Retroperitoneal leakage causing ultrafiltration failure during continuous ambulatory peritoneal dialysis: a case report and literature review

Abstract

Background

Peritoneal dialysis (PD) is associated with various complications, and the leakage of dialysate can lead to the discontinuation of PD. Retroperitoneal leakage (RPL) can be diagnosed on the basis of dialysate leakage, and, because there are few reports of this complication, clinicians often have an incomplete understanding of its diagnosis, causes, and treatment options.

Case presentation

A 59-year-old man who underwent continuous ambulatory peritoneal dialysis (CAPD) 1 year prior to admission was referred to our department owing to right-sided abdominal swelling and persistent ultrafiltration failure (UFF). No abnormalities were observed at the catheter exit or tunnel site. Plain abdominal computed tomography (CT) revealed that the catheter was not malpositioned and that fluid had accumulated in the right retroperitoneal space, causing edema in the abdominal wall. If UFF persists, CAPD must be discontinued and patients must be hospitalized. Subsequently, computed tomographic peritoneography (CTP) following the instillation of 2 L of dialysate with contrast agent revealed clear progression of the contrast agent into the right retroperitoneal space, confirming RPL owing to retroperitoneal injury at the dorsal aspect of the ascending colon.

Conclusions

As a rare complication of PD, RPL causes few local symptoms and is therefore often unrecognized, resulting in UFF. Thus, CTP is useful for diagnosing RPL in the presence of dialysate leakage. However, if we were fully educated on RPL, we could have diagnosed it when plain CT scans were performed.

Background

Peritoneal dialysis (PD) is widely performed worldwide as a renal replacement therapy (RRT) for end-stage kidney disease (ESKD). It stabilizes patients’ hemodynamics during treatment and can be performed at home. However, various complications exist. Infectious complications, such as peritonitis and catheter exit site or tunnel site infections, are most common. Additionally, noninfectious complications, such as ultrafiltration failure (UFF), are significant clinical issues leading to fluid overload and uremia, potentially resulting in the discontinuation of PD [1]. The causes of UFF include mechanical problems with the peritoneal catheter, dialysate leakage and peritoneal membrane dysfunction. Retroperitoneal leakage (RPL) is a rare type of dialysate leakage and is often difficult to diagnose. Here, we report a case of UFF accompanied by RPL in a patient undergoing continuous ambulatory peritoneal dialysis (CAPD), along with a literature review.

Case presentation

The patient was a 59-year-old male with ESKD owing to nephrosclerosis who had been on CAPD for one year. He had undergone right inguinal hernia repair at 4 years old and had no history of any other abdominal surgeries. The peritoneal catheter was inserted surgically using a paramedian approach and a swan neck PD catheter (JB-5A; Hayashidera, Ishikawa, Japan).The catheter tip was successfully positioned in the Douglas pouch. There were no issues with catheter malposition or drainage, and he was treated as an outpatient at a dialysis clinic. The CAPD prescription consisted of 1.5 L of icodextrin dialysate at 6 a.m., 2 L of 1.5% dextrose dialysate at 6 p.m. and 2 L of 2.5% dextrose dialysate at 11 p.m., with three daily bag exchanges. The patient noticed swelling on the right side of his abdomen approximately 4 weeks before referral to our hospital. As a result, he was referred from the clinic due to UFF. He had a height of 173 cm, weight of 80 kg and body mass index of 26.9 kg/m² and presented with edema in his lower limbs and borderline indistinct swelling on the right side of his abdomen. There was no redness or exudate at the peritoneal catheter exit site (Fig. 1). Abdominal plain computed tomography (CT) revealed that the catheter was not malpositioned and that fluid had accumulated in the right retroperitoneal space. An increase in fat tissue density was also observed, suggesting edema in the subcutaneous and muscle layers of the right abdominal wall (Fig. 2). The swelling on the right side of the patient’s abdomen did not worsen, but he was admitted to our hospital because of continued UFF. Chest radiography at admission revealed that both the right and left diaphragms were higher than before the initiation of CAPD, with intestinal gas shadows observed below the right diaphragm (Chilaiditi sign) (Fig. 3). On the same day, the patient underwent computed tomographic peritoneography (CTP) and 2 L of 1.5% dextrose peritoneal dialysate was mixed aseptically with 150 mL of contrast agent (Omnipaque 300; GE HealthCare Pharma, Tokyo, Japan) and then instilled into the peritoneal cavity 1 h before imaging. The patient was asked to ambulate for approximately 30 min following instillation. CTP images revealed that the contrast agent had progressed into the right retroperitoneal space along the pararenal fat (Fig. 4B, C). RPL due to retroperitoneal injury at the dorsal aspect of the ascending colon was diagnosed. Additionally, a small umbilical hernia (Fig. 4B) and the Chilaiditi sign (small intestine and large bowel interposed between the anterior surface of the right hepatic lobe and the right diaphragm) were observed (Fig. 4A, C). Following imaging, the dialysate containing contrast agent was drained, and 1.5 L of 1.5% dextrose dialysate was instilled into the peritoneal cavity to halt dialysate retention. Shared decision-making regarding changes in RRT led to the decision to convert to permanent hemodialysis (HD). On the day after admission, the patient underwent PD catheter removal and arteriovenous fistula creation. Then, on postoperative day 3, he was discharged with instructions for HD. He has since been undergoing nocturnal HD at the dialysis clinic (Fig. 5).

Fig. 1

Physical examination at referral. Borderline indistinct swelling was noted on the right side of the abdomen (arrowheads). There was no redness or exudate at the peritoneal catheter exit site (arrow)

Fig. 2

Abdominal plain computed tomography image at referral. The arrows show fluid accumulation in the right retroperitoneal space. The arrowheads show increased fat tissue density, suggesting edema in the subcutaneous and muscle layers of the right abdominal wall

Fig. 3

Chest radiography. A Before the initiation of CAPD. B At admission. B Both the right and the left diaphragms were higher compared with that in A, with intestinal gas shadows observed below the right diaphragm (Chilaiditi sign)

Fig. 4

Computed tomographic peritoneography images at admission. A, B Axial image and C sagittal image showing the contrast agent progressing into the right retroperitoneal space along the pararenal fat (black arrows). A small umbilical hernia (white arrowhead) and the Chilaiditi sign, in which the small intestine and large bowel are interposed between the anterior surface of the right hepatic lobe and the right diaphragm (white arrows), were noted

Fig. 5

Clinical course before and after referral to our hospital. Changes in the daily ultrafiltration volume and body weight. UF, ultrafiltration

Literature review

To our knowledge, RPL was first reported by Prokesch et al. [2] from Austria in 2000 (Table 1). In total, 20 patients with complications of CAPD underwent magnetic resonance (MR) peritoneography: MR imaging after the instillation of dialysate with a gadolinium-based contrast agent. This procedure revealed abnormalities in 13 patients, 6 of whom (46.2%) were diagnosed with RPL and also displayed ultrafiltration (UF) problems [2]. Arbeiter et al. [3] at the same institution described a case of RPL in a child on CAPD. The dialysis regimen was changed to tidal PD with shortened dwell times. The patients still had to be switched to HD because of persistent UFF. Finally, the patient underwent cadaveric transplantation 1 month later. Lam et al. [4] from Hong Kong reported three cases of RPL diagnosed with CTP. They reported that RPL was difficult to detect clinically because of the lack of local signs on physical examination. Thereafter, they reported that, over a 5-year period, 36 of 743 patients with PD developed UFF, 23 of whom had RPL; the incidence of RPL was 3%, and it was not a rare complication of PD [5]. Additionally, Cheung et al. [6] at the same institution reported RPL in 13 of 28 patients (46.4%) with UFF who underwent CTP two or more times for follow-up. RPL may occur due to increased intra-abdominal pressure associated with activities, such as walking, coughing, straining, or large volumes of dialysate infusion. Furthermore, a history of hernia or pleuroperitoneal communication has been identified as a risk factor for RPL [5]. Most patients recover and can resume CAPD after switching from CAPD to intermittent peritoneal dialysis (IPD) via a cycler; IPD was performed twice a week with 2 L of dialysate in hourly cycles for a total duration of 8 weeks. During IPD, patients are advised to remain supine if possible to avoid increasing intra-abdominal pressure [4,5,6]. Oka et al. [7] from Japan described a patient with RPL who presented with lower abdominal distention and scrotal edema. They temporarily switched to HD while waiting for the damaged peritoneum to heal. After a 4-week rest period, PD was gradually resumed and the nocturnal IPD prescription was decreased (1.6 L for four cycles) to avoid increasing intra-abdominal pressure, and then eventually increased to 2 L for four cycles. The patient was then converted to combination therapy with PD and HD and remained relapse-free for 4 years [7]. No other cases from other countries or regions were reported, and the incidence rate of RPL remains unknown.

Table 1 Review of literature on retroperitoneal leakage

Discussion and conclusions

This patient presented with UFF and indistinct swelling on the right side of the abdomen where the CAPD catheter was inserted, raising suspicion of dialysate leakage. The average daily UF volume was 709 mL/day 6–7 weeks before referral, 146 mL/day 2–3 weeks before referral, and then further decreased thereafter. The patient gained approximately 4 kg, making CAPD continuation difficult (Fig. 5). Dialysate leakage is defined not only as leakage around the PD catheter but also as loss of dialysate from the peritoneal cavity, excluding loss from the catheter lumen [8]. Although the plain abdominal CT scan at the time of referral to our institution revealed possible dialysate leakage into the right retroperitoneal space, a definitive diagnosis was not possible. CTP was performed on the 9th day after referral. CTP images confirmed the diagnosis of RPL, revealing the progression of contrast medium into the retroperitoneal space along the right pararenal fat. Furthermore, the slow-seeping dialysate trapped in the intermuscular and subcutaneous fat tissues appeared to be the main cause of swelling in the right abdominal wall and UFF. A large amount of dialysate had accumulated in the perihepatic space owing to an intervening small intestine and large bowel loop between the liver and diaphragm; however, upright chest radiography revealed intestinal gas under the right diaphragm, indicating that the dialysate in the perihepatic space was not trapped and unlikely to cause UFF. The small umbilical hernia also did not appear to contribute to UFF.

One reason for the difficulty in diagnosing RPL is the lack of significant physical findings. In this case, although the patient presented with swelling on the right side of his abdomen, it was not localized, as in the case of a hernia, but rather diffuse, making it difficult to ascertain the cause. Radiological examination is necessary for diagnosis. CTP can be used to accurately identify dialysate leaks, including pericatheter leakage, hernias, and pleuroperitoneal communication [9, 10], as well as RPL. In this case, 2 L of peritoneal dialysate was mixed with 150 mL of nonionic contrast agent containing 300 mg of iodine per mL and instilled aseptically. Moreover, 100 mL of contrast agent may be sufficient for adequate contrast [9, 10]. In patients with PD with residual renal function, intraperitoneal administration of contrast agent may reduce renal function, but no such cases have been reported. MR peritoneography is also useful for diagnosing dialysate leakage, but the injection of gadolinium-based contrast agents in PD patients should be considered carefully, as there is a risk of nephrogenic systemic fibrosis [11]. MR imaging after the instillation of peritoneal dialysate without contrast agents has also proven useful for diagnosing RPL [5, 12].

Although the exact cause remains unclear in this case, potential contributing factors include the following: (1) a history of right inguinal and umbilical hernias, suggesting congenital weakness of the abdominal wall, and (2) the presence of the Chilaiditi sign, indicating a congenital positional anomaly of the colon, such as elongation, laxity, or absence of suspensory ligaments [13]. In this case, abdominal CT before the initiation of CAPD revealed interposition of the small intestine, large bowel, and gastric pylorus to the duodenal bulb between the liver and diaphragm (Fig. 6). It is speculated that dialysate retention increases intra-abdominal pressure and volume, and when the gas-filled colon rises under the diaphragm, the retroperitoneum is compressed, causing retroperitoneal injury.

Fig. 6

Abdominal plain computed tomography image before the initiation of CAPD. There is interposition of the small intestine (white arrow), large bowel (black arrow), and gastric pylorus to the duodenal bulb (arrowheads) between the liver and diaphragm

The optimal surgical treatment for RPL remains unclear because of the inaccuracy of CTP and MR peritoneograpy in identifying the leakage site. However, if the leakage site is identified during laparoscopic surgery, the treatment duration may be shortened by suturing and/or reinforcement with polyglycolic acid sheets or tissue adhesives (fibrin glue).

In conclusion, RPL is a rare complication of PD and is commonly diagnosed on the basis of dialysate leakage. While CTP is useful for diagnosis, plain abdominal CT maybe sufficient if there is suspicion of the possibility of RPL. The aim of this report is to emphasize the importance of considering RPL as a cause of UFF.