Congenital peritoneo-pericardial hernia in a 4 years-old child: Case report of a rare type of congenital diaphragmatic hernia

Abstract

Congenital peritoneo-pericardial Hernia (CPPDH) occurs when a defect in the central tendon of the diaphragm allows communication between the peritoneal and pericardial cavities, leading to herniation of intra-abdominal organs into the pericardial cavity. It is an extremely rare form of congenital diaphragmatic hernia with only a few reported cases in the literature. We report a case of congenital peritoneo-pericardial hernia diagnosed in a 4-year-old female child after she presented with fast breathing and intermittent cough. The diagnosis was suspected during echocardiography,when a solid mass having similar echogenicity to the liver was seen in the pericardial cavity. Computed tomography (CT) scan demonstrated a central diaphragmatic defect and herniation of the left liver lobe and the stomach into the pericardial cavity. Currently, surgery is the only option of management, and a correct diagnosis is usually not made prior to surgery. Our report highlights the crucial imaging findings helpful in the preoperative diagnosis, and also the importance of considering CPPDH as a differential diagnosis for an unusual intra-pericardial lesion discovered during echocardiography.

Introduction

Congenital peritoneo-pericardial hernia (CPPDH) is a rare form of diaphragmatic hernia resulting in communication between the peritoneal and pericardial cavities. Since it was first reported in 1903 by DeCardinal et al. [1,2], only a few cases have been reported in the literature. The presentation can vary from respiratory distress and cyanosis to incidentally discovered asymptomatic cases. It is difficult to diagnose CPPDH preoperatively. It should be considered as a differential diagnosis when an unusual intra-pericardial lesion is discovered during imaging and in cases of diaphragmatic hernia through the space of Morgagni. Radiograph, ultrasound, and CT scan play vital roles in suspecting and then eventually diagnosing this rare abnormality by demonstrating acentral diaphragmatic defect and herniation of abdominal organs into the pericardium. Cases of CPPDH are treated by surgically repairing the defect [3,4]. Our report highlights the crucial imaging findings helpful in the preoperative diagnosis of CPPDH.

Case presentation

A 4-year-old Ethiopian female child was brought to the outpatient clinic with intermittent cough and fast breathing of 1 month's duration. She had episodes of similar illness since early childhood, for which she was treated in a local health centre with an antibiotic. She has no history of trauma. The prenatal period was uneventful. She is the third child of her parents, and all her elders have no known medical illness. On physical examination, she was tachypnic (respiratory rate was 42 per minute). Other vital signs were in normal range. The height-for-age (HFA) z-score was below 2 standard deviations (SD) of the median World Health Organization (WHO) standard, indicating stunting. But she has no cyanosis, no added sound on chest auscultation, and no murmur or gallop identified on cardiac examination. No chest deformity was seen.

With suspicion of congenital heart disease, echocardiography was done. On echocardiography, an echogenic solid tissue and a fluid-filled loop were seen on the right side within the pericardial cavity, displacing the myocardium of the right cardiac chambers to the left side. This solid tissue has similar echogenicity to liver parenchyma and continuity with the left liver lobe inferiorly. No shunting defect is seen. The great vessel anatomy was normal. There was also mild pericardial fluid collection seen (Figs. 1A-C). With suspicion of peritoneo-pericardial hernia, Contrast Enhanced Computed Tomography (CECT) of the abdomen and chest was done.

Fig. 1.

(A-C) Ultrasound images (subcostal views) showing the herniated left lobe of liver ad stomach in the pericardial cavity. The right cardiac chambers are compressed by the mass effect. There is also mild anechoic pericardial fluid collection seen.

On the CT, there is a midline diaphragmatic defect measuring 2.25cm (anteroposterior) x 3.7cm (medio-lateral). A small segment of the diaphragm, measuring 4mm in anteroposterior dimension, is visible between the anterior margin of the defect and the anterior thoracic wall. A solid tissue, which is continuous with the left liver lobe and similar in density and enhancement to the liver, is seen inside the right side of the pericardial cavity. Medial to this, the body of the stomach is also seen in the pericardial cavity, containing some fluid and air. Both organs are seen passing from the abdomen into the pericardial cavity through the central diaphragmatic defect. The herniated contents are covered and sharply demarcated laterally by the pericardium. The right atrium and right ventricle are compressed and displaced to the left side and superiorly by the mass effect (Figs. 2A-H). The lungs are normal bilaterally. No shunting defect is seen. The great vessels of the heart are also normal. With a working diagnosis of congenital peritoneo-pericardial diaphragmatic hernia, her parents were advised about the need for surgical intervention. She is currently on regular outpatient follow-up, awaiting possible surgery in another facility capable of doing the procedure.

Fig. 2.

(A-D) [axial precontrast (A, C and D) and postcontrast (B) images. The image in (A) is at the level of the yellow line seen in (E)]: show a herniated solid mass in the pericardial cavity (Green arrows) having continuity with the liver (as seen in (D)) and also similar enhancement to it(as seen in (B) and (E)). The intra-pericardial segment of theliver is outlined by the red dotted lines in (D).(H)[a coronal precontrast CT image at the level of the red line seen in (A)]: also depicts the liver (as outlined by the red dotted lines) and the herniated left lobe segments (indicated by Green arrow).The body of the stomach (Blue arrows in C and D), filled with gas and fluid, is also seen medial to the herniated liver in the pericardial cavity.(E)[sagittal postcontrast CT image at the level of the line seen in (B)]and (G) [a coronal lung window CT image at the level of the line seen in (C)]: depict the anterior midline defect in the diaphragm through which the stomach herniated in to the chest (yellow arrow in E and green line in (H)). (F): [another sagittal postcontrast CT image] depicting a small remnant portion in the anterior diaphragm anterior to the central defect (green arrow in (F)).The heart is seen displaced to the left side and superiorly with mass effect on the right side chambers (Green arrow in (B) and purple arrow in (E)).

Discussion

Peritoneo-pericardial diaphragmatic hernia (PPDH) is a rare type of diaphragmatic hernia where intra-abdominal contents herniate through a midline defect in the diaphragm into the pericardial cavity. A diaphragmatic defect involving the central tendon leads to the peritoneo-pericardial communication [5,1]. It is often acquired but can rarely be congenital. Cases of acquired PPDH are mostly due to trauma or iatrogenic injuries. Congenital peritoneo-pericardial diaphragmatic hernia (CPPDH) is extremely rare. Only a few cases of CPPDH are reported in the literature [[6], [7], [8]]. Its incidence is 1%-6% of all congenital diaphragmatic hernias, which by itself occurs in 0.08-0.45 per 1,000 live births [6,8]. It can occur isolated but is often associated with other anomalies like ectopiacordis, atrial septal defect, and bicuspid aortic valve, or even as part of the typical pentalogy of Cantrell [9]. In our case, no other associated anomaly was detected.

The central tendon is a central anterior aponeurotic portion of the diaphragm that blends with the pericardium above. Embryologically, it develops from the septum transversum, a mesodermal sheet that separates the primitive coelomic cavity into thoracic and abdominal cavities and contributes to the formation of the diaphragm, falciform ligament, liver, and pericardium. Central tendon defect can develop from a partially defective septum transversum or rupture of the weakened septumby the rapid growth of the liver into it during the 4^th and 5^th week of gestation [3]. The most common herniated organs are the transverse colon (49.4%) and the greater omentum (48.2%), followed by small bowel (37.6%), stomach (36.5%), and liver (10.6%) [4]. In our patient, the involved organs are the liver and the stomach.

Newborns with CPPDH present with respiratory distress and respiratory failure due to bilateral pulmonary hypoplasia. Venous congestion in the incarcerated hepatic segments could lead to gradual transudative pericardial fluid accumulation and eventually pericardial tamponade. In adults, symptoms like dyspnea, cyanosis, palpitation, and chest pain are commonly reported. Presentation with acute abdomen occurs upon incarceration of the gastrointestinal tract. The diagnosis can also be made incidentally [[3], [4], [5]].

Imaging plays an important role in the diagnosis of CPPDH. On chest radiographs, intra-thoracic added density or gas-filled loops above the diaphragm, obscuring the cardiac border, may be seen abnormally distending the pericardium. Abdominal radiographs can show the nonvisualization of the liver shadow to the left of the spine, also called “liver cut-off sign”. Widened mediastinum due to pericardial effusion is another suggestive evidence on x-ray [5,9]. In our case, X-ray was not done because CPPDH was suspected on echo evaluation, and CT was done to settle the diagnosis. But the scout imageon the CT similarly demonstrates mediastinal widening, gastric gas bubble shadow above the diaphragm in the midline, and liver cut-off sign (see Fig. 3). The use of barium for the diagnosis is currently not recommended. The procedure carries a high risk of bowel obstruction and cardiac tamponade due to the introduction of fluid and air under pressure into the herniated viscus [1,10].

Fig. 3.

Scout image showing gastric gas shadow above the level of the diaphragm in the midline and absent liver shadow to the left side of the vertebra (liver cut off sign). Note also, the mediastinum (cardiac contour) is also widened.

On ultrasound and CT scan, liver protrusion into the pericardium can be suggested by the presence of a solid intra-pericardial mass in continuity with the liver, demonstrating similar density and enhancement as the liver and by recognition of hepatic vessels within the mass [3,11]. Another evidence of PPDH on CT is the visualization of intra-peritoneal fat in continuity with the fat in the mediastinum, and also the presence of coils of bowel loop in the mediastinum laterally covered by the pericardium [1].

Intra-pericardial Morgagni Hernia, an extremely rare form of Morgagni hernia with only a few reported cases, is a competing differential diagnosis in our case. In such cases, the diaphragmatic defect is seen immediately posterior to the anterior thoracic wall, while there is some diaphragmatic tissue present anterior to the defect in cases of CPPDH, which is also seen in our patient’s CT finding [11]. Surgery is currently the only recommended option for management. When the preoperative diagnosis is clear, an abdominal approach to repair the diaphragmatic defect with a prosthetic patch is preferred [3].

In conclusion, we have presented an additional report on a rare case of congenital intra-pericardial herniation of the liver with emphasis on the imaging features. As this condition is amenable to surgical correction, prompt diagnosis and intervention are crucial. Though both CECT and ultrasound are confirmatory, ultrasound has the advantage of being dynamic and noninvasive with no radiation exposure. Therefore, CPPDH must be borne in mind by clinicians while evaluating an infant or a child presenting clinically with respiratory distress and an unusual intra-pericardial mass on echocardiography, following which CT must be performedto rapidly arrive at the final diagnosis.

Ethical considerations

The parents, who are legal guardians of the patient has provided consent for the publication of the information in this article. It was ensured that any personal information that could identify the patient would be kept anonymous at all times.

Patient consent

After a thorough explanation of the case report and its publication process, written informed consent for the inclusion of their medical information was obtained from the patient’s legal guardians (the parents). This ensures their understanding and authorization for the anonymized presentation of this case for educational purposes.