0.1%. Diaphragmatic perforation and herniation are rare but serious complications of hepatic RFA. Since Koda et al. [14] reported the first case of diaphragmatic hernia following RFA, there have been only 12 reported cases of RFA-associated iatrogenic diaphragmatic hernia written in English according to PubMed (Table 1), [10][11][12][13][14][15][16][18][19][20][21].
The cause of diaphragmatic hernia after hepatic RFA is thermal damage to the diaphragm [3]; however, the cause of delayed perforation is unclear. Nomura et al. [18] mentioned that the temporal adhesion between the thermally-damaged diaphragm and the liver surface released due to the atrophy of the cirrhotic liver and develop a delayed diaphragmatic hernia. Singh et al. [10] advocated that the thermal injury to the diaphragm did not cause a defect immediately, with the partial thermal injury instead resulting in an inflammatory response that led to fibrosis, ultimately weakening and causing a defect.
Various techniques have recently been used to minimize the risk of diaphragmatic injuries and associated complications with RFA. Intraperitoneal saline injection was introduced to prevent diaphragmatic  injury and avoid contact with adjacent visceral organs during hepatic RFA. [22] Diaphragmatic hernia is rare but should still be recognized as a late complication following hepatic RFA. The possible presence of diaphragmatic hernia following hepatic RFA adjacent to the diaphragm should be considered, especially in patients developing bowel obstruction, dyspnea, chest pain, or pleural effusion. Surgical repair for diaphragmatic hernia should be considered in order to avoid acute intestinal obstruction or perforation.
Of the 11 reported cases of diaphragmatic hernia after RFA, two were treated conservatively, and were successfully followed up without any symptoms [12,21]. The remaining 9 patients were required surgical treatment. Open hernia repair was usually performed in the earlier cases. However, owing to modern advances in laparoscopic surgery laparoscopic repair has frequently been performed in more recent cases. Laparoscopic approaches to diaphragmatic repair have been introduced in the elective setting [10,18]. The laparoscopic approach is widely accepted as the safer surgical approach in patients with HCC and cirrhosis reducing ascites or pleural effusion than conventional laparotomy [23]. In addition to reducing the risk of postoperative complications due to liver cirrhosis, a laparoscopic approach also provides a better intraoperative view than an open procedure. In our case, the patient had severe adhesion between almost the entire herniated viscera and the lung. Had we tried to treat this diaphragmatic hernia by open laparotomy, it might have been difficult to achieve detachment of the adhesion between the herniated viscera and the lung in the thoracic cavity via the diaphragm. In addition, larger skin incision and thoracotomy would have been necessary to acquire a better intraoperative view. Laparoscopic surgery may have advantages over open laparotomy in the surgical treatment of adhesion in the thoracic cavity via small diaphragmatic hernia, especially in cases having severe adhesion between the herniated abdominal viscera and the lung.
Diaphragmatic hernia sometimes induces the development of strangulated ileus, necessitating additional bowel resection. In the present study, it was difficult to confirm a sufficient blood flow and the absence of intraoperative injury in the herniated colon after removing the herniated viscera from the thoracic cavity using laparoscopy alone, so we made an additional incision around the navel (4 cm long) and directly confirmed the good blood flow and absence of intraoperative injury of the herniated colon. A pure transthoracic approach-without an abdominal incision-would be possible for diaphragmatic hernia repair; however, it would be difficult to safely confirm the blood flow and the absence of any injury to the herniated viscera by this approach.
In conclusion, diaphragmatic hernia is rare but should be recognized as a late complication following hepatic RFA. Surgical repair of a diaphragmatic hernia, including minimally invasive surgery using the laparoscopic approach, especially for patients with cirrhosis, should be considered in order to avoid acute intestinal obstruction or perforation.