The length of the male urethra

Köhler, Tobias; Yadven, Mitchell; Manvar, Ankur; Liu, Nathan; Monga, Manoj

doi:10.1590/s1677-55382008000400007

Cited by 43 publications

(30 citation statements)

References 6 publications

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“…This catheter is shorter than existing intermittent catheters, but still long enough to traverse the normal male urethra. 2 We have shown that the SpeediCath Compact Male is non-inferior to a standard-length intermittent catheter at emptying the bladder in men. The maximal residual volumes seen in this study (62.33 ml for the test catheter and 43.89 ml for the reference catheter) did not exceed what was to be expected based on previous studies.…”

Section: Ru Volume After Catheterizationmentioning

confidence: 86%

“…1 The male urethra has an average length of 223 mm (range 150-290 mm), 2 but existing male intermittent catheters range in length from 340 to 500 mm. 3 A newly marketed intermittent catheter, the SpeediCath Compact Male (Coloplast A/S, Humblebaek, Denmark), is a 30-cm-long sterile, ready-to-use, hydrophilic-coated catheter constructed in two parts using the telescope antenna principle.…”

Section: Introductionmentioning

confidence: 99%

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Clinical evaluation of a newly developed catheter (SpeediCath Compact Male) in men with spinal cord injury: residual urine and user evaluation

et al. 2011

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Objective: To evaluate the performance of a new 30-cm-long, telescoping male intermittent catheter (SpeediCath Compact Male; Coloplast A/S, Humlebaek, Denmark) in urinary bladder emptying, safety and subject acceptance vs a standard-length male intermittent catheter (SpeediCath). Materials and methods: In a prospective, randomized, multicenter, crossover non-inferiority study, 37 male intermittent catheter users self-catheterized three times with the test catheter on one test day and three times with the standard-length male (reference) catheter on another test day. Residual urine (RU) volume in the bladder after catheterization was measured by ultrasound. Safety was assessed in the entire study period in terms of adverse events (AEs) and adverse device events (ADEs). Subjects evaluated their experience, sensation, disposal, bleeding and discomfort with the test and reference catheters and final catheter preference. Results: SpeediCath Compact Male did not differ from the reference catheter in terms of performance (bladder emptying). The upper confidence limit of the mean difference between absolute RU volumes for the test and reference catheter groups did not exceed a pre-established non-inferiority limit of 20 ml, thereby showing the test catheter's non-inferiority to the reference catheter (that is, no worse at bladder emptying). The only AE/ADE reported was one instance of mild urethral burning for 30 min after catheterization, which was judged possibly related to the test catheter but resolved quickly. Conclusions: The SpeediCath Compact Male catheter is as efficient as a conventional intermittent catheter (SpeediCath) at emptying the bladder with the additional benefit of being more discreet and easier to use.

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Section: Ru Volume After Catheterizationmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Clinical evaluation of a newly developed catheter (SpeediCath Compact Male) in men with spinal cord injury: residual urine and user evaluation

et al. 2011

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“…Fig. 3 shows urethral length (8,(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) and diameter (15,(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34), flow rate (35)(36)(37)(38)(39)(40)(41)(42), bladder capacity (25,(43)(44)(45)(46)(47)(48)(49), and bladder pressure (1,35,39,40,43,46,50) for over 100 individuals across 13 species.…”

Section: Resultsmentioning

confidence: 99%

Duration of urination does not change with body size

Yang¹,

Pham²,

Choo³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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Many urological studies rely on models of animals, such as rats and pigs, but their relation to the human urinary system is poorly understood. Here, we elucidate the hydrodynamics of urination across five orders of magnitude in body mass. Using high-speed videography and flow-rate measurement obtained at Zoo Atlanta, we discover that all mammals above 3 kg in weight empty their bladders over nearly constant duration of 21 ± 13 s. This feat is possible, because larger animals have longer urethras and thus, higher gravitational force and higher flow speed. Smaller mammals are challenged during urination by high viscous and capillary forces that limit their urine to single drops. Our findings reveal that the urethra is a flow-enhancing device, enabling the urinary system to be scaled up by a factor of 3,600 in volume without compromising its function. This study may help to diagnose urinary problems in animals as well as inspire the design of scalable hydrodynamic systems based on those in nature.urology | allometry | scaling | Bernoulli's principle M edical and veterinary urology often relies on simple, noninvasive methods to characterize the health of the urinary system (1, 2). One of the most easily measured characteristics of the urinary system is its flow rate (3), changes in which may be used to diagnose urinary problems. The expanding prostates of aging males may constrict the urethra, decreasing urine flow rate (4). Obesity may increase abdominal pressure, causing incontinence (5). Studies of these ailments and others often involve animal subjects of a range of sizes (6). A study of urination in zero gravity involved a rat suspended on two legs for long periods of time (7), whereas other studies involve mice (8), dogs (1), and pigs (9). Despite the wide range of animals used in urological studies, the consequences of body size on urination remain poorly understood.The bladder serves a number of functions, as reviewed by Bentley (10). In desert animals, the bladder stores water to be retrieved at a time of need. In mammals, the bladder acts as a waterproof reservoir to be emptied at a time of convenience. This control of urine enables animals to keep their homes sanitary and themselves inconspicuous to predators. Stored urine may even be used in defense, which one knows from handling rodents and pets.Several misconceptions in urology have important repercussions in the interpretation of healthy bladder function. For instance, several investigators state that urinary flow is driven entirely by bladder pressure. Consequently, their modeling of the bladder neglects gravitational forces (11-13). Others, such as Martin and Hillman (14), contend that urinary flow is driven by a combination of both gravity and bladder pressure. In this study, we elucidate the hydrodynamics of urination across animal size, showing the effects of gravity increase with increasing body size. ResultsIn Vivo Experiments. We filmed the urination of 16 animals and obtained 28 videos of urination from YouTube, listed in SI Appendix. Movies ...

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“…A recent study showed an average male urethral length of B22 cm. 2 In contrast, the average female urethral length is B4 cm. 3 The urethral length differences have led to the development of novel shorter female intermittent catheters with greater comfort, ease of use and concealment.…”

Section: Introductionmentioning

confidence: 99%

Catheter length preference in wheelchair-using men who perform routine clean intermittent catheterization

et al. 2013

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Study design: Prospective, unblinded, multicenter, randomized, controlled, cross-over study assessing user preference and ease of use characteristics of two gel intermittent catheters in 81 self-catheterizing wheelchair-using men. Objectives: To evaluate the male user's preference between a 30-cm and a 40-cm intermittent catheter (Apogee Intermittent Catheter, Hollister Incorporated, Libertyville, IL, USA) regarding the ease of insertion and removal, ability to control the catheter during insertion, bladder emptying confidence and ease of draining urine into a receptacle or connecting to a urine bag. Setting: Multiple institutions in the United States. Methods: Subjects were randomized to order of catheter use, using both 10 test catheters (30-cm) and 10 control catheters (40 cm). All catheters were 12 or 14 French and identical in design and composition, except length. Safety was assessed during the entire study period regarding adverse events (AE) and adverse device events (ADE). Subjects evaluated their ease of use characteristics after each catheter use and final catheter preference. Results: Subjects preferred the Apogee 40-cm intermittent catheter (91.4%) over the 30-cm length (8.6%). The preference was due to subject confidence of complete bladder emptying (70%), more satisfactory length (74%) and easier to drain into a receptacle (58%) with a portable urinal being the most utilized (37%), followed by toilet (35%). The only AE/ADE reported was minor urethral bleeding in one subject and minor pain in another subject, both with the 30-cm catheter. None were reported with the 40-cm catheter. Conclusions: The Apogee 40-cm catheter was the preferred intermittent catheter due to subject confidence in bladder emptying, ease of catheter manipulation and the ease of draining urine into a receptacle.

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The length of the male urethra

Cited by 43 publications

References 6 publications

Clinical evaluation of a newly developed catheter (SpeediCath Compact Male) in men with spinal cord injury: residual urine and user evaluation

Clinical evaluation of a newly developed catheter (SpeediCath Compact Male) in men with spinal cord injury: residual urine and user evaluation

Duration of urination does not change with body size

Catheter length preference in wheelchair-using men who perform routine clean intermittent catheterization

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