Peritoneal dialysis, as an important renal replacement therapy for end-stage renal failure, has been widely used in clinical practice. With the improvement of external device materials and connection technology, the improvement of catheter placement technology and the application of new peritoneal dialysis fluids, complications have been reduced and the success rate and efficacy of peritoneal dialysis have been greatly improved. However, complications associated with peritoneal dialysis catheters still plague clinicians. Since the introduction of peritoneal dialysis catheters in the 1960s, Tankhoff catheters, TWH catheters, and gooseneck catheters have appeared appeared one after another. With the emergence of various new catheters, catheter-related complications have gradually decreased, improving the prognosis of peritoneal dialysis and promoting the development of clinical peritoneal dialysis. However, recent studies have shown that peritoneal dialysis catheter-related complications still account for nearly 20% of the reasons for conversion of peritoneal dialysis to hemodialysis. It is evident that peritoneal dialysis catheter-related complications still affect the long-term prognosis of patients. Peritoneal catheters play an important role in peritoneal dialysis treatment and are the "lifeline" of peritoneal dialysis patients. The quality of the catheter determines the success or failure of peritoneal dialysis. Common complications of peritoneal catheters include peritonitis, skin outlet and tunnel infections, and floating tubes. Different types of catheters have different characteristics. The advantages and disadvantages of commonly used clinical peritoneal dialysis catheters are introduced for better clinical application.
1. Comparison of the effects of single-cuffed catheters and double-cuffed catheters on peritonitis
Tenckhoff catheters and gooseneck catheters both have a sleeve structure, including a single sleeve and a double sleeve. The sleeve structure is made of polyester, which is an important structure for peritoneal dialysis catheters. Within a month of implantation in the abdominal wall, the sleeve stimulates the growth of large amounts of fibrous tissue and granulation. The two are tightly integrated and serve to secure the catheter and close the tunnel while preventing invasion by pathogenic microorganisms. Early clinical studies have shown that first peritonitis occurs later with double-sleeved bursal catheters than with single-sleeved catheters, and that tunnel infection is less likely than with single-sleeved catheters. In recent years, a cohort study involving 4,247 patients on continuous ambulatory peritoneal dialysis (CAPD) at 25 peritoneal dialysis centers in Canada compared the effect of double-sleeve Tenckhoff catheters and single-sleeve Tenckhoff catheters on the incidence of peritonitis in peritoneal dialysis patients from 1996 to 2005. The results showed that prior to 2001, the incidence of Staphylococcus aureus peritonitis in patients with double-jacketed Tenckhoff catheters was 54% lower than that in patients with single-jacketed Tenckhoff catheters, with a risk ratio for peritonitis of 0.46 (95% CI 0.33 to 0.64, P0.001), suggesting that double-jacketed Tenckhoff catheters have a better role in preventing the invasion of bacteria along the tunnels on the surface of the body. From 2001 to 2005, although the risk ratio of peritonitis associated with double-sleeve bursa catheters remained lower than that of single-sleeve bursa catheters, its incidence was not significantly different from that of single-sleeve bursa catheters (P=0.08). Analysis of the causes suggests that this is related to improved catheter tunnel exit care techniques, which have reduced infections in single-cuffed catheters. The study also showed that when the fixation position of the single cuff was moved from under the skin to the rectus abdominis muscle layer, the incidence of infection was significantly reduced, which was not significantly different from that of the double cuff catheter. The reason for this is that with the single cuff away from the skin, there is a lower incidence of skin injury and a lower incidence of infection at the tunnel exit; and the muscle tissue has a better environment for fiber growth than the subcutaneous connective tissue, which results in a tighter bond between the cuff and the muscle tissue and a better tunnel seal. The application of this method not only avoids the bouncing force generated by the bending of the catheter in the tunnel caused by the double cuff, but also reduces the incidence of skin damage and infection caused by the cuff. The results of meta-analyses in recent years have shown a significant decrease in the incidence of single-cuff catheter-associated peritonitis, and no significant difference in the incidence of double-cuff catheter-associated peritonitis versus double-cuff catheter-associated peritonitis. Typically, Staphylococcus aureus infects the subcutaneous tunnel through the catheter skin outlet and then infects the abdominal cavity. Advances in catheter skin outlet care concepts and infection prevention techniques have reduced S. aureus colonization and infection of skin outlets and tunnels, decreasing the incidence of catheter-associated infections. As a result, the incidence of S. aureus infections caused by single-cuffed catheters has decreased, and the mechanical barrier function of double-cuffed catheters has been relatively "weakened".
2. Comparison of the effects of Tenckhoff catheters and gooseneck catheters on tunnel-opening infections
In peritoneal dialysis, the shape of the straight Tenckhoff catheter determines that the skin exit can only be upward, and is therefore not conducive to perioperative drainage of fluids in the peritoneal wall tunnels. At the same time, due to the bowed shape of the subcutaneous tunnel, the subcutaneous sleeve of the catheter protrudes toward the skin under the rebound force of the curved catheter in the tunnel, and even the skin is damaged, all of which are risk factors for exit infection. The Gooseneck catheter improves on the shape of the Tenckhoff by changing the catheter between the double trocars to a permanent bend, which allows the catheter's cutaneous exit to face downward for drainage and eliminates the effect of the catheter's own rebound force, thus reducing the risk of infection at the exit and the risk of the catheter's abdomen floating due to rebound force. An RCT conducted in Hong Kong compared the effectiveness of straight Tenckhoff catheters and gooseneck catheters on skin outlet infections in 93 patients with CAPD.26 The 26-month results showed that the incidence of skin outlet infections and infection-induced extractions was lower for gooseneck catheters than for straight Tenckhoff catheters, but there was no significant difference, possibly related to the small sample size. However, in the comparison of the incidence of extubation due to S. aureus skin outlet non-nasal infections, the goose neck catheter was significantly lower than the straight Tenckhoff catheter, and the difference between the two groups was statistically significant (P=0.03). The results suggest that the gooseneck catheter has a better protective effect against S. aureus skin infections. In two RCT studies in Hong Kong and Macau, the traditional double-sleeve Tenckhoff straight catheter was inserted into the abdominal cavity through the U-shaped tunnel in the abdominal wall, and compared with the gooseneck catheter, and the results showed that there was no significant difference between the two in terms of the incidence of skin exit and tunnel infections (P=0.47, P=0.0657). This suggests that the U-shaped structure of the subcutaneous segment of the catheter is favorable for reducing skin damage and closing tunnels, and supports that the gooseneck catheter is better in preventing skin exit or tunnel infection.
A newly published meta-analysis including 5 RCT studies showed that compared with 313 CAPD patients with straight Tenckhoff catheters or gooseneck catheters, the RD (RiskDifference) for catheter skin exit and tunnel infections: 0.04) was 0.04 with a CI of -0.06 to 0.15, P=0.42 Peritonitis RD. 0.05, CI-0.06 to 0.16, P=0.34 Skin leakage at the tunnel exit RD:0.02, CI-0.03 to 0.07, P=0.40 That is, there was no significant difference in the risk of catheter-related complications between the two catheters. Results Good catheter and skin care techniques and effective infection prevention measures are important preventive tools to compensate for the associated complications caused by different catheter types.
3. Comparison of the effects of Tenckhoff straight and spiral catheters on intra-abdominal catheter drift.
Because of the different shapes of the abdominal segments of the catheter, straight catheters tend to be pushed or wrapped by the intestinal tubes or omentum, resulting in poor drainage, catheter floatation, and a higher incidence of catheter-induced abdominal pain than coiled catheters. Spiral catheters have relatively fewer of the above complications, but it is difficult to reset a spiral catheter by a guidewire after it has drifted. In a Danish RCT study, 72 patients with CAPD were randomized into two groups and then treated for 12 months with either a single-cuffed Tenckhoff spiral catheter or a straight catheter. Results The incidence of drainage obstruction with the curved catheter was 4/34 cases and with the straight catheter was 21/38 cases. The one-year survival rate was significantly higher for spiral catheters (77%) than for straight catheters (25%). At week 4, the survival rate of straight catheters had decreased to less than 50%, whereas the survival rate of coiled catheters had decreased by only 20%. The main reason for the decrease in catheter survival was the drift of the ventral segment of the catheter. That is, straight catheters have a significantly higher drift rate than coiled catheters. However, a meta-analysis of 1089 patients with CAPD from 1980 to 2004 showed no significant differences between straight and coiled catheters in terms of risk and morbidity of peritonitis, risk and morbidity of skin outlet infections, and risk of extraction and reimplantation. In a recent meta-analysis involving 7 clinical studies, the survival rates of intraperitoneal spiral and straight catheters were compared in 433 patients with CAPD. Incidence of cholera
In summary, the survival of dialysis catheters and the incidence of catheter-related complications vary because of the structure and shape of chronic peritoneal dialysis catheters. The survival time of gooseneck catheter is better than that of Tenckhoff catheter, the survival time of curved catheter is longer than that of straight catheter, and the survival time of double-cuffed catheter is even longer, i.e., double-cuffed gooseneck curved catheter is the most ideal. However, as dialysis technology and catheter care techniques improve, the incidence of catheter-related complications is decreasing, survival rates are improving, and the difference between the two is narrowing. Combined with a comprehensive price assessment, the double-cuffed Tenckhoff catheter remains the most commonly used peritoneal dialysis catheter in the country. Clinically, while focusing on different types of peritoneal dialysis catheters, more attention should be paid to catheter care and standardized peritoneal dialysis operations to reduce the occurrence of catheter-related complications.