Chapter 58. Interventional Nephrology: Peritoneal Dialysis Catheter Procedures

In addition to being a continuous daily home therapy, peritoneal dialysis (PD) offers a number of advantages for end-stage renal disease (ESRD) patients. Nevertheless, PD remains an underutilized form of renal replacement therapy. Recent data demonstrate that over 50% of ESRD patients in the United States prefer and request PD as the modality of choice for renal replacement therapy. However, only 12% of ESRD patients are initiated on this form of therapy. A variety of factors including timely insertion of PD access are likely responsible for the dramatic underutilization of PD. Recent attention has focused on increasing the use of this important modality of renal replacement therapy. To this end, interventional nephrologists have taken the initiative in performing PD access-related procedures, including catheter insertion, catheter removal, and repositioning of a migrated catheter. The safety and success of PD access-related procedures by nephrologists have been well documented.

This chapter provides a review of PD catheter types, catheter placement procedures, and management of some catheter-related complications. It emphasizes the importance, feasibility, and advantages of PD access procedures by nephrologists.

Types

Chronic PD catheters are designed to be used for many months or years. They are constructed of soft materials ssuch as silicone rubber or polyurethane. The intraperitoneal portion usually contains 1-mm side holes, although one version has linear grooves or slots rather than side holes. All chronic PD catheters have one or two extraperitoneal Dacron cuffs that promote a local inflammatory response. This produces a fibrous plug that fixes the catheter in position, preventing fluid leaks and bacterial migration around the catheter. Chronic PD catheters are the most successful of all transcutaneous access devices, with longevity measured in years rather than days to months. Peritoneal access failure, however, is still a source of frustration for all continuous ambulatory peritoneal dialysis (CAPD) programs, and it is the reason why about 25% of patients drop out. Increasing the success of a CAPD program requires optimal use of peritoneal catheters. Currently, the method of catheter placement has more effect on outcome than catheter choice.

As shown in Figure 58–1, at first there appears to be a bewildering variety of chronic PDs. However, each portion of the catheter has only a few basic design options.

There are four designs of the intraperitoneal portion:

1. Straight Tenckhoff, with an 8-cm portion containing 1-mm side holes.

2. Curled Tenckhoff, with a coiled 16-cm portion containing 1-mm side holes.

3. Straight Tenckhoff, with perpendicular discs (Toronto-Western, rarely used).

4. T-fluted catheter (Ash Advantage) a T-shaped catheter with grooved limbs positioned against the parietal peritoneum.

There are three basic shapes of the subcutaneous portion between the muscle wall and the skin exit site:

1. Straight or gently curved.

2. A 150° bend or arc (Swan Neck).

3. A 90° bend, with another 90° bend at the peritoneal surface (Cruz “Pail Handle” catheter).

There are three positions and designs for Dacron cuffs:

1. A single cuff around the catheter, usually placed in the rectus muscle but sometimes on the outer surface of the rectus.

2. Dual cuffs around the catheter, one in the rectus muscle and the other in the subcutaneous tissue.

3. A disc-ball deep cuff with the parietal peritoneum sewn between the Dacron disc and silicone ball (Toronto–Western and Missouri catheters).

There are three internal diameters, each having an outer diameter of approximately 5 mm (Figure 58–2).

1. 2.6 mm, the standard Tenckhoff catheter size.

2. 3.1 mm, the Cruz catheter.

3. 3.5 mm, the Flexneck catheter.

There are two materials of construction:

1. Silicone rubber (nearly all catheters).

2. Polyurethane (Cruz catheter).

The various intraperitoneal designs are all created to diminish outflow obstruction. The shape of the curled Tenckhoff catheter and the discs of the Toronto-Western catheter hold visceral peritoneal surfaces away from the side holes of the catheter. The grooves of the Advantage catheter distribute flow over the surface of the limbs that contact the parietal peritoneum, providing a much larger surface area for drainage than the side holes provide. An irritated omentum attaches firmly to the side holes of a catheter but only weakly to the grooves on a catheter (as demonstrated by the Blake surgical drain, with grooves on the catheter surface).

The subcutaneous catheter shapes all provide a lateral or downward direction of the exit site, which minimizes the risk of exit infection. An upward-directed exit site collects debris and fluid, increasing the risk of exit-site infection.

The optimal location for the standard deep cuff is within the rectus muscle. The subcutaneous cuff provides additional protection from bacterial contamination of the subcutaneous tunnel. The disc-ball deep cuff provides security of position of the catheter, since with the peritoneum sewn between the Dacron disc and intraperitoneal ball the catheter is fixed in position and cannot migrate outward. Similarly, the T shape of the Advantage catheter places the intraperitoneal limbs against the parietal peritoneum, preventing outward migration of the catheter.

The larger internal diameter of the Cruz and Flexneck catheters provides lower hydraulic resistance and more rapid dialysate flow during the early phase of outflow. In the latter part of outflow, the resistance to flow is determined mostly by the spaces formed by peritoneal surfaces as they approach the catheter, rather than the inside of the catheter. The Advantage catheter provides much larger entry ports for drainage of peritoneal fluid; limited clinical studies have demonstrated faster drainage of the peritoneum in the early and late phases of outflow and a decrease in residual peritoneal volume at the end of outflow.

The material from which peritoneal catheters are constructed has not affected the incidence of complications. There is no decrease in the incidence of peritonitis or omental attachment leading to outflow failure with polyurethane catheters, although they do have a weaker bond to the Dacron cuff, and loosening of this bond can create pericatheter leaks.

Proper Location of Components

There is general agreement on the proper location of the components of chronic PD catheters (Figure 58–3):

1. The intraperitoneal portion should be between the parietal and visceral peritoneum and directed toward the pelvis to the right or left of the bladder.

2. The deep cuff should be within the medial or lateral border of the rectus sheath.

3. The subcutaneous cuff should be approximately 2 cm from the skin exit site.

Placing the deep cuff within the abdominal musculature promotes tissue ingrowth and therefore avoids pericatheter hernias, leaks, catheter extrusion, and exit-site erosion. At the parietal peritoneal surface, the squamous epithelium reflects along the surface of the catheter to reach the deep cuff. If the deep cuff is outside the muscle wall, the peritoneal extension creates a potential hernia. At the skin surface, the stratified squamous epithelium follows the surface of the catheter until it reaches the superficial cuff. If the exit site is longer than 2 cm, the squamous epithelium disappears and granulation tissue is left, leading to an exit site with continued “weeping” of serous fluid; the potential for exit site infection is therefore increased.

Some peritoneal catheters have components that provide greater fixation of the deep cuff within the musculature. When the Missouri and Toronto-Western catheters are placed, the parietal peritoneum is closed between the ball (inside the peritoneum) and disc (outside the peritoneum). When the T-fluted (Ash Advantage) catheter is placed, the wings open in position adjacent to the parietal peritoneum and perpendicular to the penetrating tube. With these catheters, outward migration of the catheter is impossible.

When placing peritoneal catheters it is best to choose a deep cuff location that is free of major blood vessels (Figure 58–4).

Methods of Implantation

PD catheter insertion can be accomplished by any one of three techniques: the dissective or surgical, the blind or modified Seldinger, and the peritoneoscopic. The dissective technique utilized by most surgeons places the catheter by minilaparotomy, usually under general anesthesia. In the blind or modified Seldinger technique a needle is inserted into the abdomen, a guide wire is placed, a tract is dilated, and the catheter is inserted through a split sheath, all without visualization of the peritoneal cavity. Peritoneoscopic insertion uses a small (2.2-mm-diameter) optical peritoneoscope (Y-TEC Scope) for direct inspection of the peritoneal cavity and identification of a suitable site for the intraperitoneal portion of the catheter.

There are advantages and disadvantages of each technique of catheter placement, and the overall success of the catheters is as dependent upon the skill and experience of the physician performing the procedure as the method of placement. Each procedure has unique advantages and problems.

Dissective techniques securely place the deep cuff within the abdominal musculature. The techniques can be performed without any specialized equipment except for a stylet to straighten the catheter. Some types of catheters require surgical placement, such as the disc-and-ball Missouri or Toronto-Western catheters. The incision in the abdominal musculature requires surrounding tissues to first heal the wound and then grow into the deep cuff before the deep cuff is secure. Pericatheter leaks are frequent if the catheter is used immediately after placement. The dissective approach provides no visualization of adhesions and free spaces within the peritoneum. The catheter tip is advanced by “feel” and may be advanced to press against loops of bowel, or near adhesions, leading to early outflow failure of the catheter.

Blind placement procedures are convenient, can be performed anywhere in a hospital, and have the advantage of being low in cost. The needle, guidewire, dilators, and sheath are often packed in a kit with the peritoneal catheter. Bowel perforation is an occasional complication, usually not recognized until the catheter has been completely placed and is flushed. No visualization of the peritoneal space is provided to avoid impingement of the catheter tip on adhesions or visceral surfaces. The deep cuff is usually left just outside of the abdominal musculature, not within the rectus sheath.

Peritoneoscopic placement allows the best visualization of the peritoneal space. This avoids placing the catheter under bowel loops, under omentum, or against adhesions. The Quill expands to allow the deep cuff to advance into the musculature. The Y-TEC procedure can be performed in any room in the hospital. Specialized equipment must be purchased, however, and the physician must have some training in peritoneoscopic techniques. Of the three techniques, only the latter allows for direct visualization of the intraperitoneal structures. The use of this technique, most commonly employed by nephrologists, is rapidly expanding. Peritoneoscopic placement varies from laparoscopic techniques by using a much smaller scope and puncture size, only one peritoneal puncture site, a device to advance the cuff into the musculature, air in the peritoneum rather than CO2, and local rather than general anesthesia.

The preference of one technique over another must take into account the incidence of complications (pericatheter leakage, exit site and tunnel infection), the long-term catheter survival associated with each technique, the costs, ease, and timely insertion of the catheter, and factors contributing to risk of mortality (general anesthesia). To this end, peritoneoscopic placement of PD catheters by nephrologists has been rigorously compared to the surgical and the blind technique (Table 58–1). Both randomized and nonrandomized studies have documented the superiority of the peritoneoscopic technique in terms of a lower incidence of catheter complications (infection, outflow failure, pericatheter leak) and increased catheter survival. The avoidance of various complications by peritoneoscopic placement may relate to the decreased tissue dissection required with this technique. Extensive dissection (incising/splitting the rectus sheath/muscle as well as incising the parietal peritoneum) in the surgical technique may lead to loose attachment of the catheter to the abdominal wall, thereby increasing the incidence of pericatheter leaks, subsequent tunnel infection and peritonitis, and catheter loss.

Peritoneoscopic insertion of a PD catheter by a nephrologist can be safely performed in a procedure room, an interventional laboratory, or an intensive care unit using standard precautions for infection control. Conversely, the dissective surgical technique requires a surgeon, operating room facilities and staff, and anesthesia services. In addition, a second admission and surgical procedure for catheter exteriorization may be required for catheters that are buried on placement. The surgical approach introduces delays and restrictions inherent in the system and increases costs. At our center, the average time between the initial contact with the interventional nephrology team and PD catheter insertion was markedly shortened to 6.4 ± 0.9 days (mean ± SE), in contrast to the prior 34.3 ± 1.6 day (mean ± SE) delay when catheters were placed by the surgeon. Since tissue dissection is minimal with the peritoneoscopic technique, the postoperative course is brief and the catheter can be used immediately for some schedule of PD (such as with overnight exchanges with the patient at rest, dry during the day). A 2- to 3-week postoperative period for complete wound healing is recommended before implementing CAPD.

Mortality risk from general anesthesia varies with the American Society of Anesthesia (ASA) physical status categories. These range from class I to V. Class I includes patients with no physiologic or psychologic stress (minimal risk) and class V describes patients with severe systemic disturbances. For class II patients (mild-to-moderate systemic disturbances, such as essential hypertension, diabetes, or anemia) mortality is estimated at 3/1000. The mortality rate increases with moderate-to-severe disturbances reaching 1.8% for class III and 7.8% for class IV patients. ESRD patients usually have multiple complex and advanced medical problems. Therefore, avoiding general anesthesia and its inherent risk is a major advantage. Utilizing local anesthesia for PD catheter placement avoids the risks of general anesthesia. Among methods of placement, the peritoneoscopic method (performed by nephrologists, generally) has the lowest incidence of infectious complications over the life of the catheters. This may relate to the decreased amount of tissue trauma and smaller incision size of the peritoneoscopic placement versus dissective placement and better assurance that the cuff is placed within the muscle versus blind placement. Outflow failure and leaks are comparable between peritoneoscopic placement and surgical dissection, but are higher with blind placement. This relates to the lack of peritoneal visualization during positioning of the catheter with blind techniques and to the positioning of the cuff outside the rectus sheath rather than within the rectus muscle (in general).

There are also differences in the use of catheters according to the method of placement. Peritoneoscopically placed catheters may be used for PD treatments immediately to support the patient without the need for hemodialysis in almost any schedule that does not include full volume of the peritoneum during times of activity. This includes night-time cycler therapy or overnight exchanges, but excludes full-volume CAPD. Some surgically placed catheters may also be used immediately, but this involves modifying the technique. One approach is to angle the catheter course through the rectus muscle, separating the site of penetration of the anterior and posterior rectus sheaths and maintaining the cuff position in the middle of the rectus muscle.

In summary, with optimal training in PD catheter insertion, a nephrologist can perform PD catheter placement safely and successfully. The American Society of Diagnostic and Interventional Nephrology (ASDIN) has established accreditation guidelines for training centers and certification guidelines for individual physicians to obtain the necessary skills in PD catheter placement. Although two nephrologists would be ideal, a PD access placement program can be successfully initiated by a single trained nephrologist. When peritoneal catheter insertion is performed by nephrologists, a variety of advantages can occur for the patient, some related to the procedure of peritoneoscopy and some related to the timeliness and continuity of care (Table 58–2). However, the success of the procedure is tantamount to patient benefit. The placement of PD catheters should be performed by the physician with the best outcomes, using whatever technique is most successful in their hands.

Effects of Design on Catheter Success

Randomized, prospectively controlled studies have generally shown little effect of catheter design on the success of peritoneal catheters, although one study demonstrated a longer 3-year survival of coiled versus straight Tenckhoff catheters. If properly placed, dual-cuff Tenckhoff catheters have a lower incidence of exit-site infection and longer lifespan than single-cuff catheters, although properly placed single-cuff catheters can work as well. Curled Tenckhoff catheters have a lower incidence of outflow failure than straight catheters. Swan neck catheters have a lower incidence of exit-site infection than those with straight subcutaneous segments. Nonrandomized studies of specific catheters have indicated various advantages, including the fact that catheters with the best fixation of the deep cuff (such as the Missouri and Advantage catheters) have a very low incidence of exit-site infection.

Some silicone Tenckhoff catheters, such as the Flexneck, have a larger internal diameter and thinner walls (Figure 58–2). These catheters are more pliable and create less tension between deep and superficial cuffs during normal patient activities. This may result in a lower incidence of pericatheter leaks and hernias and fewer exit-site and tunnel erosions, although any real advantages are as yet unproven. A problem with Flexneck catheters is that they are prone to crimping in the subcutaneous tunnel if they are angled sharply. If physicians follow a template to create the subcutaneous tunnel with a gentle downward curve, crimps in the subcutaneous tract are eliminated. Flexneck catheters, such as the Cruz catheter, have a higher rate of inflow and initial outflow than catheters with standard, smaller internal diameters. Rapidity of flow at the end of outflow for the Cruz catheter is partly due to the 90° angle of the catheter at the parietal surface, which positions the coiled portion next to the parietal peritoneal surface. Catheters constructed from polyurethane (such as the Cruz) have excellent strength and biocompatibility. The glue bonding of the Dacron cuffs to the catheters, however, often fails within 1–2 years of use, resulting in pericatheter leaks and sometimes infections.

The Advantage catheter contains a straight portion that is adjacent to the parietal peritoneum, ensuring a stable position without extrusion of the deep cuff or exit site erosion (similar to the disc-ball catheters and the older Lifecath catheter). Advantage catheters placed in patients beginning PD and those with previous Tenckhoff failures demonstrate a 1-year survival of 90%, higher than the 50–80% survival of Tenckhoff catheters in numerous studies (Figure 58–5). During follow-up of 42 patients with Advantage catheters in place for up to 4 years, only one patient developed a pericatheter leak (resolved by delaying CAPD), and no patient developed a pericatheter hernia or late exit infection. The outflow rate of PD fluid is on average equal to the best functioning Tenckhoff catheters (including the large internal diameter Flexneck catheters). The total outflow volume is more consistent with the Advantage catheter. In CAPD exchanges with the same glucose concentration and dwell time the Advantage catheter has a standard deviation of 2% versus 10% for Tenckhoff catheters. The more consistent peritoneal outflow is probably due to more complete drainage of the peritoneum, with a diminished residual volume, but this has also not been proven. Diminished residual volume is important, since if residual volume is decreased by 300–500 mL, the inflow volume can be increased by the same amount, thus increasing the peritoneal clearance by 10–20% without increasing patient discomfort by overfilling the abdomen.

Advantage peritoneal catheters may diminish the risk of outflow failure, but do not eliminate this risk. The mechanism of outflow failure is different from that in Tenckhoff catheters. The omentum does not directly attach to the intraperitoneal portion of the catheter, but rather surrounds the long, slotted catheter intraperitoneal limbs and traps them against the parietal peritoneum. Infusion of iodine dye during fluoroscopy demonstrates that the dye does not pass freely in many directions out of the grooves of the catheter, but rather stays near the catheter and exits from the ends of the intraperitoneal limbs. Laparoscopic removal of adhesions from around the catheter can often result in a perfectly functioning PD catheter. The negative features of the Advantage catheter include the fact that it is somewhat more complicated to insert, either during dissection or by peritoneoscopy. A special slotted “Key Tube” and guide are needed to hold the ends of the catheter together so that it can be inserted through the Quill guide or through a peritoneal opening. The catheter opens automatically when the tube and guide are retracted. Another problem with this catheter is that if the peritoneal fluid contains a considerable amount of blood or fibrin the small openings between the fluted limbs and the central T portion can block off. This usually resolves with some in/out flushes by a 20-mL syringe with saline, but sometimes tissue plasminogen activator infusion is necessary.

All PD catheters can serve as a nidus for infection, requiring removal in cases of persistent peritonitis. None of the new designs or materials has changed this. Peritoneal catheters with a long-term and effective antibacterial surface are still an elusive goal, but several new approaches to sterilization of biofilm are now being evaluated. Another challenge is to limit the growth of adventitial tissue around and onto catheters, such as in fibrous sheathing of central venous catheters and omental attachment to peritoneal catheters. Of course, these materials would have to be applied to the intravascular or intraperitoneal surfaces of the catheters and not in the subcutaneous space or on the cuffs.

New Placement Techniques

Several recent publications have described the use of laparoscopic techniques for the placement of peritoneal catheters. These techniques use the same 5- to 10-mm-diameter trocars generally used for laparoscopic surgery. These are much larger than the 2.2-mm peritoneoscope used in the Y-TEC system, and usually require general anesthesia and automated inflation equipment. The catheter is inserted through a large cannula into the abdomen, and it is difficult to ensure that the deep cuff is placed within the musculature until after the cannula is removed. In spite of the excellent visualization of the peritoneum with laparoscopic placement techniques, several studies have shown that catheters placed in this manner have a high frequency of pericatheter leak due to the large hole made in the musculature. As opposed to catheters placed with specially designed equipment, those placed by the laparoscopic technique have no advantage in terms of longevity over those placed by dissection. However, laparoscopy does provide knowledge of intraperitoneal anatomy that may be helpful in the placement of PD catheters in patients with previous surgeries and multiple adhesions. In fact, the visibility of the peritoneum is considerably greater than with the small peritoneoscope. Additionally, adhesion lysis is possible as is repositioning of the catheters using laparoscopy. In difficult cases laparoscopy, versus dissective placement, may be the preferable technique.

Burying the Peritoneal Dialysis Catheter

Traditional surgical implantation of Tenckhoff catheters involves immediate exteriorization of the external segment through the skin, so that the catheter can be used for supportive PD or for intermittent infusions during the “break-in” period. To prevent blockage and to confirm function, the catheter is flushed weekly with saline or dialysate; each exchange carries the same risk of peritonitis as in CAPD therapy. The catheter must also be bandaged and the skin exit site must be kept clean in the weeks after placement to avoid bacterial contamination of the exit site. The patient must therefore be trained in some techniques of catheter care. It has always been difficult to decide when to place a PD catheter in a patient with chronic renal insufficiency. If the catheter is placed too early, the patient may spend weeks to months caring for a catheter that is not used for dialysis. If the catheter is placed after the patient becomes uremic, it is often used for PD therapy without a “break-in” period.

A placement technique has been devised in which the entire peritoneal catheter can be buried under the skin some weeks to months before it needs to be used. The catheter burying technique was first described for placement of a modified Tenckhoff catheter with a 2.5-cm-long superficial cuff, but the technique has been adopted for standard dual-cuff Tenckhoff catheters. In the original technique the external portion of the catheter was brought through a 2- to 3-cm skin exit site (much larger than the usual 0.5 cm incision). The catheter was then tied off with silk suture and coiled and placed into a “pouch” created under the skin. The skin exit site was then closed. Weeks to months later, the original skin exit site was opened and the free end of the catheter was brought through the original skin large exit site.

The goal of burying the PD catheter was to allow ingrowth of tissue into the cuffs of the catheter without the chance of bacterial colonization and to allow a transcutaneous exit site to be created after the tissue had fully grown into the deep and subcutaneous cuffs. Burying the catheter effectively eliminated early pericatheter leaks and decreased the incidence of peritonitis. In 66 months of follow-up, patients with a buried Tenckhoff catheter had 0.017–0.37 infections per year versus 1.3–1.9 infections per year in control patients. In a study of 26 buried Tenckhoff catheters, the incidence of infection during PD was 0.8 infections per year and the incidence of catheter-related peritonitis was only 0.036 per patient-year. A retrospective study confirmed a significantly lower rate of catheter infection and peritonitis in patients who had buried catheters and a significantly longer catheter life, although the procedure was not effective when used for single-cuff catheters.

The incidence of exit-site infections is not generally decreased in patients with catheters that are buried and exteriorized, which may be explained by the increase in trauma near the exit site that occurs during burying and exteriorizing the catheter. A large exit site is created when the catheter is buried and a similarly large site is recreated when the catheter is exteriorized. Creating a “pouch” under the skin requires a considerable amount of dissection and trauma near the exit site. The size of the pocket limits the length of the catheter that can be coiled and buried under the skin, which limits the external length of the catheter after exteriorization. The exit site must be opened widely to remove the catheter, because the coil rests in a position distant from the skin exit site. Subcutaneous adhesions to the silk suture around the catheter further restrict removal. Increased trauma near the exit site during placement and exteriorization of the catheter may have caused an increased incidence of early exit infection with this technique. In a study of “embedded” catheters in 26 adult patients (with a mean subcutaneous residence of 79.5 days) two patients developed local seromas and 12 developed subcutaneous hematomas (five of which were revised surgically). There were a number of flow problems at catheter “activation”: Nine patients developed fibrin thrombi (two requiring operative clearance) and four patients had omental catheter obstruction (four requiring omentectomy). When burying the Tenckhoff catheter using standard techniques there were a total of 27 complications in 26 catheter placements, with 13 of these complications requiring corrective surgery.

When catheters are placed by the Y-TEC procedure the Quill and cannula of the system can be reassembled and used to bury the external portions of dual-cuff Tenckhoff and Advantage catheters. The catheter exit site is made slightly larger than the standard exit site. The Quill and cannula are inserted through this exit site to create a long, straight tunnel for the external end of the catheter. The catheter is blocked with an internal plug rather than an external silk suture. We have used this technique to bury and then remove over 40 Tenckhoff and Advantage catheters. There have been only a few early complications—insignificant hematoma (3%), seroma (0%), exit infection (3%), or outflow failure (0%)—and all catheters have functioned after exteriorization. Nephrologists can bury and exteriorize PD catheters with greater ease and less trauma than with surgical procedures and possibly obtain improved results.

In planning for hemodialysis of patients with ESRD, it is common practice to place fistulas or grafts several months before the need for initiation of dialysis, so that they can “mature” before use. PD catheters also “mature” after placement, with fibrous tissue ingrowth into the cuffs and the development of a fibrous tunnel. The fully ingrown catheter is more resistant to infection of the cuffs and the surface of the catheter. The technique of burying PD catheters after placement allows this maturation to occur before use of the catheter, much as with fistulas and grafts. It also allows the time of catheter insertion to be separated from the time of catheter use and avoids the patient having to learn how to care for the catheter site or observe the catheter site for potential complications. At the time of initiation of dialysis, the patient and physician can focus attention on the proper performance of the technique and patient response rather than on the function of the catheter. The patient can be trained in full-volume CAPD techniques rather than in “break-in” or cycler techniques used for immediately exteriorized catheters.

A curious aspect of the burying technique is that it seems contrary to “the rules” of catheter break-in. In immediately exteriorized catheters, it is necessary to infuse and drain the dialysate or saline (with or without heparin) at least weekly to prevent outflow failure or obstruction of the catheter. However, with the completely buried catheter, there is no infusion of any fluid for periods of up to 1 year. This may be possible because in the exteriorized catheter, stress and strain on the catheter and its compliance allow some fluid to enter and exit the side holes during patient movement. The buried catheter has less motion and with a secure blockage there is very little fluid inflow/outflow through the holes during normal activity. Furthermore, the infusion of saline or dialysate during break-in techniques adds a bioincompatible fluid to the abdomen at a time before the catheter is “biolized” or protein/lipid coated. The catheter becomes biolized in the absence of dialysate or saline in the peritoneum. When PD is begun, the catheter is already biolized and less likely to develop omental attachment, even in patients with an active omentum.

In general, a physician who places a device is responsible for following the success of the device and removing it when complications require removal or when it is no longer needed. Removal of a PD catheter can be safely performed by nephrologists without significant discomfort under local anesthesia, although Toronto=Western catheters require more dissection and the patient may require conscious sedation. The procedure should be done only with a sterile technique, good lighting, antiseptic skin preparation (including the catheter near the skin), and draping typical of a procedure done in a surgical suite or outpatient surgery room (a drape to cover the primary incision, deliberately excluding the exit site, since the exit site and catheter, even when treated with antiseptic, cannot be considered clean). Here too, an operating room is not needed as the procedure can be performed in a procedure room using standard precautions for infection control.

Removal of Missouri or Toronto–Western type catheters is a little more complicated, since the Dacron disc rests next to the peritoneum and develops fibrous adhesions to the peritoneum and the posterior rectus sheath. These catheters are generally placed by surgeons and should be removed by the surgeons who placed them.

A variety of issues surround the procedure for PD catheter insertion. These include migration of a catheter, placement of a catheter in a patient with prior abdominal surgery, and bowel perforation following insertion of a PD catheter.

Visceral Perforation

Bowel perforation is the most feared complication of peritoneoscopic insertion of a PD catheter and is the most important factor preventing nephrologists from performing this procedure. Although the risk of bowel perforation following insertion of a PD catheter is minimal, nephrologists performing this procedure should be well versed in diagnosing this complication promptly and managing the patient effectively.

The true incidence of bowel perforation with the peritoneoscopic technique is unknown. A recent study evaluating 750 PD catheter insertions performed by nephrologists utilizing the peritoneoscopic technique found the incidence of this complication to be 0.8%. However, numerous other studies do not report a single episode of bowel perforation. In contrast, the incidence of visceral perforation using the dissective technique has been reported to range from 1% to 1.4%. Whereas some investigators suggest that this complication should be treated with surgical intervention, successful conservative management of bowel perforation using bowel rest and intravenous antibiotics has also been reported.

Introduction of a trocar (diameter 2.2 mm) into the abdominal cavity is likely responsible for bowel injury when a PD catheter is inserted using the peritoneoscopic technique. Bowel injuries due to the introduction of insufflation needles, trocars, rigid catheters, and colonoscopic examinations have been reported. The majority of these perforations are usually small and seal spontaneously. These “miniperforations” close within 24–48 hours, most likely secondary to omental adherence. The majority of small perforations are self-sealing and do not require surgical intervention.

In summary, the peritoneoscopic technique of PD catheter insertion allows the nephrologist to make the diagnosis of bowel perforation immediately and implement therapeutic measures promptly. Nephrologists can successfully manage these patients conservatively with close monitoring of vital signs, serial abdominal examination, bowel rest, and broad spectrum intravenous antibiotics. With this approach patients who do not need surgical intervention can be identified and unnecessary laparotomy can be avoided. Clinical deterioration and signs of peritoneal irritation should prompt a surgical consult.

Migration and Repositioning

PD catheter migration to the upper abdomen is not uncommon (15–35%) and usually leads to outflow problems and catheter failure. The condition is suspected by encountering flow problems and is confirmed by plain abdominal X-ray. A variety of techniques have been used to combat migration with long-term success rates of 27–48%.

Previous Abdominal Surgery

A history of previous abdominal surgery could result in significant intraperitoneal adhesions and has been identified as a relative contraindication to PD. Nevertheless, catheter insertion can be successfully accomplished in this population; a history of abdominal surgery does not necessarily increase the risk of bowel perforation. The common notion that “patients with previous abdominal surgery are not the best candidates for peritoneal dialysis” should be discouraged. Since the peritoneoscopic technique identifies intraperitoneal adhesions, assesses their extent, and determines a suitable site for catheter placement, patients with a history of prior abdominal surgery should not be routinely denied this modality (Figure 58–5). PD catheter insertion can be successfully performed in this population with a high rate of success (>95%).

Underutilization

PD is an underutilized form of renal replacement therapy. Only 12% of patients with ESRD utilize this form of dialysis in the United States. A variety of factors have been deemed responsible. Of these, modality choice presentation followed by swift catheter insertion is of critical importance. Unnecessary delays in catheter insertion may leave patients who choose PD with a modality that they did not desire. At least two separate studies have documented a positive impact of PD access surgery by nephrologists on underutilization of PD.

PD access-related procedures can be safely and successfully performed by nephrologists with excellent catheter outcome data. There are a variety of advantages, including the timely initiation of therapy, when the catheter insertion is performed by a nephrologist. However, nephrologists must obtain optimal training and develop the necessary skills to perform these procedures. ASDIN is actively engaged in promoting the performance of PD access-related procedures by nephrologists and developing training centers at academic medical centers. At every dialysis center, selected nephrologists should consider expanding their role to perform PD access-related procedures in order to provide timely delivery of this aspect of ESRD care.