Spontaneous knotting of urinary catheters placed with nonindwelling intent: Case series and literature review.

Urethral catheters are placed with nonindwelling intent chiefly for clean intermittent catheterization (CIC), imaging, or collection of a urine sample. Catheter knotting can be a troublesome complication, especially when it occurs in children often resulting in interventions under anesthesia in the operating room. Three children (4 years male, 4 years female, and 6 years male) presented with knotted feeding tubes placed for CIC. Details of these and an additional 31 patients are discussed in a short review. Knotting occurred almost exclusively in children (33/34, 97%), was more common in boys (22/34, 65%) and most often involved a feeding tube (27/34, 79%) with knotting in the bladder (28/34, 82%). Insertion length, caliber and stiffness of catheter, technique, and patient factors are important factors. Avoiding excessive insertion and use of an appropriate size of catheter (that is not too small) may reduce the risk. Manipulation alone (12/34, 35%), with guidewire (5/34, 15%), or with dilatation (3/34, 9%) is most often successful and is best accomplished under general anesthesia. Endourology (7/34, 21%), laparoscopy (1/34, 3%), or an incision (5/34, 15%) may be necessary in some patients. Safeguarding urethral integrity is the overarching concern. Copyright:

INTRODUCTION

Urethral catheters are placed with nonindwelling intent chiefly for clean intermittent catheterization (CIC), imaging, or collection of a urine sample. Catheter knotting can be a troublesome complication, especially when it occurs in children often resulting in interventions under anesthesia in the operating room. Such failure is different from failure to remove indwelling catheters. We present three patients with this problem and review the literature to suggest recommendations.

CASE REPORT

All three patients were children (4 years female, 4 years male, and 6 years male), who presented with failure to remove a catheter placed for CIC as a part of neurogenic bladder management. In one boy, catheter knotting occurred in the urethra [Figure 1], while the cause was intravesical knotting in the other two [Figures 2 and 3]. Gentle manipulation under general anesthesia was successful in two of the patients, while one 6-year-old male needed division of the catheter with cystoscopic extraction.

Figure 1

Knotting of clean intermittent catheterization catheter in the bladder of a 4-year-old girl operated in infancy for lumbosacral meningomyelocele. The 7F feeding tube could not be removed in the outpatient department. However, on gentle manipulation under general anesthesia, the knot detangled, and the catheter could easily be removed

Figure 2

Knotting of clean intermittent catheterization catheter in the urethra of a 6-year-old boy with neurogenic bladder due to lumbosacral meningomyelocele. The 6F feeding tube could not be removed under local anesthesia in the emergency room but could be removed after instilling copious amounts of lubrication under general anesthesia

Figure 3

A 4-year-old boy with a history of neurogenic bladder secondary to anorectal malformation. The 6F feeding tube got knotted in the bladder and could not be removed despite attempts at detangling under general anesthesia in the operating room. The meatal end was divided, and the catheter was pushed back into the bladder. The knot could be unraveled at cystoscopy using a grasper and the catheter was removed uneventfully

DISCUSSION

Failure of removal of a urethral catheter placed with nonindwelling intent is a sporadic problem that must be regarded as avoidable morbidity. It can be a frightening experience for children and their parents with potential implications for compliance with future CIC. A total of 29 publications representing 31 cases were identified using the PubMed search terms “catheter” and “knotting or entangl*” and secondary sources [Table 1].[1234567891011121314151617181920212223242526272829] We excluded patients in whom any type of catheter was placed with an indwelling intent. Failure to remove indwelling catheters are most often due to malfunction of the balloon.[30] Even when a nonself-retaining catheter is used, long dwell times and increased possibility of catheter migration that might permit knotting make these patients fundamentally different.

Table 1

Details of published case reports of knotting of catheters placed with nonindwelling intent including the current series of patients

Publication	Age, sex	Indication	Catheter size	Location of entanglement	Management
Harris, 1976	5 months, male	Imaging	8F, FT	Bladder	Manipulation with guide wire
Gaisie, 1983	10 months, female	Imaging	8F, FT	Bladder	Manipulation
Sugar, 1983	NA, female	CIC	8F, FT	Bladder	Manipulation
Sugar, 1983	Newborn, male	Imaging	8F, FT	Bladder	Dilatation, manipulation
Klein, 1986	4 years, female	CIC	10F, red rubber	Bladder	Dilatation, manipulation
Foster, 1992	6 months, male	Specimen	8F, FT	Bladder	Cystoscopy through patent urachus
Foster, 1992	2 years, male	Imaging	8F, FT	Bladder	Manipulation
Parker, 1993	15 months, female	Specimen	8F, FT	Bladder	Cystoscopy
Ball, 1993	8 years, male	CIC	8F, FT	Bladder	Cystoscopy
Konen, 1996	4 months, male	Imaging	8F, FT	Urethra	Bulbous urethrotomy
Carlson, 1997	7 months, male	Specimen	8F, FT	Bladder	Cystostomy
Gonzalves, 2000#	3 months, male	Imaging	NA, foley	Bladder	Manipulation
Steinbecker, 2001	11 years, male	CIC	12F, mentor	Stoma	Cystostomy
Arena, 2002	10 months, male	Specimen	8F, FT	Bladder	Manipulation
Dogra, 2003	12 years, male	CIC	6F, FT	Bladder	Cystoscopy
Turner, 2004	2 months, male	Specimen	5F, FT	Bladder	Manipulation
Lodha, 2005	<1 month, male	Specimen	5F, FT	Urethra	Manipulation with guidewire
Pappano, 2006	6 years, male	CIC	8F, FT	Bladder	Manipulation with guidewire
Ayyildiz, 2006	75 years, female	Urodynamics	12F, double lumen	Bladder	NA
Sithasanan, 2006	<1 month, male	Specimen	NA, FT	Bladder	Manipulation
Sambrook, 2007	<1 year, female	Specimen	4F, ureteral cath	Bladder	Manipulation with guidewire
Kilbane, 2009	8 months, female	Imaging	8F, FT	Bladder	Manipulation with guidewire
Bagheri, 2009#	6 months, female	Imaging	8F, Foley	Bladder	Manipulation with angiography catheter
Khullar, 2012	4 years, male	CIC	5F, FT	Bladder	Laparoscopy
Aybars, 2013	<1 month, female	Specimen	6F, FT	Bladder	Cystostomy*, cystoscopy
Jehangir, 2017	4 months, male	CIC	6F, FT	Urethra	Meatotomy
Terentiev, 2017	<1 month, female	Specimen	5F, FT	Bladder	Manipulation
Perera, 2017	5 months, male	Specimen	5F, FT	Bladder	Cystoscopy
Yousuke, 2017	1 month, male	Specimen	6F, FT	Urethra	Manipulation
Kervanciogu, 2018	<1 month, male	Imaging	6F, FT	Bladder	Manipulation
Erikci, 2018	3 years, female	Specimen	5F, FT	Bladder	Cystoscopy
This report	4 years, female	CIC	7F, FT	Bladder	Manipulation
This report	6 years, male	CIC	6F, FT	Urethra	Manipulation
This report	4 years, male	CIC	6F, FT	Bladder	Cystoscopy

Data from patients with knotting of catheters placed with indwelling intent from some of the quoted studies were purged. #Knotted Foley catheter, *Percutaneous cystostomy to permit cystoscopy. NA: Information not available, CIC: Clean intermittent catheterization, FT: Feeding tube

Previous reviews have often included patients, in whom catheters were placed with nonindwelling intent.[91631]

Almost all the affected patients were children from newborn to 12 years of age (33/34, 97%), except a 75-year-old female who had knotting of a urodynamics catheter [Table 1]. Boys were more commonly affected (22/34, 65%). The location of knotting was the bladder (28/34, 82%) urethra (5/34, 15%), or catheterizable conduit (1/34, 3%). Catheter size involved was 4F (1), 5F (6), 6F (7), 7F (1), 8F (14), 10F (1), 12F (2), and unknown (2). The most common type of catheter involved was an infant feeding tube (27/34, 79%). Other catheters involved were ureteric catheter (1), latex Foley (1), red rubber (2), mentor CIC catheter through catheterizable stoma (1), double-lumen urodynamics catheter in the 75-year-old female (1), and unknown (1).

Catheter knotting is logically related to five factors, namely length of insertion, diameter of catheter, physical characteristics of the material, catheterization technique, and anatomical patient factors. The latter two might be critical in urethral knotting. Failure to recognize the subtle pushback from urethral coiling or the presence of a capacious posterior urethra can allow urethral knotting to occur.

Limiting the length of insertion of catheter depending on the age and gender of the patient is important in avoiding this problem.[3] The urethra is 2.2 cm at birth, 2.5 cm at 5 years, and reaches 3.8 cm in adult females, while it is 5 cm at birth, 8 cm by 3 years, and reaches 17 cm in adult males.[32] It has been recommended that the maximum length of catheter insertion should be 5 cm and 6 cm in newborn females and males and 2.5 cm and 5 cm in premature females and males, respectively.[9] However, this would imply that the intravesical length of catheter in the male infant would be just 1 cm making it prone to slippage into the urethra. We recommend inserting the catheter not more than an additional 4 cm beyond the estimated urethral length in children under 5 years and 5 cm for older children. This is a reasonable compromise between reducing the risk of knotting while avoiding catheter slippage. The catheter should be taped to prevent inadvertent advancement if required such as during imaging studies.[12] These requirements are likely to be different in patients who are being catheterized with indwelling intent, where the design of the balloon catheter (distance between tip of catheter and base of balloon) may necessitate a longer insertion length and technique.[32]

Feeding tubes are commonly used to catheterize the bladder in young children since they are cheap and widely available in multiple small sizes.[3] Use of purpose-specific urethral catheters rather than generic feeding tubes or similar catheters with a visible clear mark on the catheter based on the age and gender may help to reduce the risk.

Narrower caliber catheters are more likely to coil, and one needs to balance between the potential trauma of larger catheters and the risk of knotting with smaller ones. Use of 8F catheters for children above the age of 1 year and 10F above the age of 9 years is suggested.[9] These calibers also allow for a rapid emptying of the bladder ensuring better compliance with CIC principles. When available, use of dedicated CIC catheters may be preferable to feeding tubes, but the authors are not aware of any study that has specifically studied this issue.

All patients (and parents of small children) should be counseled regarding the inadvisability of using force and the importance of recognizing the subtle pushback from catheters that might be coiling in the urethra. In all such situations, the need to withdraw the tube, relubricate the urethra, and reinsertion must be discussed.

Catheter removal was accomplished by manipulation alone using gentle traction (12/34, 35%), manipulation with detangling using a guidewire (5/34, 15%), manipulation with dilatation (3/34, 9%), endourology techniques (7/34, 21%), by an incision in 5 (meatotomy 1, bulbar urethrotomy 1, cystostomy 2, and percutaneous suprapubic cystostomy with cystoscopy 1), and laparoscopy in one patient. Catheter manipulation under general anesthesia in the operating room with copious lubrication can succeed despite failure of a similar attempt in the outpatient room. The relaxation to both patient and surgeon afforded by the general anesthetic was a key to removal in two of our patients. Rarely, one may need to resort to endourology techniques or a surgical incision. The latter is more likely in male infants where the risk of long-term iatrogenic urethral stricture may outweigh any concerns regarding the morbidity of a small retrieval incision.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.