Figure 1. Axial CT image at presentation demonstrating intrathoracic kidney with severe hydronephrosis due to compression of the ureteropelvic junction by the diaphragmatic crus.

Figure 2. Coronal CT image after percutaneous nephrostomy placement prior to hernia repair and nephropexy.

Figure 3. Postoperative coronal CT image with intra-abdominal kidney.

A 58-year-old male presented to the emergency department with severe left flank pain that had been worsening over the last 5 months. The pain radiated to his left upper quadrant and left anterior ribs and was associated with significant nausea and vomiting. He had a prior history of a congenital diaphragmatic hernia repaired as an infant, without other significant medical history. His lab work showed a creatinine of 1.25 mg/dL without a known baseline. Imaging in the emergency department revealed a left sided Bochdalek hernia, a congenital defect of the diaphragm through which abdominal organs can herniate into the thoracic cavity. In this patient’s case, nearly his entire left kidney was found to be intrathoracic with compression of his ureteropelvic junction by the left diaphragmatic crus, causing severe hydronephrosis (Figures 1 and 2). Given these findings, the decision was made to place a left percutaneous nephrostomy tube for immediate decompression, which resulted in near immediate pain relief. Antegrade pyelogram showed retention of contrast without drainage at the ureteropelvic junction, confirming obstruction.

The hernia was ultimately repaired with a transabdominal, robotic downward nephropexy (Figure 3). Robotic trocars were placed in the upper left quadrant after laparoscopic access. Very few adhesions were seen and the lower pole of the kidney was identified within the hernia sac. Circumferential mobilization of the kidney and the hilum within the hernia sac was performed and the kidney was fixated to the psoas fascia. Given the redundant ureter and narrowing of the ureteropelvic junction, a dismembered pyeloplasty was performed with stent placement. The case was performed in conjunction with thoracic surgery, which robotically repaired the Bochdalek hernia with mesh through the same trocars. The patient recovered well after surgery and was discharged home on postoperative day 3.

Bochdalek hernias are an incredibly rare condition with an incidence of only 0.17%. They occur due to failure of closure of the posterolateral foramina of the diaphragm and various abdominal organs can herniate into the thoracic cavity, including the kidney, liver, colon, spleen, and stomach. They occur on the left side of the diaphragm 85% of the time, on the right side of the abdomen in roughly 13% of cases, and are bilateral in only 3%-6% of cases.¹ When examining all types of ectopic kidneys, intrathoracic kidney is the rarest type of ectopia, occurring in less than 5% of cases.² Many Bochdalek hernias are identified early in infancy as they can result in pulmonary complications and respiratory distress. However, in adults they can be found incidentally or can present symptomatically with abdominal or chest pain or dyspnea.³ If the patient is asymptomatic, the hernia can be managed conservatively with labs and imaging to monitor for progression and surgical intervention is not necessarily warranted.⁴ In one review of 33 patients with Bochdalek hernias, only 2 patients had documented impaired renal function, 6 cases had normal renal function, and 25 reports did not comment on renal function.⁵ In the same series, surgical repair was found to be uncommon. Diaphragmatic repairs were performed in 12% of patients, partial nephrectomy occurred in 3% of patients, and emergency laparotomy and thoracotomy were performed in 3% of cases. Minimally invasive surgical intervention specifically for urinary obstruction is even rarer, with a case report in 2019 noting that there had only been 3 reported cases of Bochdalek hernias leading to obstruction and their case was the first case of obstruction resolved by laparoscopy.⁶

Overall, data on Bochdalek hernias are rare and mostly limited to case reports and case series due to the extremely low incidence of the condition. Our patient represents a very small percentage of patients presenting with urinary obstruction for which surgical repair was indicated and successfully performed.