Diaphragmatic hernia after radiofrequency ablation of liver tumor − case report and literature review

Summary

Introduction: Radiofrequency ablation is an effective management modality for irresectable primary and secondary liver tumors. Some serious complications have been reported including diaphragmatic hernia. Diaphragmatic hernia is the protrusion of abdominal viscera into the thoracic cavity through a diaphragmatic defect and usually classified into congenital and acquired. After RFA, diaphragmatic hernia is a rarely-reported complication.

Case report: A 62-year-old male patient, known to have liver cirrhosis on top of hepatitis C virus, presented to the emergency department with generalized abdominal pain and vomiting four months after having a RFA procedure for a liver tumor in segment VIII. Computed tomography showed diaphragmatic hernia with strangulated terminal ileum in the chest. Emergency laparotomy was performed with resection of an ileal segment and creation of double barrel ileostomy. The patient was discharged in a good condition after tolerating oral intake.

Conclusion: Radiofrequency ablation is an effective modality for management of the primary and secondary liver tumors. Despite its safety, some complication may happen owing to its thermal effect and the associated patient’s general condition. Many techniques have been described to decrease its thermal injury. Diaphragmatic hernia is a rare complication after RFA. Its clinical presentation may be confusing and it may occur as early as one month after RFA. Its diagnosis depends mainly on computed tomography. Emergency surgical management is the standard approach.

Keywords:

radiofrequency ablation – postoperative complications – liver tumors – hepatocellular carcinoma – diaphragmatic hernia

INTRODUCTION

Radiofrequency ablation (RFA) is one of the relatively new treatment modalities for primary and secondary hepatic malignancies [1]. Although being an invasive procedure, it is considered to be relatively safe with results shown to be comparable to hepatic resection [2,3]. Yet, some serious complications have been reported after RFA such as hepatic abscess, bowel perforation, fistula formation, and biloma [2].

Diaphragmatic hernia is defined as a protrusion of an intra-abdominal structure into the thoracic cavity and is usually classified as congenital and acquired. Acquired diaphragmatic hernia is mainly preceeded by diaphragmatic injury caused by blunt or penetrating trauma or iatrogenic injury [2,3]. Surgical intervention in the form of laparotomy and repair of the diaphragmatic defect has been widely accepted. Nonetheless, laparoscopic repair has been tried and proven successful in the treatment of such cases [2].

In this report, we present a case of an elderly male patient who developed a strangulated diaphragmatic hernia after RFA for hepatocellular carcinoma (HCC).

CASE REPORT

A 62-year-old male patient presented with generalized abdominal pain and persistent vomiting for three days to the emergency department. He was diagnosed with liver cirrhosis on top of hepatitis C infection for eight years.

Four months before this presentation, he underwent RFA for a 3.7cm hepatocellular carcinoma (HCC) lesion at segment VIII of the right hepatic lobe. The RFA procedure was done using a combination of conscious sedation and local anesthesia to the liver capsule along the planned RF electrode path. We used a combined approach of both ultrasound and computed tomography (CT) guidance as the ablated lesion was high and near the diaphragm (segment 8).The therapeutic strategy of the RFA consisted of including a peripheral margin of at least 0.5 cm of normal hepatic parenchyma surrounding the tumor and the entire tumor itself as soon as possible. A single overlapping ablation for the lesion was performed without creating artificial ascites. The mean duration of the complete RFA was about 20 minutes. The electrode path was cauterized during retraction of the electrode to minimize bleeding after ablation and to avoid track seedling. The procedure was tolerated well without any immediate complications.

Upon presentation, he was disoriented, hypotensive, and tachycardic. Abdominal examination showed generalized abdominal distension and hyper-resonant note on percussion. A nasogastric tube was inserted and drained 600 milliliters (ml) of bilious fluid over 2 hours. His laboratory works were significant for low hemoglobin levels, and low platelet count with deranged liver and renal functions tests (Tab. 1).

Urgent CT scan of the chest, abdomen, and pelvis revealed a diaphragmatic hernia through the right copula of the diaphragm. The terminal ileum was herniating into the thoracic cavity with possible closed loop obstruction and questionable viability of the herniated segment. The right lung was compressed with the left mediastinal shift (Fig. 1).

After resuscitation and stabilization, he underwent an emergency laparotomy. There was a 10cm defect in the right diaphragmatic copula, opposite to the liver lesion at segment VIII, with herniation of the terminal ileum. The herniated terminal ileum was successfully reduced. However, a 15cm segment of the ileum (approximately 40 cm from the ileocaecal valve) was resected owing to its strangulation with the creation of a double barrel ileostomy. The diaphragmatic defect was closed with double layers of Proline (size 1) and a right chest tube was inserted. The overall procedure duration was 120 minutes, and the estimated blood loss was 350 ml (Fig. 2).

Postoperatively, the patient was transferred to the intensive care unit and got extubated on the following day. He had a smooth postoperative recovery and gradually tolerated oral intake. On the sixth postoperative day, he was discharged home after satisfactory progression. He was followed up in the clinic for three months and did not report any postoperative complications.

DISCUSSION

Radiofrequency ablation is a popular minimally invasive procedure that is increasingly performed for irresectable primary and secondary liver tumors, especially HCC. Its effectivity depends on thermal ablation of the tumor. It provides a successful, less invasive alternative to surgical resection [4]. Currently, it is considered the standard HCC locoregional treatment for patients with up to three tumors that are three centimeters or less in diameter [5]. RFA is contraindicated for liver tumors located less than one centimeter from the main biliary duct or a bilio-enteric anastomosis [6].

Several approaches are described for RFA including image-guided percutaneous, thoracoscopic, laparoscopic, and laparotomy approaches. Image-guided percutaneous procedures are usually performed with conscious sedation under ultrasonographic, and/or CT guidance. The most commonly used needle is RITA Medical Systems (Mountain View, Calif ) [7]. Our team has eleven years of experience in the field of interventional radiology with about seven years of experience in the subspecialty of liver ablation procedures. We serve 25−30 patients every year with local ablation therapy namely RFA and microwave ablation.

Although RFA has been accepted as a relatively safe and promising technique for treating irresectable hepatic tumors with a low complication rate, it has a wide range of possible complications. The number of reported complications is increasing with the rising number of performed procedures. The complications are usually minor and can be classified into intrahepatic, extrahepatic, and systemic or early and late complications. A major complication is defined as any persistent complication for more than a week after RFA or that required further management.(8) RFA can induce major complications due to the associated unintended thermal injury such as hepatic abscess formation, intraperitoneal hemorrhage, biloma, pneumothorax, biliary stricture, bowel injury, and diaphragmatic injury and burn [9]. We use microwave ablation in many patients who have lesions where RFA is contraindicated, such as lesions very close to the gallbladder or bile duct. Unfortunately, we have not used irreversible electroporation (IRE) yet.

Diaphragmatic hernia (DH) is the protrusion of abdominal viscera into the thoracic cavity through a congenital or acquired diaphragmatic defect. Acquired diaphragmatic hernia is less common and usually occurs after blunt or penetrating trauma. Iatrogenic defects are not common and may be associated with surgical procedures for adjacent organs including the liver, lung, or spleen [10]. After RFA, diaphragmatic injury (DI), first reported in 2003 by Koda et al, is a rarely-reported complication [11]. DI has been reported with or without DH [12]. Head et al reported its incidence to reach up to 17% [13].

The exact cause of DI/DH is not identified with certainty. The most accepted explanation is the thermal effect of RFA. Others blamed the RFA technique and the needle type to cause a direct mechanical injury to the diaphragm. Several risk factors have been reported including the proximity of HCC to the diaphragm, and the transthoracic approach of RFA [12], expandable needle type, poor general condition, advanced cirrhosis, associated ascites, and/or pleural effusion [12]. The location of HCC in most reported cases was in segments V, VII, and VII [14].

It is hypothesized that DI starts as a small hole in the diaphragm, caused by the used needle, especially after transthoracic RFA. Others have proposed that thermal injury induces local inflammation leading to fibrosis and muscle weakness. In addition, the associated inadequate liver function hinders healing of the small DI. Such a small hole or fibrosis consequently enlarges, owing to the increased intra-peritoneal pressure and ascites, causing a diaphragmatic defect after a variable time [11]. Some authors attributed DI to an atrophy of the right lobe of the liver and the associated Chilaiditi syndrome that may lead to diaphragmatic perforation [12].

Many techniques have been described to minimize diaphragmatic thermal injury after RFA procedures. The use of subphrenic artificial ascites or intraabdominal carbon dioxide insufflation has been proposed as a simple and effective method to separate the tumor from the diaphragm and facilitate ultrasonic visualization, without a clinically confirmed heatsink effect [15].

A literature review was performed using the terms “radiofrequency ablation”, “RFA”, “diaphragmatic hernia”, “diaphragmatic injury”, “hepatocellular carcinoma”, “hepatic tumors” and/or “liver tumors” and searching the title, abstract, and keywords of English literature indexed in the PubMed, Medline, Scopus, and Google Scholar databases. Tab. 2 summarizes the demographics, clinical presentations, and details of RFA and DH of the published 22 cases, to the best of our knowledge till 2021.

Based on our literature review, DH after RFA can affect both genders. The presentation is diverse as it may present with dyspnea, pleurisy, abdominal or chest pain, referred shoulder pain, and intestinal obstruction. DH may also present by its complications such as strangulation, respiratory distress, and shock. The presentation may be confusing due to the general condition and comorbidities. The most commonly herniated organ is the right colon. Typically, its presentation is delayed as the DI gradually increases in size causing related symptoms. The duration between RFA and DH has been reported as ranging from one month to three years [18,19,25].

The diagnosis mainly depends on the imaging findings. CT is the mainstay imaging modality in all previously-reported cases. It can show the bowel herniated into the chest as well as other findings such as ascites and pleural effusion. Initial images may show diaphragmatic thickening, fibrosis, and/or localized collection as well as significant pleural effusion. Pleural effusion may arise from ascites that finds its way to the thoracic cavity through a small unnoticed DI (Tab. 2).

It is crucial to differentiate between DH and Chilaiditi sign, seen in up to 22% of cirrhotic patients, owing to the transposition of the large intestine above the shrunken cirrhotic liver within the abdominal cavity. It is not uncommon that DH is misinterpreted as Chilaiditi sign. Moreover, DH may occur with Chilaiditi syndrome. Some authors reported the use of thoracoscopy with or without laparoscopy for the diagnosis and further management of DI in cases of uncertain imaging [13].

Surgical management of DH after RFA is the standard of care and is usually considered an emergency procedure. However, some reported cases were managed non-operatively. The laparoscopic approach has been reported in some cases and depends mainly on the patient’s condition, local expertise, and setting [2].

The interesting point in our case is the short duration between the RFA procedure and its presentation; only four months, which is the second shortest interval in the literature. Such an early presentation may be attributed to a relatively higher thermal damage during the RFA as well as the patient’s extremely poor liver function. The patient presented with intestinal obstruction and shock and his CT scan revealed a huge diaphragmatic hernia containing the terminal ileum with closed-loop intestinal obstruction and mediastinal shift. He underwent RFA four months back for a 3.7cm HCC tumor located in segment VIII. His Child-Pugh score was B. He underwent an emergency exploratory laparotomy with resection of the strangulated terminal ileum, ileostomy, and repair of DI. Eventually, he was discharged home in a satisfactory condition on the seventh postoperative day with uneventful follow-up visits for three months.

CONCLUSION

Radiofrequency ablation is an effective modality for the management of primary and secondary liver tumors. Despite its safety, some complications may happen owing to its thermal effect and the associated patient’s general condition. Many techniques have been described to decrease its thermal injury. Diaphragmatic hernia is a rare complication after RFA. Its clinical presentation may be confusing and it may occur as early as one month after RFA. Its diagnosis depends mainly on computed tomography. Emergency surgical management is the standard approach.

Ethics approval: Not applicable for case reports according to the local policies of Alexandria University.

Consent: The patient signed informed consent and it is available upon request.

Conflict of interests

The authors declare that they have not conflict of interest in connection with this paper and that the article has not been published in any other journal, except congress abstracts and clinical guidelines.

Mohammed S. Foula

Department of Surgery,

King Fahd Hospital of the University,

Imam Abdulrahman Bin Faisal University

e-mail: mohamed.foula@gmail.com

e-mail: msfoula@iau.edu.sa