A single-center experience on percutaneously performed partial omentectomy in pediatric peritoneal dialysis patients

Abstract

Objective: This study describes a single-center experience on percutaneously performed partial omentectomy procedure in pediatric peritoneal dialysis (PD) patients who showed early catheter dysfunction and required catheter replacement due to catheter flow obstruction. Materials and methods: We performed a retrospective review of clinical outcomes from pediatric PD patients who underwent percutaneous catheter replacement by pediatric nephrologists between November 1995 and December 2012. Partial omentectomy was performed in those patients in whom omental or adhesion trapping to the catheter tip was seen. Results: During the study period, catheter dysfunction that eventually required percutaneous catheter replacement occurred in 32 (23.7%) children. Of these, 9 patients were performed partial omentectomy. Mean age at initiation of PD and time of omentectomy was 97.48 ± 46.06 and 98.53 ± 45.55 months, respectively. Catheter dysfunction appeared after a mean 1.20 ± 1.0 months. The causes of catheter dysfunction were omental wrapping and malposition. No peritonitis occurred before omentectomy. Mean total operation time was 60 ± 8.83 min. No complications were encountered during the procedure. After omentectomy, mean catheter survival period was 5.92 ± 6.88 months. A total of five peritonitis episodes occurred. Three patients were transferred to hemodialysis. Six patients were on PD treatment without any problem at the end of the first year of their follow-up. Two patients underwent kidney transplantation. Four patients were still on chronic PD treatment at the end of the study period. Conclusion: When performed by an experienced nephrologist, the performance of partial omentectomy by percutaneous route, when required, is an easy, safe and efficient therapeutic procedure in children on chronic PD treatment.

• Catheter replacement
• children
• chronic peritoneal dialysis
• partial omentectomy
• percutaneous

Introduction

Peritoneal dialysis (PD) is the most preferred renal replacement treatment in children with end-stage renal disease (ESRD).1–3 However, it is well known that the maintenance of PD treatment depends on a well-functioning PD catheter.4 A significant number of catheter complications and failures in PD are attributable to catheter malfunction, especially in the early periods of PD treatment, requiring the need for catheter revision or replacement.2–11

Omental wrapping, malposition of the tip of the catheter caused by omental adhesions and fibrin plugging blocking the side holes of the catheter are the leading causes of PD catheter malfunction in the early period of PD treatment that necessitate correction. Following the placement of a PD catheter into the peritoneal cavity, due to the ability of the omentum to adhere to intra-abdominal foreign bodies, the catheter can be surrounded and occluded by omentum. This may lead to drainage problems in PD patients requiring long-term catheters placed intra-abdominally. In such patients, omentectomy may lead to a reduction in the incidence of catheter blockage and confers improved utility of PD catheters.3,9,11

Although laparoscopic or open surgical omentectomy techniques are widely performed methods to improve catheter survival,3,8–11 in our opinion, to ensure the sustainability of PD treatment, pediatric nephrologists should be able to manage all catheter-related complications, including percutaneous partial omentectomy during catheter replacement or revision by percutaneous route to prevent catheter blockage.

In this study, we wanted to share our experience about percutaneously performed partial omentectomy procedure at the time of catheter replacement in pediatric PD patients who showed catheter dysfunction and required catheter replacement due to catheter flow obstruction.

Materials and methods

The study was conducted on children with ESRD, who were on PD from December 1995 to December 2012, at the Department of Pediatric Nephrology, Izmir Tepecik Training and Research Hospital, Turkey. Children were excluded from the study if the PD catheter was used for acute renal failure. We retrospectively reviewed the clinical outcomes of pediatric PD patients who underwent catheter replacement procedure by percutaneous route during this period. Before the PD catheter replacement procedure, the children and their families were explained about the rationale of PD catheter replacement and written informed consent was obtained before this process. Percutaneous partial omentectomy was performed only in those patients in whom omental or adhesion trapping to the catheter tip was seen at the time of catheter replacement procedure.

All PD catheter replacement procedures were performed percutaneously by an experienced pediatric nephrologist. We used swan-neck (Tenckhoff), double-cuffed catheters with coiled tips. Pre-operative laboratory results included complete blood count, basic metabolic panel, prothrombin time, partial thromboplastin time, typing and screening for two units of blood. A bowel enema (Libalaks®, Liba Laboratories, Turkey, rectally) was performed to all children 45 min before catheter replacement to prevent bowel perforation. A Foley catheter was also placed to drain off the urinary bladder.

Catheter replacement and partial omentectomy

The percutaneous PD catheter replacement procedure was performed under local anesthesia in the procedure room. All procedures were carried out under strict aseptic conditions (for doctors: cap, mask, sterile gown and double sterile gloves; for nurses: cap, mask and sterile glove; for patient: mask and cap). After the children were laid in supine position, the skin was prepared with antiseptic solution (baticon) five times. Under local anesthesia, a vertical incision was made at the level of patient’s previous incision scar. Blunt dissection was carried down to the subcutaneous tissue until the catheter and rectus sheath was seen. Local anesthetic was infiltrated around the superficial and deep cuffs. Blunt dissection was continued toward the superficial cuff. Subcutaneous blunt dissection was performed throughout the tunnel in the longitudinal direction to the superficial cuff. After the adhesions around the superficial cuff were separated using blunt or sharp dissection, the catheter was removed from the incision site. After that, blunt dissection was continued toward the deep cuff. Once the deep cuff was separated from the surrounding tissue using forceps, the intraperitoneal part of the catheter was slowly withdrawn and cautiously controlled. If omental wrapping or adhesion was seen at the tip of the catheter, partial omentectomy procedure was intended. The omentum portion that protrudes from the port site was firmly ligated from the bottom by absorbable catgut. The part of the omentum above the ligature was then cut away by scalpel or scissors (Figure 1). To verify that the material removed was an omentum part, samples were sent to pathology clinic for histologic examination. After bleeding control, the same or a new PD catheter, which was washed with heparinized solution, was threaded on a stiffening stylet and introduced towards the left iliac fossa until the patient experienced a pain at the perianal region. According to the pain experienced, the tip of the catheter was placed in the Douglas pouch. Approximately 50–100 mL heparinized saline is infused rapidly; its outflow is assessed to confirm adequate function.

Figure 1. The performance of percutaneous partial omentectomy. Omental wrapping or adhesion at the tip of the catheter (A). The seperation of omentum portion that protrude from the port site from the catheter (B). After removal of the catheter, the ligation of and cut away the omentum part from the bottom (C). The sample of the omentum part removed (D).

After inserting the catheter, the inner cuff of the PD catheter was fixed at the fascia of the rectus muscle. Using previously performed subcutaneous tunnel, the end of the catheter was attached to a specially designed hook-shaped stylet and the tip of the hook was pushed through the subcutaneous tissue in a right laterocaudal direction. The proximal end of the catheter was pulled through the exit-site and positioned so that the inner cuff was located at the peritoneal entry at the fascia of the rectus muscle and the second cuff was >2 cm from the exit-site. The titanium adaptor was then added to the proximal end of the catheter. The operation was completed by closing the incision with two or three sutures. The skin was cleaned with antiseptic solution five times again. The mupirocin ointment was applied to the catheter exit-site and tip of the tunnel followed by covering with a transparent, oxygen-permeable dressing. The total procedure time was calculated as time from the entrance to the procedure room to the time the dressing was covered. Except for patients who required urgent initiation of PD, children were started on PD treatment 2 weeks after partial omentectomy.

We studied the demographical data, patient characteristics, surgical records, early catheter complications requiring catheter replacement, post-omentectomy complications, outcomes, the need for another renal replacement therapy, post-omentectomy peritonitis frequency and operation time.

Statistical analysis was made by using IBM SPSS 20.0 software (SPSS, Chicago, IL).

Results

Between November 1995 and December 2012, 135 children with ESRD was performed percutaneous PD catheter placement by an experienced pediatric nephrologist in our Pediatric Nephrology unit. Of these, 32 (23.7%) patients required a replacement procedure due to persistent peritonitis (in 1 patient), malfunction (in 24 patients), leakage (in 3 patients) and intractable abdominal pain (in 4 patients). During the replacement procedure, just after the catheter was removed, 9 out of 32 (28.12%) patients in whom we observed an omental protrusion from the port site due to omental or adhesion trapping to the catheter tip underwent percutaneous partial omentectomy. Among these 9 patients, 5 (55.6%) were boys and 4 (44.4%) were girls. The mean age at initiation of PD and at the time of percutaneous partial omentectomy was 97.48 ± 46.06 months (range: 25.25–143.43 months) and 98.53 ± 45.55 months (range: 26–146.07 months), respectively. Patient characteristics, underlying etiologies and outcomes are given in Table 1.

Table 1. Patient characteristics, underlying etiologies and outcomes of the study group.

Parameter	n (%)
Gender
Male	5 (55.6)
Female	4 (44.4)
Etiology
VUR	1 (11.1)
Urologic abnormalities without VUR	4 (44.4)
Chronic glomerulonephritis	2 (22.2)
Other	2 (22.2)
Previous abdominal surgery
Yes	3 (3.33)
No	6 (66.7)
Reasons for catheter replacement
Flow obstruction	5 (55.6)
Malposition	4 (44.4)
Age at PD start (months)	97.48 ± 46.06
Age at partial omentectomy (months)	98.53 ± 45.55
Number of peritonitis episodes (n)
Pre-omentectomy	0
Post-omentectomy	5
Operation time (min)	60 ± 8.83
Complication
Yes	0 (0)
No	9 (100)
One-year outcomes
PD	6 (66.7)
HD	3 (33.3)
Tx	0 (0)

Notes: VUR, vesicoureteral reflux; PD, peritoneal dialysis; HD, hemodialysis; Tx, transplantation.

The mean time to the need for catheter replacement in these 9 patients was 1.20 ± 1.0 months (range: 0.1–2.9 months). The reasons were omental wrapping (in 5, 55.6%) and malposition (in 4, 44.4%). The mean total operation time was calculated as 60 ± 8.83 min (range: 48–74 min). No complication occurred during or after partial omentectomy procedure. Only one patient required urgent PD treatment after partial omentectomy procedure. These nine patients experienced no peritonitis episode before catheter replacement whereas a total five peritonitis episodes (four in one patient, one in one patient) after omentectomy. The mean peritonitis free-time after omentectomy was calculated as 5.92 ± 6.88 months (range: 0.03–19.26 months). The rate of having a functioning catheter after 1 year and median catheter survival time after omentectomy was 55.6% (in 5 patients) and 3.3 months (range: 0.03–19.26 months), respectively. Four out of nine patients developed drainage problems and required a second replacement. The reasons for second replacement were malposition of the catheters. No omental protrusion was seen in these patients. Of these, three (33.3%) patients showed persistent catheter flow obstruction requiring catheter removal and were transferred to hemodialysis treatment. Six patients were on PD treatment without any catheter-related drainage problem at the end of the first year of their follow-up. Two patients (22.2%) underwent successful kidney transplantation. Four patients (44.4%) were still on chronic PD treatment at the end of the study period.

Discussion

In this study, we present for the first time an alternative method for partial omentectomy performed by our pediatric nephrology team via percutaneous route during the percutaneous catheter reimplantation procedure in those pediatric PD patients who exhibit an omental protrusion from the abdominal wall due to omental or adhesion trapping to the catheter tip. Specifically, during the study period, only nine pediatric patients had percutaneous partial omentectomy done at the time of their catheter replacement procedure by percutaneous route. In this article, we showed that the performance of percutaneous partial omentectomy, whenever required, attempted by experienced pediatric nephrologists is an easy, safe and efficient therapeutic procedure with few complications in children on chronic PD.

Catheter failure has been reported to occur in as many as 21–42% of children undergoing peritoneal catheter placement.3,6,8,12,13 In these studies, surgical placement was the main technique.3,8–11 On contrary, ours is a study of percutaneously-placed PD catheters. The rate of catheter dysfunction that eventually required catheter replacement was 23.7% (32 out of 135 patients) in the present study. Of these, nine patients were performed percutaneous partial omentectomy by us. We previously reported a study of percutaneously placed PD catheters in children on chronic PD, emphasizing that a pediatric nephrologist should be able to apply the interventional procedures related with ESRD in children.14 Although experience is of paramount importance, present study demonstrates that a pediatric nephrologist who can place a PD catheter can also remove a PD catheter as well as can perform, when required, partial omentectomy without a major complication. In our opinion, our results are comparable with the limits of a desirable pediatric PD center.

A partial omentectomy involves the removal of only a proportion of the omentum. Laparoscopic and open surgical omentectomy techniques are widely used methods.11,13,15,16 To our knowledge, this is the first report to describe percutaneously performed partial omentectomy in pediatric PD patients. In our opinion, percutaneous omentectomy, when a catheter enveloped by omentum is identified at the time of catheter replacement, is a minimally invasive means of salvaging non-functioning PD catheters. Partial omentectomy during percutaneous catheter replacement or revision can prevent catheter blockage and secondary interventions. Also, complications are few and this technique can allow rapid return to PD.

The mean total operation time of percutaneous partial omentectomy (including replacement) in the current study was lower to the results in other studies of surgical salvage.9,17 A low operation time in our percutaneous group was probably due to the performance of this technique under local anesthesia. However, the retrospective nature as well as the small sample size of our study makes comparison with other studies difficult.

To date, few complications with the performance of surgical omentectomy, in very few cases, have been reported in the medical literature. Reported complications regarding the omentectomy procedure are hemorrhage at the site of surgery, hemoperitoneum and hernia at trochar site.8–10 On the other hand, some studies reported no complications after omentectomy.3,15,16 In our study, no complication was observed during and after percutaneous partial omentectomy. Although the small sample size of this study does not allow a true assessment for catheter survival, 1-year catheter survival in our study was 55.6% following partial omentectomy, less than those reported studies in the literature.16–18

To our knowledge, to date, no information exists about the incidence of omental wrapping or adhesion to the catheter tip at the time of catheter replacement or revision procedure by percutaneous route. The lack of this information might be due to the anxiety of the nephrologists of not knowing exactly how to overcome this annoying medical problem. In our series, omental wrapping during the percutaneous replacement procedure was seen in 28.1% of the patients with non-functioning catheters.

In conclusion, our data suggest that percutaneous partial omentectomy can be performed, uneventfully, by pediatric nephrologists. Therefore, we believe that percutaneous omentectomy practice should be a part of the pediatric nephrologist training and pediatric nephrologists, whenever indicated, should be eager for performance partial omentectomy during PD catheter replacement.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.