Introduction:

Bochdalek hernia is a congenital posterior lateral diaphragmatic defect, which allows abdominal viscera to herniate into the thorax. Intrathoracic ectopic kidney accounts for 5% of all renal ectopias and its association with congenital diaphragmatic hernia has been reported to have an incidence of only 0.25%. The reported incidence of intrathoracic renal ectopia due to CDH is 0.25%. A right-sided thoracic kidney is much less common due to the location of the liver. This condition is common in males and in 80–90% on the left side.[1,2] We report a case of a female infant who had a right thoracic kidney associated with right Bochdalek hernia.

Case presentation:

Our female infant was born at full-term by uneventful vaginal delivery with a birth weight of 2400 g (Head circumference 35 cm, Total length 50 cm). The prenatal ultrasound showed no pathological result. Baby had uneventful postnatal history and was with mother on breast feeding. However, the newborn attracted attention by mild tachypnoea and failure to thrive noticed on day 20 of life. Baby was referred to us for further management on day 21 of life. Clinical examination revealed mild tachypnoea with 90% saturations on room air. Baby needed oxygen, had decreased air entry on right side. Conventional chest x-ray showed mediastinal shift to the left side and a raised left dome of the diaphragm with gas shadows in the right lung field, suggestive of congenital diaphragmatic hernia (CDH) (figure 1). Echocardiography was normal. Preoperative sonography abdomen revealed herniation of right kidney. To confirm CT with CT angiography to look for vascular supply of both kidneys was done which revealed herniation of small bowel loops along with right kidney in right posterior hemithorax through defect in posterior part of diaphragm. Right renal artery and vein appear stretched (Fig. 2).

Immediately performed surgery demonstrated a true right side posterolateral CDH (Bochdalek type) without hernial sac. The right kidney and adrenal gland, the majority of small intestine were found to be protruding into the right chest cavity (fig. 3). Intestinal malrotation was excluded. After replacement of the organs into the abdominal cavity, the diaphragmatic defect was closed by primary repair. The right kidney was mobilized without difficulty in a near to normal site. Opening the renal fascia, the kidney showed no deformed shape and no abnormal rotation, as well as a normal age-related size and a normal abdominal origin of renal vessels. After primary closure of the abdominal wall, the postoperative course was uneventful, and the patient was discharged on day 30 on exclusive breast feeding. Postoperative ultrasound demonstrated persistent correct position of the right kidney and a normal renal perfusion without any signs of urinary obstruction.

Discussion:

The posterolateral defect in the diaphragm through which abdominal organs might herniate into the thorax was first described by Vincent Alexander Bochdalek, a Czech anatomist in 1848, hence bears his name Bochdalek's hernia. It occurs more frequently on the left side. This is presumably due to the fact that the pleuroperitoneal canal closes earlier on the right side, or due to the narrowing of the right pleuroperitoneal canal by the caudate lobe of the liver.[1,3] It is common in males than in females in the ratio 2:1.[4] In our case it was a female infant with right side CDH. The ectopic kidney is usually pelvic, iliac, abdominal, thoracic, contra lateral, or crossed.[4] Ectopic kidney is slightly common on the left side, in our case it was on right side.[2,5] The intrathoracic location of an ectopic kidney is the rarest with a reported incidence of 5% of all ectopic kidneys.[1] The association of a Bochdalek hernia and intrathoracic renal ectopia is even rarer at 0.25%.The ectopic kidney has been known to be associated with many other defects ranging from acromelic frontonasal dysplasia to Williams syndrome.[5] However there were no other deformities in this patient.

In majority of individuals, the thoracic kidney is benign and asymptomatic as in our case. It is most often detected incidentally on chest imaging or at the time of thoracotomy for a suspected mediastinal tumor.[6] In such patients the symptoms and X-ray picture might be easily confused for pleuritis, pulmonary tuberculosis, or pneumothorax.[1,7] Chest radiographs are not appropriate, CT scan and MRI would be better for diagnosing diaphragm defects.[8] Intra-venous pyelography or renal scintigraphy usually clarifies the diagnosis. As such an incidentally detected intrathoracic kidney which is asymptomatic does not require any active intervention. Its clinical significance lies in its potential to be confused as a pathological thoracic mass leading to its erroneous excision.[9] Thus Early- and late-presenting CDH may lead to different clinical presentation. Respiratory symptoms seem to be associated more with early CDH and gastrointestinal symptoms with late-presenting CDH.[10] In our patient, tachypnoea associated with failure to thrive was reported. Diagnosis of both these conditions thoracic ectopic kidney and Bochdalek hernia can be reached if and only if there is a high degree of suspicion on the part of the treating physician.

In conclusion, CDH is an emergency in delivery room. Right side CDH has poor prognosis compared to left. In present case, silent tachypnoea was apresentation of this rare anatomy of right side CDH with intrathoracic kidney.