Peritoneal dialysis (PD): access

Catheter and exit site selection

Catheter selection

• Intraperitoneal configurations (i.e., catheter tip): straight vs curled
  • No data support one over the other, but good reason to use the curled catheter whenever possible
    • Curled catheter is larger and may be difficult for babies to accommodate, so straight catheter often used in neonates
• Cuffs: one vs two
  • Two cuffs may decrease infection rate
    • This difference may be attenuated by the regular use of exit site antibiotics (infection rates may be equivalent)
  • Cuff extrusion (with double cuff) increases infection risk
    • Can occur if large amounts of tension on the catheter (e.g., large catheter in small patient, excessive catheter bend) and/or if thin abdominal wall (e.g., babies, malnourished), so single cuff often used in neonates
• Extra-peritoneal configuration: straight vs swan neck
  • Pre-bent swan neck catheter ensures downward facing exit site which reduces risk of infection
  • If swan neck catheter not available in appropriate size, can use three incisions to more gently curve a straight catheter
  • Swan neck catheter has superior technique survival [Biblaki et al., 2015]

Catheter exit site

• Downward direction reduces infection risk
  • If downward (i.e., inferior/caudal) not possible, then lateral
  • Never upward (i.e., superior/cranial)
    • Tenting of the skin at the exit site creates a little upward-facing cup that allows for things (e.g., bacteria) draining by gravity to pool at the exit site, greatly increasing the risk of infection
• Away from stomas and G-tubes (or future G-tubes)
• Exit site should be ~2 cm from subcutaneous (outer) cuff
  • If >2 cm, epithelium cannot grow up to the cuff and granulation tissue will form, increasing infection risk
  • If <2 cm, increased risk of catheter extrusion
• Catheter should be fixed securely
  • Avoid the use of sutures at the exit site
    • Can result in ischemia of skin or foreign body reaction
  • If not secured, movement of the catheter can lead to granulation tissue

Best practices

• Bowel regimen to prevent perioperative constipation, which can make catheter positioning difficult and displace the catheter postoperatively
• Empty bladder before procedure; otherwise, Foley catheter should be inserted
• Single preoperative dose of IV antibiotic to provide antistaphylococcal coverage
• Paramedian insertion of PD catheter through the body of the rectus muscle with deep duff within or below the muscle fibers
• Pelvic position of the catheter tip
  • Upper part of the true pelvic bowl
  • Majority of dialysate pools in the pelvic region
• Purse string suture to prevent leaks
• Subcutaneous tunneling instrument does not exceed diameter of the catheter
• Flow test to confirm function
• Exit site ≥2 cm beyond superficial cuff
  • Minimize risk of extrusion
  • Minimize risk of involvement of the cuff if there is an exit site infection
• No catheter anchoring sutures
  • Predisposes to early exit site and tunnel infection
  • If noted to be present after surgery, they should be removed
• Non-occlusive dressing
  • Occlusive dressing can macerate exit site or insertion incision

Early exit site care

• Dressing changes should be avoided in the first week after catheter placement, then performed weekly by experienced
  PD
  staff until the site is well healed
  • Avoid additional dressing changes unless dressing becomes soiled/wet
  • Healing typically takes 2-3 weeks but can take up to 6 weeks
• Avoid showering/bathing during the healing phase

Dressing change technique

• Use an aseptic technique, including sterile gloves and face mask
• Clean around the site with sterile gauze soaked in sterile cleansing solution (e.g., chlorhexidine, saline, or Shur-Clens)
  • Avoid using irritating cytotoxic agents such as povidone iodine or hydrogen peroxide
  • Do not forcibly remove any crusts
• Use another piece of soaked gauze to clean the tubing, starting with the exit site and working up the tubing away from the body
• Pat the exit site dry with gauze and ensure it is completely dry
  • Some centers will apply an antibiotic ointment (e.g., gentamicin, mupirocin, Medihoney) during dressing changes
    • Only a small amount (e.g., pea sized) is necessary
      • Excessive ointment is wasteful and can crust on the dressing, confusing exit site assessment
    • Do not use ointments containing polyethylene glycol as this can degrade the polyurethane catheter
• Allow the catheter to fall to its natural position
• Completely cover the exit site with several layers of sterile gauze and secure with a dressing
• Immobilize the catheter below the exit site dressing, anchoring the tube to restrict movement
  • Commercially available immobilization devices may be used, but tape or a dressing are also adequate

PD catheter insertion techniques

Selecting an insertion technique

• Two techniques may be used: advanced laparoscopic or open dissection

Principles of catheter insertion

• Create an oblique, watertight subcutaneous tunnel through the abdominal wall
  • Oblique (rather than straight) path through the abdominal wall reduces the risk of hernia and leak
• Position the tip in the pelvis
• Do an omentectomy when possible to help reduce the risk of early catheter failure [PMID 20223324]
  • Relatively simple for both open and laparoscopic technique
• Laparoscopy preferred over open
  • Data is becoming more convincing that laparoscopic is generally superior to open technique [PMID 19306986]
    • Better flow
      • Easier to achieve optimal catheter position
    • Longer catheter life
      • May be because of lower rate of adhesion formation with laparoscopic technique
    • Ability to perform additional surgeries (e.g., hernia repair)
• Deep cuff secured in the muscle between anterior and posterior sheaths of the abdominal rectus
• Regardless of whether laparoscopic or open technique is used, the subcutaneous tissue should be smaller than the catheter
  • Do not use a hemostat to push the catheter through; hemostats have a wide triangular shape that will widen the tunnel when pushed through
  • Use Steinmann pin or can use peel-away sheath with guidewire (Seldinger technique)
• Exit site should be as small as is feasible
  • Can use skin punch biopsy to make the incision (round hole for round catheter helps minimize the hole size)