Details of flexible stylet method

Alpha-replacer

The alpha-replacer, which is developed in the late 1990s (JMS Co., Ltd., Tokyo, Japan, English homepage; http://www.jms.cc/english/index.html), is described in our previous report [4]. Briefly, the unique feature of the alpha-replacer is that this metal wire is usually soft, but becomes harder if coiled in the hand (Additional file 1). Such unique characteristic of alpha-replacer, or difference to ordinary guide-wire, is owing to its structure: The alpha-replacer comprises an inside “rope” and peripheral “spring” structure (Fig. 1). Precise detail regarding structure and characteristics of alpha-replacer is described elsewhere [4]. In Japan, alpha-replacer is widely used as a special wire-type equipment for transluminal replacement of a displaced peritoneal catheter.

Additional file 1: The general feature of alpha-replacer.

Insertion procedure

First, (a) a soft alpha-replacer covered with a PDC is inserted into the abdomen (Fig. 2). Next, (b) the wire is further inserted toward the Douglas pouch under fluoroscopic guidance. Then, (c) the alpha-replacer is slightly coiled in the hand, and the PDC is inserted following the slightly hardened wire. Procedures (b) and (c) are repeated alternately until the PDC tip is placed into the rectouterine pouch (Fig. 3). The representative maneuver (using simulator instead of real patient) is shown in Additional file 2, and real surgical field (of case 1) is shown in Additional file 3.

Additional file 2: The representative maneuver of flexible stylet method.

Additional file 3: The maneuver of flexible stylet method in real surgical field.

Consequence

The maneuver was completed successfully in all patients within 5 min except for case 7 (15 min) whose bowel adhesion was severe. Neither of the patients complained of pain during the procedure. After operation, the PDC tip was confirmed to be in the correct position in the Douglas pouch using abdominal X-ray in all cases (Fig. 4).

In all cases, exchange of peritoneal dialysate was started the next day of PDC insertion. Temporal bloody effluent was observed for a few days in case 2. Besides, no complications were developed in all cases. After PDC insertion, the exchange of peritoneal dialysate was undergone without any trouble in all cases: neither dialysate leakage nor peritonitis was observed. All patients were discharged from the hospital after they mastered manipulation regarding peritoneal fluid exchange (6 to 37 days after PDC insertion).

Discussion

In this report, we adapted the new technique named “flexible stylet method” for the insertion of PDC to ESRD patients with high risks (organic adhesion, bleeding tendency, poor cardiac function, or malnutrition, or some of these). As a result, we completed successful maneuver without any severe complication.

The flexible stylet method described herein is considered superior to that using a hard stylet with regard to at least three points. The first point is safety. As alpha-replacer is very soft when the equipment itself is inserted toward the minor pelvic space (for alpha-replacer is not hardened at this timing), the risk of organ injury can be minimized. In fact, bowel injury due to alpha-replacer usage has not been reported until now [4, 5]. The second point is effectiveness. Although a fluoroscopically guided PDC insertion procedure using a fine guide-wire has already been reported [6, 7], the use of alpha-replacer that can be hardened when needed offers us more accurate placement of the PDC tip into the minor pelvic space. The third point is the simplicity of the procedure, as described herein.

The alpha-replacer is a unique equipment developed specifically for transluminal replacement of a displaced PDC, and has a double-spiral structure that confers unique characteristics to the equipment [4]. By coiling this in the hand, the free tip becomes hard, and release allows the free tip to become soft (Additional file 1). Proper adaptation of such characteristics in procedures should improve both the safety and success rate of PDC implantation.

The flexible stylet method is considered safe, effective, and simple. However, some limitations regarding this method remain. The first limitation is radiation exposure for fluoroscopic guidance. The second limitation is the somewhat complexity for the staffs of theater. The third limitation involves indications. We applied the present method to limited high-risk cases only. However, from the viewpoint of safety management, the flexible stylet method might be applied also to moderate or normal risk cases. The fourth and most important limitation is that the number of treated patient is relatively small (eight patients). The incidence of perforations reported in previous report is about 0.7 to 2.6 % (one complication versus 40 to 140 PDC insertion) [8]. Thus, larger number of patient might be required to prove “real” incidence of perforations regarding this flexible method.

As the mean age of ESRD patients initiated dialysis therapy is increasing year by year [9], potential risk concerning PDC insertion is thought to be also increasing. We believe that flexible stylet method contributes to wide utilization of peritoneal dialysis therapy in the era of an aging ESRD population.