Tenckhoff Catheter Research Articles

腹膜透析カテーテル抜去に伴い生じた下腹壁動脈損傷に直視下止血術で対応した1例

症例は85歳女性. 6年前に経腹直筋アプローチで挿入された腹膜透析カテーテルを抜去した3時間後, 抜去創の直下に直径10cmを超える巨大皮下腫瘤が出現した. 手術室で創部の再解放が行われ, 下腹膜動脈断端からの出血が確認されたため, 結紮止血および血腫吸引が行われた. その後の経過は順調であった. 経腹直筋アプローチで挿入された腹膜透析カテーテルを抜去する際には, 下腹壁動脈損傷の可能性を念頭に置く必要がある.

Inferior epigastric artery: Surface anatomy, prevention and management of injury.

The anatomical position of the inferior epigastric artery (IEA) subjects it to risk of injury during abdominal procedures that are close to the artery, such as laparoscopic trocar insertion, insertion of intra-abdominal drains, Tenckhoff(®) catheter (peritoneal dialysis catheter) and paracentesis. This article aims to raise the awareness of the anatomical variations of the course of the IEA in relation to abdominal landmarks in order to define a safer zone for laparoscopic ancillary trocar placement. Methods of managing the IEA injury as well as techniques to minimise the risk of injury to the IEA are reviewed and discussed.

Few Outflow Problems With a Self-locating Catheter for Peritoneal Dialysis: A Randomized Trial.

We developed a technique for direct start of peritoneal dialysis. Using a coiled or straight Tenckhoff catheter often results in obstruction of flow. A self-locating Wolfram catheter is on the market. It is not clarified if this results in a benefit.The primary aim of this study was to perform a randomized investigation to clarify if the use of a self-locating peritoneal dialysis (PD) catheter would result in different flow problems than a straight Tenckhoff catheter.A total of 61 insertions were made who were randomized and received either a straight Tenckhoff (n = 32) or a self-locating Wolfram catheter (n = 29).A previously described operation technique allowed immediate postoperative start of dialysis. Seven straight Tenckhoff catheters had to be changed into self-locating catheters, and none vice versa, due to flow problems (P = 0.011). An early leakage resulted in temporarily postponed PD in 4 patients.This study showed that using the present operation technique the self-locating PD-catheter causes fewer obstruction episodes than a straight Tenckhoff catheter. This facilitates immediate postoperative start of PD.

Simultaneous abdominal wall defect repair and Tenckhoff catheter placement in candidates for peritoneal dialysis.

IntroductionThe presence of pre-existing abdominal wall defect (AWD) could represent a potential contraindication for peritoneal dialysis (PD) treatment. We report the results of our 6-year experience involving simultaneous repair of pre-existing AWD and catheter insertion for PD.MethodsPatients with estimated glomerular filtration rate (e-GFR) 7–10 ml/min attending a single nephrology clinic between January 2008 and December 2014 were evaluated. Simultaneous AWD repair and catheter placement was performed. For inguinal (IH) or umbilical hernia (UH), a prolene mesh repair technique was adopted. Except for one case of total anaesthesia, the surgical procedure was performed under either spinal or local anaesthesia. Ceftazidime alone or in association with quinolones was administered 1 h before surgery in a single dose. Patients were discharged 2 days after surgery, and returned to the clinic twice during the 1st week for peritoneum washing (first volume of peritoneal dialysis solution: 300 ml). From week 3, volume (2000 ml) and dwells were personalized according to the patient’s clinical condition; options were: incremental PD, standard PD, or continuous cycling PD. Surgical follow-up was planned at 1, 6, and 12 months.ResultsPeritoneal catheters were inserted in 170 patients. IH, UH and incisional hernia were found in 18, 2 and 1 patients, respectively. IH was bilateral in 4 patients; concomitant IH and UH occurred in 1 patient. There were no deaths, nor intra-operative complications apart from scrotal haematoma in 1 patient. Over a mean follow-up of 551 days (range 342–1274) no hernia recurrence was registered and the peritoneal catheter continued functioning without problems.ConclusionsSimultaneous AWD repair and peritoneal catheter placement seems a reliable and safe surgical procedure that allows patients with AWD to benefit from PD treatment.

Vertical Tunnel-based Low-site Peritoneal Dialysis Catheter Implantation Decreases the Incidence of Catheter Malfunction

Peritoneal dialysis (PD) is often complicated by catheter dysfunction. We designed a PD catheter implantation technique to reduce catheter dysfunction. Between June 2008 and 2012, 89 patients with end-stage renal disease were enrolled into a prospective study and randomly assigned to receive traditional catheter implantation by open surgery (n = 41) or vertical tunnel-based low-site PD catheter implantation (n = 48). Both procedures used Baxter straight double-cuffed Tenckhoff catheters. The novel implantation technique involves a low-site (7 cm above the midpoint of the pubic symphysis), individually tailored intra-abdominal segment, and increased vertical subcutaneous tunnel. Patients were followed for 1-year after procedure. The vertical tunnel-based low-site method implanted catheters were 3.7 ± 0.9 cm long, with an 11.3 ± 0.9 cm intra-abdominal segment. The incidence of postoperative bleeding, PD fluid leakage, outer cuff extrusion, inflow or outflow pain, peritonitis, tunnel inflammation, or exit-site infection did not differ significantly between the two surgical techniques; however, the incidence of catheter displacement and noncatheter displacement malfunctions after the novel technique (4.2%) was significantly lower than that in traditional open surgery (19.5%, P < 0.05). In conclusions, vertical tunnel-based low-site PD catheter implantation can significantly reduce the occurrence of PD catheter malfunction, particularly catheter displacement.

Pelvic drainage during removal of dialysis catheter decreases the risk of subsequent intra-abdominal complications in refractory peritoneal dialysis-related peritonitis.

Some patients with refractory peritoneal dialysis-related peritonitis continue to develop intra-abdominal complications despite removal of the peritoneal catheter. Repeated percutaneous drainage or open laparotomy is often required, and mortality is not uncommon. The benefits of pelvic drainage placement during catheter removal in decreasing these complications and interventions remain unproven. Forty-six patients with refractory peritonitis who underwent removal of a Tenckhoff catheter between 1991 and 2013 were reviewed retrospectively. Twelve patients had pelvic drainage using closed active suction devices during catheter removal (drainage group). The remaining 34 patients underwent catheter removal without drainage (non-drainage group). The outcomes measured were the development of intra-abdominal complications and the requirement for repeated percutaneous drainage or open laparotomy within 90 days after the catheter removal. Baseline characteristics were similar with the exception of a higher median number of previous peritonitis episodes in the drainage group compared with the non-drainage group (2 vs 0, P = 0.02). During the follow-up period, intra-abdominal complications occurred in 15 (44%) of 34 patients in the non-drainage group, compared with one (8%) of 12 patients in the drainage group (P = 0.03). Twelve (35%) patients in the non-drainage group required repeated percutaneous drainage or open laparotomy for management, compared with zero (0%) patients in the drainage group (P = 0.02). Drain tubes were removed at a median of 6 days (inter-quartile range: 5-10) without complications. In the management of refractory peritonitis, pelvic drainage during removal of dialysis catheter decreases the risk of subsequent intra-abdominal complications and invasive interventions.

Comparing the Incidence of Catheter-Related Complications with Straight and Coiled Tenckhoff Catheters in Peritoneal Dialysis Patients—a Single-Center Prospective Randomized Trial

♦ We aimed to prospectively compare the incidence of catheter-related complications and catheter survival for straight (SCs) and coiled (CCs) Tenckhoff catheters in peritoneal dialysis (PD) patients. ♦ This open prospective randomized trial recruited 189 PD patients with end-stage renal disease from the department of nephrology, The First Affiliated Hospital of Sun Yat-sen University from 6 November 2007 to 27 August 2008. The patients were randomized to a SC (n = 99) or a CC (n = 90) and were then followed for 2 years. All catheter placements were performed by two designated experienced nephrologists who used a standardized institutional placement protocol. The primary study outcomes were catheter-related complications and catheter survival at 1 and 2 years. ♦ We observed no significant differences in clinical and demographic characteristics between the groups at baseline. The overall incidence of catheter dysfunction was higher in the CC group than in the SC group (17.8% vs 7.1%, p = 0.03), and most of the events occurred 4 weeks or more after the catheters were implanted. Catheter tip migration and omental wrapping were the most common causes of catheter dysfunction. Surgical catheter rescue was more common in patients with CCs than in patients with SCs (9 vs 3 patients respectively, p = 0.05). No significant differences were observed in other catheter-related complications, including dialysate leaks, hernias, and PD-related infections (peritonitis, exit-site, and tunnel infections). Catheter survival rates in the SC and CC groups were similar at 1 year (96.7% ± 1.9% vs 96.5% ± 2.0%, p = 0.98) and at 2 years (95.3% ± 2.3% vs 92.4% ± 3.6%, p = 0.76). ♦ The incidence of PD catheter-related complications is probably higher with CCs than with SCs. The results of our study suggest that a SC is the better option to reduce subsequent catheter complications.

Amputation of the peritoneal dialysis catheter in the abdominal cavity

An 83-year-old female patient with a 3-year history of peritoneal dialysis (PD) for diabetic nephropathy presented to our clinic with abrupt dialysate drainage failure. The Tenckhoff catheter inserted 3 years ago was a two-cuffed, straight-type flexible silicone tube. Before presentation, she had no abnormal sensation in the abdomen, had not performed any vigorous exercises, or received external force to the abdomen that could have caused catheter damage. No crack or fracture was observed in the PD catheter outside the exit site.

Viridans Streptococci in Peritoneal Dialysis Peritonitis: Clinical Courses and Long-Term Outcomes

The clinical courses and long-term outcomes of viridans streptococcus (VS) peritoneal dialysis (PD) peritonitis remain unclear. We conducted a retrospective analysis of all PD patients in a single center with gram-positive cocci (GPC) peritonitis between 2005 and 2011, and divided them into 3 groups: VS, other streptococci and other GPC (apart from VS). Clinical characteristics and outcomes of the VS group were compared with the other streptococci and other GPC groups, with prognostic factors determined. A total of 140 patients with 168 episodes of GPC peritonitis (44% of all peritonitis) were identified over 7 years. Among these, 18 patients (13%) developed VS peritonitis, while 14 patients (10%) developed other streptococcal peritonitis. Patients with VS peritonitis had a high cure rate by antibiotic alone (94%), despite a high polymicrobial yield frequency (28%). We found that VS peritonitis carried a lower risk of Tenckhoff catheter removal and relapsing episodes than other GPC peritonitis (6% vs 11%), and a lower mortality than other streptococci peritonitis (0% vs 7%). However, after the index peritonitis episodes, VS, other streptococci, and other GPC group had a significantly increased peritonitis incidence compared with the period before the index peritonitis (all p < 0.01). Patients with VS peritonitis had a significantly higher incidence of refractory peritonitis compared with other streptococci or other GPC peritonitis in the long term (both p < 0.01). VS poses a higher risk of subsequent refractory peritonitis after the index episode as compared with other streptococcal or GPC peritonitis. It might be prudent to monitor the technique of these patients with VS peritonitis closely to avoid further peritonitis episodes.

Complications associated with 9–10 Fr venous access port use in adjuvant intraperitoneal chemotherapy after a cytoreductive surgery in ovarian cancer patients

PurposeTo determine the complication rate associated with using a single-lumen intravenous access port with a silicone catheter of 9–10Fr size in the intraperitoneal treatment, including hyperthermic intraperitoneal chemotherapy, in ovarian cancer. Patients/methodsWe reviewed 27 patients who had subcutaneous venous access ports placed for the administration of IP chemotherapy. With four patients, the catheter was implanted during a hyperthermic intraperitoneal chemotherapy-related laparotomy using the closed technique. Each case was categorized as to the number of cycles of IP therapy received. ResultsSeven catheter-related complications were noted. These were divided into two categories: six malfunctions (24%) and one infection (4%). Overall, of the patients who had IP catheters placed and received IP chemotherapy, 13 (54.2%) were able to complete the six regimens. Among the four (14.8%) patients who had the catheters planted directly following the HIPEC, one experienced a catheter leak, one an infection and one concluded the treatment successfully; one is still being treated. ConclusionsA subcutaneous single-lumen intravenous access port with a silicone catheter of a large size (9–10Fr) is related to a lower rate of catheter-related complications than previously reported open-ended Tenckhoff catheter treatment. An additional advantage is the possibility of removing the catheter as an office procedure under local anesthesia. Intraperitoneal chemotherapy following a HIPEC procedure may cause increased occurrence of catheter-related complications. As of 2010 we have been using silicone subcutaneous catheters in our center.

The Use of Tenckhoff Catheters for Draining of Symptomatic Lymphoceles: A Review of Literature and Our Experience

BackgroundLymphoceles are one of the common complications of kidney transplantations. While small, asymptomatic lypmhoceles do not require intervention, however, larger, high-pressure cases can lead to graft dysfunction and are thus an indication for decompression. The aim of this study is to present the drainage using a Tenckhoff catheter as effective treatment for recurrence of symptomatic lymphoceles based on both a single center's experience as well as existing literature. Materials and MethodsIn our database, two patients were operated with a Tenckhoff catheter for the recurrence of symptomatic lymphocele. A review of MEDLINE in search of cases with lymphoceles treated with Tenckhoff catheterization yielded only five articles published between 1990 and 2014. The reports covered 15 cases in which 11 patients were treated for a primary lymphocele whereas 4 were treated for a recurring lymphocele. ResultsThere was no evidence of lymphocele recurrence or infections after Tenckhoff catheterization in either the material review or our database. ConclusionsIntraperitoneal drainage with a Tenckhoff catheter seems to be an effective and safe method for treating recurrent, symptomatic lymphoceles after renal transplantation.

Kocuria Species Peritonitis: Although Rare, we Have to Care

Kocuria species are found in the environment and on human skin. These micro-organisms are generally considered to be nonpathogenic saprophytes, rarely causing infection. However, the peritoneum has been reported to be a site of Kocuria infection. We reviewed all cases of peritonitis in peritoneal dialysis (PD) patients caused by Kocuria species that were reported in the worldwide literature. In total, 12 episodes of Kocuria species peritonitis have been reported in 9 PD patients. The median age of the patients was 62 years (range: 8 - 78 years). In the reported episodes, 4 different Kocuria species were isolated, with K. varians being the predominant species (41.7%). The most common initial symptom was abdominal pain (83.3%), followed by turbid effluent (75%) and fever (33.3%). Intraperitoneal first-generation cephalosporins and glycopeptides were the most-used antibiotics, with first-generation cephalosporins being more often preferred as first-line therapy. The median duration of treatment was 14 days, and in 2 episodes, the Tenckhoff catheter was removed. Although Kocuria peritonitis in PD patients is rare, it should be promptly treated because relapses can occur, especially with K. varians episodes.

Modified laparoscopic technique for fixation of peritoneal dialysis catheter.

Continuous ambulatory peritoneal dialysis (CAPD) is a treatment for patients with end-stage renal disease (ESRD). Peritoneal dialysis catheters are usually placed using a small laparotomy. This traditional technique is usually safe if well executed, but it cannot be safely performed if the patient has had a previous abdominal operation. A minimally invasive procedure may progress safely by laparoscopic intervention. However, dysfunction of the catheter during a laparoscopic intervention is a common complication related to CAPD. This usually involves intra-abdominal migration of the catheter, even with one intra-abdominal fixation. In an effort to increase catheter survival, we tested a modified laparoscopic technique with two intra-abdominal fixations of a Tenckhoff catheter. Forty-one consecutive ESRD patients (mean age, 53.4 y; range, 31 to 84 y) underwent modified laparoscopic Tenckhoff catheter implantation with 2 intra-abdominal fixations between September 2009 and January 2013. The same perioperative protocol and surgical technique were used in all patients. Another 49 ESRD patients who had received laparoscopic Tenckhoff catheter implantation with 1 intra-abdominal fixation performed by the same surgeon were retrospectively recruited for comparison. The modified laparoscopic procedure with two intra-abdominal fixations of a Tenckhoff catheter was successfully performed in all patients. The mean operating time was 24.3 minutes (range, 15 to 37 min). The mean blood loss was 5.6 mL (range, 5 to 20 mL). Catheter survival was 100% until February 2013. No major perioperative complications were found. A Kaplan-Meier Survival Analysis found no significant difference between the 2 groups in sex, age, operative time, or blood loss. The catheter survival rate was significantly higher in the patients with two intra-abdominal fixations. Most patients were satisfied with the functional results of the Tenckhoff catheter. The laparoscopic 2-site fixation technique is an effective and safe procedure but long-term follow-up and more cases are necessary.

Is there need of an extension channel/new double-cuffed channel in surgical management for channel perforation and aneurysm of Tenckhoff catheter?: modified partial replantation.

Is there need of an extension channel/new double-cuffed channel in surgical management for channel perforation and aneurysm of Tenckhoff catheter?: modified partial replantation.

Peritoneal‐dialysis related peritonitis caused by Gordonia species: Report of four cases and literature review

To investigate the clinical course and outcome of peritoneal dialysis-associated peritonitis secondary to Gordonia species. We reviewed all Gordonia peritonitis episodes occurring in a single dialysis unit from 1994 to 2013. During the study period, four episodes of Gordonia peritonitis were recorded. All were male patients. One patient responded to vancomycin therapy. One patient had refractory peritonitis despite vancomycin, but responded to imipenem and amikacin combination therapy. One patient had relapsing peritonitis and required catheter removal. The fourth patient had an elective Tenckhoff catheter exchange. No patient died of peritonitis. Causative organism was not fully identified until 7 to 18 days of peritonitis. Gordonia species is increasingly recognized to cause serious infections. In patients undergoing peritoneal dialysis, Gordonia peritonitis should be considered in case of refractory Gram-positive bacilli peritonitis, especially when the exact organism could not be identified one week after the onset of peritonitis. A close liaison with a microbiologist is needed for a timely diagnosis.

A modified open surgery technique for peritoneal dialysis catheter placement decreases catheter malfunction.

This retrospective study was conducted to evaluate the effect of a new, modified open surgery technique on catheter-related malfunction. During the period from January 1997 to June 2009, 216 patients received initial peritoneal catheters. For the present study, patients were divided into four groups according to the catheter types and the surgery techniques: TO-S: traditional open surgery, straight Tenckhoff catheter TO-C: traditional open surgery, coiled Tenckhoff catheter TO-SN: traditional open surgery, swan-neck catheter MO-S: modified open surgery, straight Tenckhoff catheter The modified surgery was characterized by a low incision site, a short intra-abdominal catheter segment and an additional upward straight subcutaneous tunnel. All patients were followed up for 2 years or until death. Survival rates, complications caused by catheter placement, and the probability of malfunction-free catheter survival were compared between the groups. Catheter malfunction was the most frequent mechanical complication, found in 31 patients (14.4%), who experienced 38 malfunctions. Only 2 episodes of catheter malfunction were found in the MO-S group, representing a rate significantly less than those in the TO-S and TO-C groups (both p < 0.05). Kaplan-Meier curves for malfunction-free PD catheter survival showed a significantly different malfunction-free probability for the various groups (p = 0.009). After 2 years of follow-up, 136 patients (63.0%) survived with their initial PD catheter. The initial catheter survival rate was 76.8% in the MO-S group. Kaplan-Meier curves for initial catheter survival showed that the highest survival rate was found in the MO-S group (p = 0.001). The modified open surgery technique is a reliable method for catheter placement.

Pet-related peritonitis and its prevention in peritoneal dialysis: a case study.

Infectious peritonitis is a major complication of peritoneal dialysis (PD), accounting for considerable mortality and morbidity of PD patients. Although the usual organisms associated with peritonitis are Staphylococci aureus, Staphylococci epidermidis, Pseudomonas species and other gram-negatives, peritonitis due to zoonotic organisms in the context of close contact with companion animals has been reported in literatures (1-12). On a literature review, 124 cases of peritonitis caused by 12 different zoonotic agents have been reported in PD patients. Thirty of them were following documented contacts with an animal with overall mortality of 13.5% (1). In 27% of the cases, the Tenckhoff catheter had to be removed (1). Pets are very popular in our society with 63% of households in the United States (2,3) and 45% in Europe (1) with at least one pet, dogs and cats being more popular (2). Evidence-based literature suggests that animals/pets are a life-time companion and can help a person better cope with stressful life events, provide psychological help for the isolated or elderly, decrease depression, improve activities of daily life and increase social interaction. Pets are considered part of the family in many households and have very close contacts with their owners. However, close contact with pets is one of the major risk factors for peritonitis caused by zoonotic organisms (4). In our dialysis unit, we also encountered a patient who had close contact with cats with 3 episodes of peritonitis due to Pasteurella multocida over a 6-month period. This prompted us to evaluate the prevalence of pets and pets-related peritonitis in our peritoneal dialysis patients, and to assess the impact of a training session on pet-related peritonitis.

Different outcomes of peritoneal catheter percutaneous placement by nephrologists using a trocar versus the Seldinger technique: the experience of two Brazilian centers.

A good catheter implantation technique is important to allow effective peritoneal access function and long-term technique survival. Studies regarding results obtained by nephrologists in comparison with different techniques have been limited. The aim of this study was to investigate the rate of early catheter-related complications and catheter survival in two Brazilian centers, according to two different percutaneous methods of catheter implantation performed by nephrologist team. Adult incident patients recruited from January 2006 to July 2013 having undergone first peritoneal dialysis (PD) catheter implantation were included in the analysis. Mechanical and infectious early complication rates were defined as time to the first event occurring up to 3 months. Four hundred and forty-five consecutive Tenckhoff catheters were implanted by nephrologist team percutaneously after antibiotic prophylaxis in an operating room: trocar was used in 349 (78.4 %) and Seldinger technique (ST) in 99 (21.6 %). The ST was significantly associated with a lower rate of leak (16.3 vs 3 %, p = 0.03) and outflow failure due to tip catheter migration (22.6 vs 10.1 %, p = 0.04), while early infectious complication rates were similar between the two groups (p = 0.59). Long-term catheter survival was higher in Seldinger group (log-rank, p = 0.031). By Cox multivariate analysis, adjusted for age, sex, and diabetes, the ST remained independently associated with better catheter survival [HR 0.681 (0.462-0.910), p = 0.04]. As conclusion, our experience showed better PD outcomes with the ST than trocar method of catheter implantation by nephrologist.

Mycobacterium fortuitum and Polymicrobial Peritoneal Dialysis-Related Peritonitis: A Case Report and Review of the Literature.

Mycobacterium fortuitum is a ubiquitous, rapidly growing nontuberculous mycobacterium (NTM). It is the most commonly reported NTM in peritoneal dialysis (PD) associated peritonitis. We report a case of a 52-year-old man on PD, who developed refractory polymicrobial peritonitis necessitating PD catheter removal and shift to hemodialysis. Thereafter, M. fortuitum was identified in the PD catheter culture and in successive cultures of initial peritoneal effluent and patient was treated with amikacin and ciprofloxacin for six months with a good and sustained clinical response. Months after completion of the course of antibiotics, the patient successfully returned to PD. To our knowledge, this is the first reported case of M. fortuitum peritonitis in the field of polymicrobial PD peritonitis. It demonstrates the diagnostic yield of pursuing further investigations in cases of refractory PD peritonitis. In a systematic review of the literature, only 20 reports of M. fortuitum PD peritonitis were identified. Similar to our case, a delay in microbiological diagnosis was frequently noted and the Tenckhoff catheter was commonly removed. However, the type and duration of antibiotic therapy varied widely making the optimal treatment unclear.

Urgent Peritoneal Dialysis Initiation: is it Better to Wait a Few Days than to Use the Catheter Immediately After its Implantation? A Randomized Controlled Trial

Background: High-grade evidence for recommendations about the appropriate lag-time from implantation to utilization of the catheter regarding urgent PD is lacking. The objective of this study was to compare immediate and delayed utilization of the Tenckhoff catheter in urgent PD. Methods: 160 patients beginning urgent automated peritoneal dialysis (APD) were randomized into two groups of 80 patients each. In the immediate utilization group (I), the catheter was used immediately after the surgical implantation; in the delayed utilization group (D), the catheter began to be used 3-5 days after the surgical implantation. The catheter function and complications in the two groups were compared after a one-year follow-up. Results: Patients in I and D were aged 42.5±18.5 and 49.2±19.6 years and their BMI was 25±2.5 and 25±3 kg/m2, respectively. The lag-time from implantation to utilization of the catheter was shorter in I (4±2 h) than in D (79.5±35.7 h; p < 0.01). Both groups had similar frequency of overall complications: 10 patients (12.5%) in I and 12 patients (15%) in D developed catheter related complications within 12 months. Group I complications were leakage (2), migration (2), and peritonitis (2); group D complications were leakage (3), migration (4), and peritonitis (2). Actuarial survival of the catheter showed no differences between the two groups at one year. Conclusions: Immediate utilization of a surgically implanted Tenckhoff catheter is feasible and safe, since it is not associated with an increased frequency of complications.