Abstract
Context: Hidden penis is anatomically defined by a lack of firm attachments of the skin and dartos fascia to the underlying Buck fascia.
Objective: To critically appraise the research evidence that could support the most effective surgical techniques for adult-acquired hidden penis in obese patients.
Methods: Studies investigating patients with a diagnosis of hidden penis were identified. Of these studies, only those with adult patients classified as overweight or obese (body mass index >25) were included in the review. Three reviewers examined the abstracts of the studies identified in the initial Medline search, and abstracts considered potentially relevant underwent full-text review. Studies that included patients with congenital, iatrogenic (eg, circumcision issues or aesthetic genital surgery), or traumatic causes of hidden penis were excluded. Studies that did not define the diagnostic criteria for hidden penis were excluded to minimize the risk of definition bias. The quality of evidence for each study was determined after considering the following sources of bias: method of allocation to study groups, data analysis, presence of baseline differences between groups, objectivity of outcome, and completeness of follow-up. Using these criteria, studies were then graded as high, moderate, or low in quality.
Results: Seven studies with a total of 119 patients met the inclusion criteria. All but 1 of the studies were nonrandomized. One study provided a clear presentation of results and appropriate statistical analysis. Six studies accounted for individual-based differences, and 1 study failed to account for baseline differences altogether. Four studies addressed follow-up. One study was of high quality, 2 were of moderate quality, and 4 were of low quality.
Conclusion: Building a clinical practice guideline for the surgical management of hidden penis has proven difficult because of a lack of high-quality, statistically significant data in the research synthesis. The authors elucidate the challenges and epitomize the collective wisdom of surgeons who have investigated this problem and emphasize the need for rigorous evaluative studies.
In 1919, Edward Loughborough Keyes, MD, described a condition in which the penis is concealed within the subcutaneous tissues of the perineum.
1 Recent attention has been given to adult-acquired hidden penis, a condition in which the penis is buried beneath the suprapubic subcutis. In adults, hidden penis is most often the result of obesity or penoscrotal lymphedema.
2,3 Although several classification systems exist, the terms
hidden, buried, concealed, trapped, and
inconspicuous are used interchangeably to describe this condition throughout the literature.
4 Regardless of the term used, authors describe obese patients who have visible and functional decreases in penile length due to excessive suprapubic weight.
5
Although morbid obesity plays an important role in the pathophysiology of hidden penis, it is not pathognomonic, suggesting a multifactoral origin. Specifically, an abnormal mobility of the dartos fascia and an inadequate attachment to the Buck fascia are implicated.
6 Two secondary complications arise that restrict penile mobility. Excess pubic fat effectively traps the penis because the corpora are fixed to the symphysis, and moisture in the closely opposed skin surfaces incites a chronic inflammatory dermatitis with scarring.
7 These complications are formidable challenges for the surgeon.
Determining the best surgical approach to hidden penis on the basis of the literature is hampered by a lack of consensus, the existence of multiple algorithms, and reports of variable success. Using an algorithmic approach, Pestana et al
8 reviewed release techniques, including scar and suspensory ligament release. On the basis of their findings, the authors recommended panniculectomy when necessary. Notably, Pestana et al
8 emphasized reconstructive techniques that used well-vascularized soft tissue. King et al
9 addressed hidden penis with a similar algorithm but advocated suprapubic lipectomy rather than panniculectomy. When necessary, this group restored soft tissue integrity with free-skin grafts. Tang et al
10 included techniques such as escutheonectomy and split-thickness grafts secured with fibrin glue.
Considering the growing prevalence of obesity in the United States,
11 a relative paucity of literature exists describing adult-acquired hidden penis. Our primary objective was to critically appraise the research evidence that could indicate which surgical practices are effective for adult patients with hidden penis. Our secondary objective was to identify the surgical techniques used in the management of this condition.
We assessed the limitations in study design and the risk of bias across all studies (
Table 1). The quality of evidence was downgraded according to explicit criteria for the seriousness of the risk of bias and limitations in study design. One of the 7 studies provided a clear presentation of results and appropriate statistical analysis. Six studies were nonrandomized. Two studies lacked statistical analysis, 6 studies lacked a clear presentation of results, and 1 study lacked both measures of quality. Six studies appropriately accounted for individual-based differences, but 1 study failed to account for baseline differences. Four studies addressed follow-up. Three of these studies provided postoperative follow-up of 80% of the original sample. One of the 4 studies reporting postoperative penile length revealed a statistically significant difference.
All studies reported the use of specialized dressing materials or tissue sealant products. Despite the well-documented influence of manufacturer funding in clinical trials, only 3 reports disclosed any manufacturer relationship or provided a uniform declaration of conflict of interest. Although not inherently improper, a conflict of interest increases the risk of bias in research.
A lack of randomization introduces a high risk of bias. Definition bias occurred in 2 of the studies, whereby misdiagnosis affected the accuracy of observations.
We determined that the quality of the body of the evidence, categorized into 4 levels, was low in 4 studies, moderate in 2 studies, and high in 1 study.
Among the 119 patients, 83 underwent penile release by cicatrixectomy or lysis of fascial adhesions. Eighty-five patients underwent suspensory ligament release, with 64 undergoing supplementary fundiform ligament release. Ninety-nine patients underwent suction lipectomy or panniculectomy. Additional techniques for penile release included z-plasty, abdominoplasty, escucheonectomy, and scrotoplasty.
Techniques for skin closure and coverage varied. In 65 patients, a local flap technique was used. In 5 of 10 patients receiving split-thickness skin grafts, fibrin glue was used to secure the closure. Primary skin closure was done in 8 patients and z-plasty in 5 patients. Closures were unspecified for 16 patients.
Management of hidden penis takes place in a care continuum that includes (1) accurate anatomic diagnosis and risk assessment; (2) preoperative preparation, including concerted efforts to improve local hygiene and to manage intertrigo and balantitis; (3) panniculectomy when indicated; and (4) restoration of soft-tissue integrity. This research synthesis attempted to scrutinize the reported experiences of urologists who take on these complex cases.
Owing to the dearth of available and relevant studies on hidden penis in adults, this investigation provides little more than a starting point and, at most, the basis for a well-designed randomized trial. Methodologic limitations exist in much of the evidence base for the management of adult-onset hidden penis. Imprecision, lack of clarity, bias, and insufficient attention to confounding variables seem to be common on the basis of our findings. When interpreting observational studies, urologic surgeons should be mindful that they may be relying on methodologically poor research. The quality of clinical decisions and confidence in their outcomes will never be better than the quality of information supporting those decisions.
From the current review emerged a concern for the failure to account for baseline differences. That is, the patient selection process and indications were unrefined. In studies lacking a satisfactory description of individual baseline differences, confounders cannot be properly adjusted for, nor can associations with technique and results be tested for statistical significance. In addition, analyzing complex observational data based on naive cohort distinctions can result in biased estimates of the effect of surgical interventions.
It is implausible to improve the quality of urologic care without measuring patient outcomes. Complications such as penile deformity, paradoxical penile shortening, abnormal scarring, granuloma formation, sexual dysfunction, and psychological sequelae are important outcome measures in both early- and late-interval follow-up. However, among the study set, outcome measures were poorly defined and, with 1 exception, no long-term assessment of outcome was performed. Five of the 7 studies merely conveyed an overall satisfaction among all of their postoperative patients. One study
16 alluded to rating outcomes using a scale published by pediatric urologists who reported, “Perfect cosmetic results were obtained and no serious complications developed.”
Imperfect as the literature is, however, the core processes of care entailed in the current treatment of patients with hidden penis can be epitomized.