Congenital Posterolateral Diaphragmatic Hernia

Trejo-Scorza E, Medina-González L, Trejo-Scorza CJ, Alvarado Sanavria JM, Lacoa J. Congenital posterolateral diaphragmatic hernia with intrathoracic kidney. Report of a neonatal case. (Versión resumida en ingles de trabajo publicado Rev Obstet Ginecol Venez 2002;62(3):219-224). E-mail: [email protected]. SUMMARY We report a case of a newborn with a left congenital diaphragmatic hernia and an associated ipsilateral ectopic kidney located within the thorax but in an extrapleural location. The diaphragmatic defect was surgically repaired and the kidney left in its ectopic position. After a 5-year follow up, the child remains asymptomatic with adequate pulmonary and renal function. Key words: congenital diaphragmatic hernia, intrathoracic kidney.

INTRODUCTION A congenital posterolateral diaphragmatic hernia (CDH) is the passing of abdominal viscera into the thoracic cavity through a persistent pleuroperitoneal canal. Described in 1948 by Bochdalek (1), CDH is the most frequent diaphragmatic defect in neonates, and presents clinically with perinatal or postnatal respiratory distress. Approximately 40% of the liveborn neonates with CDH have associated anomalies, 23% of which are genitourinary (2). Renal dysplasia, hydronephrosis and renal agenesis are the most frequent urinary anomalies associated with CDH (3,4). Thoracic renal ectopia is very rare and only 131 cases have been reported in the worldwide literature until 1986 (5). The association of thoracic kidney with CDH is less than 0,25% (5,6). We found three case reports of thoracic kidneys in the Venezuelan medical literature, two left and one right, in an adult and two children respectively, only one associated with a congenital diaphragmatic hernia

(7-9). We discuss the clinical, radiological, surgical and functional findings of a neonate with a left CDH and associated intrathoracic kidney, followed up for five years.

CASE REPORT Due to fetal-pelvic disproportion, persistent transverse position and premature rupture of membranes, a full term male neonate of 3300 g was delivered by cesarean section. The mother was a primipara 26-year-old white woman. Pregnancy was controlled and complicated with polihydramnios. At 3 hours post partum, the neonate developped dyspnea with chest retraction; breath sounds were symmetrical and Silverman score of 2 at 3. Respiratory distress was diagnosed and 40% oxygen administered via mask. At 40 hours post partum, the oxygen therapy was gradually reduced, as his breathing improved, and oral feeding was commenced. 10 hours later, the patient redevelopped respiratory distress, with a Silverman score of 4, requiring 100% oxygen via mask. The chest radiograph showed gas-filled bowel loops in the left hemithorax, and mediastinal shift to the right side. (Figure Nº 1). The patient was transferred to the neonatal intensive care unit with a diagnosis of left CDH. Arterial blood gases and blood cultures were sampled, with a pH of 7.35 , PCO2 of 27 mmHg, PO2 of 200 mmHg, EB of -8.6, HCO3¯ of 15 meq/l and saturation of 99.3% with an inspiration oxygen fraction (fiO2) of 1; the blood cultures yielded Klebsiella sp. At the age of 4 days, he underwent laparotomy, demonstrating a left posterolateral diaphragmatic defect of 5 cm in diameter. Stomach, spleen, small and large bowel were found within the left hemithorax and the gut was malrotated. The hypoplastic left lung was approximately 1/3 of its normal size. The left kidney was located within the thorax between parietal pleura and internal chets wall (Fig

Nº 2). After reduction of the herniated organs and a prophylatic appendicectomy, the diaphragmatic defect was repaired, whilst the kidney was left within the thorax due to its extrapleural location. Post intervention, the patient needed respiratory support and inotropes twice, due to bilateral basal atelectasia and signs of septic shock. Repeat blood cultures isolated Enterobacter sp. and budding fungi were found in the urine, treated with appropriate antibiotics and fungicides (amphotericin). The patient was discharged from the hospital in good condition, at the age of 36 days. Post-operative ultrasound and excretory urography demonstrated presence of both kidneys, the left located within the thorax. Bilateral contrast elimination was appropriate and there was no evidence of pelvicalyceal or ureteric dilatation (figures 3 and 4). The child was discharged at 5 years of age with normal pulmonary and renal functions.

DISCUSSION CDH can be associated with other congenital malformations, and those related to herniation of abdominal viscera into the pleural cavity, e.g. pulmonary hypoplasia and intestinal malrotation, are the most frequent. This complex of malformations is considered part of the “CDH-syndrome” (pulmonary hypoplasia, malrotation, patent ductus arteriosus and patent foramen oval). Excluding the malformations of the “CDH-syndrome”, 40% of the liveborn neonates with CDH, have one or more associated anomalies and approximately 23% of these are genitourinary malformations (2). Renal malformations associated with CDH are found in 27% of the autopsy cases (3), the most frequent being renal dysplasia, hydronephrosis and renal agenesis. Mota-Salazar and Trejo-Padilla (4) reported 17 cases of CDH in 24 years (Hospital de Niños “JM de los Ríos”, 1936-1959) and

found one renal malformation (a hydronephrosis), amongst the 12.5%, of non“CDH-syndrome” anomalies. Barba et al (not published), reviewed 31 cases of CDH in 26 years (1960-1985) in the same institution. 6 of these cases (16.7%) had associated non-“CDH-syndrome” anomalies, only one of which was renal (hydronephrosis). Renal ectopias are classified as thoracic, low abdominal, iliac, pelvic or crossed (10). Thoracic renal ectopia is the rarest of all, with about 131 cases reported in the world literature until 1986 and only 50 cases described in children (5). Thoracic kidney represents only 5 percent of all ectopic kidney, and is more common on the left side and in males (5,10). The thoracic kidney is usually asymptomatic and is generally discovered on a chest radiograph showing a convex shadow just above the diaphragm in the lower and posterior zone of the hemithorax (5,11). Furthermore intrathoracic kidneys may be found with nuclear medicine studies (11,12). Excretory urography and computed tomography aid to establish the diagnosis (13,14-15). Four types of intratoracic kidney have been described (5,6): 1.- thoracic renal ectopia with normal development of diaphragm. 2.- thoracic renal ectopia associated with congenital diaphragmatic hernia. 3.- thoracic renal ectopia with diaphragmatic eventration and 4.- thoracic renal ectopia with traumatic rupture of the diaphragm. The association of CDH and intrathoracic kidney is very rare, less than 0,25% (5,6). When the CDH is associated with an intrathoracic kidney, two groups can be distinguished:

a. - In the first group, the intrathoracic kidney is part of the hernial content and can be easily reduced into the abdominal cavity. The cases reported by Ho et al (6) and Hallisey and Caride (15) represent two examples. b. - In the second group, the kidney is located within the thoracic cavity but in an extrapleural location (Fig 2), separated from the hernia by pleura. When the hernia is reduced, the thoracic kidney is seen as an intrathoracic solid beanshaped mass lying posterior to the parietal pleura as shown in the case presented by the autor. The extrapleural thoracic kidney may or may not be accompanied by a defect or anomaly of the diaphragmatic muscle, since its thoracic location is the result of a delayed mesonephric involution, rather than the result of a diaphragmatic defect (16). The typical characteristics of an intrapleural thoracic kidney are a blood supply from a lengthened renal artery with a normal anatomical origin (15, 17) and an ipsilateral diaphragmatic defect with the kidney forming part of the hernia and being readily reducible into the abdominal cavity. Therefore the intrathoracic location of the kidney results from a defect in the closure of the pleuroperitoneal canal, easily demonstrated with fluoroscopy, where the ectopic kidney is seen to be moving with respiration (15). On the other hand, the characteristics of an extrapleural thoracic kidney are a blood supply from a renal artery with an abnormal high origin (5,15,18), renal malrotation with an anteriorly facing hilus and an unusually long ureter; a diaphragmatic defect may or may not be present and, more importantly, the ectopic kidney is separated from the hernia by parietal pleura and can not be reduced into the abdomen due to the abnormally high origin of its supplying artery. In this case fluoroscopy with fail to show respiratory changes of

the position of that ectopic kidney. Therefore, extrapleural intrathoracic renal ectopia results from a delayed mesonephric involution (5,16). Intrathoracic kidneys rarely become symptomatic and renal disease may exist (21,23), if chest pain or arterial hypertension develop (15,19-22). SIADH (syndrome of inappropiate antidiuretic hormone) was the presenting symptome in a patient with an intrathoracic kidney and ipsilateral renal cell carcinoma (21). Occasionally, the intrathoracic kidney may be accompanied by other congenital renal anomalies (6,16,24-26), and duplication of the renal pelvis with incomplete duplication of ureter seems to be the most frequent genitourinary anomaly associated with intrathoracic kidney (6,24). In every patient with a chest radiograph demonstrating a convex shadow above the diaphragm, an intrathoracic kidney must be included as a possible differential diagnosis. The diagnosis of an intrathoracic kidney is made by an excretory urography or computed tomography. Excretory urography not only allows to establish the diagnosis (22), but may also demonstrate indirect evidence of renal artery stenosis (23), or may show other renal anomalies (6, 24). These studies should be carefully evaluated to discard the existence of either congenital or acquired pathologies in both the ectopic kidney and contralateral kidney (5,6,13,19,23,24). Costal and vertebral anomalies accompanying an intrathoracic kidney, point towards a congenital etiology of the intrathoracic kidney (16,19). Once the diagnosis of intrathoracic kidney is established, it is necessary to determine whether the ectopic kidney is intra- or extrapleural as the intrathoracic kidney of intrapleural localization is always accompanied by a diaphragmatic defect requiring surgical treatment, whereas an intrathoracic kidney of extrapleural localization does not require intervention. Ultrasound, computed tomography and / or fluoroscopy are suitable investigations, as ultrasound allows visualization of an

intact diaphragm (2), computed tomography is able to demonstrate the presence of a diaphragmatic defect (15,27) and fluoroscopy allows to assess respiratory changes in the renal position (15).

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11. De Castro FJ, Schumacher H. Asymptomatic thoracic kidney. Clin Pediatr 1969;8(5):279-280. 12. Toba M, Fuguchi K, Hayashida K, Takeda Y, Fukushima K. Intrathoracic mass simulated by ectopic kidney. Clin Nucl Med 2000;25(4):289-90. 13. Williams RR, Jeans WD. Thoracic ectopic kidney in an adult. Scand J Urol Nephrol 1996;30:133-134. 14. Louzir B, Beji M, Chtourou S, Fajraoui N, el-Mekki S, Jouini S, Mnif E, Slim R, Daghfous J. Diagnosis of an opacity at the lung base: intrathoracic kidney. Rev Mal Respir 1999;16(2):207-209. 15. Hallisey MJ, Caride VJ. Single perfusion defect secondary to intrathoracic kidney. Clin Nucl Med 1990;15:523-524. 16. Angulo JC, Lopez JI, Vilanova Juan R, Flores N. Intrathoracic kidney and vertebral fusion: a model of combined misdevelopment. J Urol 1992;147:1351-1353. 17. Macian AM, Gonzálvez Pinera J, Andujar Cairo M, Ruiz Carazo E, Casado Moragón L. Riñón intratorácico en la infancia: a propósito de un caso. An Esp Pediatr 1993;38(5):455-457. 18. Kageyama Y, Kihara K, Oshima H. Intrathoracic herniation of the kidney. Urology 2000;55:143-144. 19. Vásquez J, Lupi Herrera E, Kasep J. Riñón derecho con localización intratorácica de causa congénita. Arch Inst Cardiol Mex 1984;54:377-379. 20. Mikoloski VS. Ectopic thoracic kidney. JAMA 1971;215(7):1158. 21. Kubricht WS, Henderson RJ, Bundrick WS, Venable DD, Eastham JA. Renal cell carcinoma in an intrathoracic kidney: radiographic findings and surgical considerations. South Med J 1999;92(6):628-629. 9

22. Kirshenbaum AS, Puri HC, Rama Rao B. Congenital intrathoracic kidney. J Urol 1981; 125(3):412-3. 23. Palmer JM. Ectopic thoracic kidney. JAMA 1971;217(8):1108. 24. Burioka N, Tomita K, Sasaki T. A case of left intrathoracic kidney with renal anomalies. Nihon Kyobu Shikkan Gakkai Zasshi 1991;27(9):921-924. 25. Stein JP, Kurzrock EA, Freeman JA, Esrig D, Ginsberg DA, Grossfeld GD, Hardy BE. Right intrathoracic renal ectopia: a case report and review of the literature. Tech Urol 1999;5(3):166-168. 26. Fusonie D, Molnar W. Anomalous pulmonary venous return, pulmonary sequestration, bronchial atresia, aplastic right upper lobe, pericardial defect and intrathoracic kidney. An unusual complex of congenital anomalies in one patient. Am J Roentgenol Radium Ther Nucl Med 1966;97(2):350-354. 27. Súarez S, de JY. Acquired intrathoracic kidney. P R Health Sci J 1998;17(3):289-91.

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FIGURES Figure 1: Chest radiograph showing gas-filled bowel loops in the left hemithorax, and mediastinal shift to the right. A convex shadow (black arrow) is seen in the left hemithorax.

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Figure 2a: Left parasagital section of the trunk demonstrating a posterolateral diaphragmatic defect and the left intrathoracic kidney covered by parietal pleura.

Figure 2b: Parasagital section of the trunk demonstrating a left posterolateral diaphragmatic defect and left intrathoracic kidney.

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Figure 3a and 3b: Post-operative excretory urography demonstrating a normally located right kidney, and a left supradiaphragmatic kidney (white arrow)

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Acknowledgements I am grateful To Drs. Masahiro Toba, Yukio Kageyama, Michael J. Hallisey, Vicente J. Caride, A. Marco Macian who kindly sent me photocopies and copy reprint of published manuscripts, difficult to get in my country. To Dr. Oscar Agüero who revised and corrected this manuscript. To my sons Ezequiel and Victor, who helped me to translate this manuscript to the English language. To Dr. Marcel Strauss who revised and corrected the translation to the English language.

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