Science of PE Posts and Threads. Link Here!

Here the other one:

"Revision of penile prosthesis surgery after use of penile traction therapy to increase erect penile length: case report and review of the literature.

Moskovic DJ, Pastuszak AW, Lipshultz LI, Khera M.

Scott Department of Urology, Baylor College of Medicine, Houston, TX, USA Columbia Business School, New York, NY, USA.

Abstract

Introduction.  Erectile dysfunction, a common consequence of radical prostatectomy (RP), can be managed with placement of a penile prosthesis. Patient satisfaction and functional outcomes have been related to penile length after prosthesis placement.

Aim.  We report a case demonstrating the impact of daily penile traction therapy in a patient with a previously placed penile prosthesis with the goal of enabling revision with a longer device.

Methods.  A post-RP patient who underwent inflatable penile prosthesis placement 6 years ago complained of inability to maintain partner penetration with his device. The patient underwent vacuum erection device therapy twice daily for 10 minutes per session for approximately 1 year as well as 8 hours of penile traction therapy daily for 8 months. A revision implant surgery was subsequently attempted. Main Outcome Measure.  Patient reported functional outcome.

Results.  Stretched penile length increased 2.3 cm after 6 months of traction therapy. A revision surgery enabled the placement of a prosthesis that was 20% longer in length (15 cm to 18 cm), and erect penile length increased by 4.4 cm. The patient reported that the new prosthesis enabled satisfactory maintenance of partner penetration.

Conclusions.  This case suggests that the use of a penile traction device increases penile corporal lengthand thus the length of a penile prosthesis that can be implanted in a patient with an unsatisfactory prosthesis already in place. Importantly, this patient experienced a substantial improvement in erect penile length after surgery. It is unknown whether these results are generalizable, either to all patients with a previously placed prosthesis or pre-prosthesis patients, representing an opportunity for further investigation.

Revision of penile prosthesis surgery after use of penile traction therapy to increase erect penile length: case report and review of the literature - PubMed

The role of vacuum pump therapy to mechanically straighten the penis in Peyronie’s disease.

Abstract
OBJECTIVE: to assess the efficacy of vacuum therapy in mechanically straightening the penile curvature of Peyronie’s disease (PD).

PATIENTS AND METHODS: Modelling of the tunica albuginea has been shown to be possible during penile implant surgery and this principle has been applied as an alternative conservative therapy. In all, 31 patients with PD (mean duration 9.9 months; mean age 51 years, range 24-71) completed the study. Over a 12-week period, the patients used a vacuum device (Osbon ErecAid, MediPlus, High Wycombe, UK) for 10 min twice daily. The assessment at study entry and at completion after 12 weeks included the International Index of Erectile Function questionnaire, a perceived pain intensity score, stretched penile length measurement and the angle of penile deformity after an intracavernous injection with prostaglandin E1.

RESULTS: there was a clinically and statistically significant improvement in penile length, angle of curvature and pain after 12 weeks of using the vacuum pump. Of the 31 patients, 21 had a reduction in the angle of curvature by 5-25 degrees, three had worsening of the curvature and there was no change in the remaining seven. The curvature was corrected surgically in 15 patients while the remaining 16 (51%) were satisfied with the outcome.

CONCLUSION: vacuum therapy can improve or stabilize the curvature of PD, is safe to use in all stages of the disease, and might reduce the number of patients going on to surgery.

The role of vacuum pump therapy to mechanically straighten the penis in Peyronie’s disease - PubMed

From Wikipedia:
A 31-patient study conducted by the Department of Urology at St Peter’s Hospitals and the Institute of Urology in London investigating the usefulness of pumps to correct the penile curvature associated with Peyronie’s disease found that “There was a clinically and statistically significant improvement in penile length, angle of curvature and pain after 12 weeks of using the vacuum pump”. In this study, subjects with Peyronie’s undertook two ten minute pumping sessions per day for twelve weeks. The additional penis length was an unexpected side effect and not an intended aim of the study, but large enough to be statistically significant.

vedstudy.pdf

Constrictive Penile Band Injury
Color Doppler Sonographic Assessment

Xavier Bargalló, MD,
Laura Buñesch, MD,
Carmen de Juan, MD,
Ramón Vilana, PhD and
Concepció Brú, PhD

trangulation of the penis is a rare injury, usually seen as a consequence of the placement of penile rings or bands, which are used to increase potency and to prolong erection.

Complications related to the use of penile rings or bands have been little reported. We report a case that describes the color Doppler sonographic findings in penile strangulation. The value of color Doppler sonography (CDS) in the clinical management of this injury is worth noting.

Case Report

A 36-year-old man was admitted to our hospital with a 3-day history of painful swelling of the penis related to a penile band, which had accidentally remained placed on his penis for 6 hours.

On physical examination, large swelling of the penis was evident. The dorsal artery pulse could not be palpated, although penile coloration was preserved. Color Doppler sonography was performed with a multifrequency linear array transducer (6–12 MHz, PowerVision 6000; Toshiba Medical Systems, Tokyo, Japan) to evaluate penile vascularization. Gray scale examination showed slight heterogeneity of the corpora cavernosa and spongiosum and poor definition of their margins. Moreover, a thick layer of echogenic tissue surrounding the Buck fascia was evident. In fact, the largest diameter of the penis was 7.3 cm, whereas the corpora cavernosa and spongiosum (considered together) measured 2.6 cm in diameter.

A color Doppler study revealed enhancement of normal vascularization (Fig. 1⇓) consisting of a circlet of arterial and venous vessels (due to enlargement of circumflex vessels). The dorsal artery was patent, maintaining its usual location (Fig. 2⇓). The superficial dorsal vein was laterally and dorsally displaced, being enlarged and patent (Fig. 3⇓). Intracavernosal arteries were also patent (Fig. 4⇓). Thus, the color Doppler study showed preserved vascularization, allowing us to adopt conservative treatment of the patient by following the wait-and-see rule. His penis recovered its normal size in 2 weeks without consequences.

The use of penile constrictive devices is a very dangerous practice that may produce a wide range of injuries from penile swelling to urethral lesions with fistulization and even gangrene.1 The fact that these devices produce ischemia has been shown by Broderick et al,2 who studied the value of CDS in the assessment of the hemodynamics of vacuum-induced erections. They concluded that because of the risk of ischemia, the constriction bands should not be worn for more than 30 minutes.2

………….
The clinical evaluation of penile strangulation includes assessment of temperature, color, sensation, the ability to void, and pulsation distal to the strangulation. The sonographic assessment should include careful evaluation of the corpora cavernosa and spongiosum, taking into consideration that the latter and the urethra are more susceptible to injury, because they are covered by a thin layer of fibrous tissue.1 Rupture of the cavernous bodies is very often associated with rupture of the urethra. Sonography should also exclude rupture of the tunica albuginea.

The color Doppler study provides information about vascular patency, and both arterial and venous vessels must be interrogated to rule out several important complications such as thrombosis or rupture of the cavernosal arteries and thrombosis of the dorsal penile vessels. Arterial supply to the penis is provided mainly through the dorsal arteries running close to the deep dorsal vein. Venous drainage of the penis is multiple. The superficial dorsal vein runs in the subcutaneous tissue, draining the prepuce and the skin of the penis, and joins the saphenous vein. The deep dorsal vein lies beneath the Buck fascia and receives the blood from the glans penis.3

…………….
Several cases of penile strangulation have been described in the literature,1,3–,5 although they have mainly focused on clinical management and surgical treatment. We have not found reports on the color Doppler sonographic assessment of such an injury, despite the fact that the value of CDS in the vascular assessment of the penis is widely known.6,7

In our case, CDS was able to show the patency of the vascular system of the penis. Both arterial and venous vessels were enlarged. This finding was thought to be related to reactive hyperemia (due to anoxic injury). The duration of this phenomenon is proportional to the duration of the occlusion.

The enlargement of the penile transverse diameter was caused by subcutaneous edema without changes in the size of the corpora. This fact could be related to venous stasis and also to impairment of lymphatic drainage.7 Supporting the latter hypothesis is a reported case of long-term use of a penis-enlarging ring in which pathologic examination revealed enlargement of the lymphatic vessels.8 Moreover, the residual edema may be considerable and in some cases may require removal of the skin and subsequent grafting.3
………
http://www.jult rasoundmed.org/ … t/21/2/215.full

Treating Erectile Dysfunction with a Vacuum Tumescence Device:
A Retrospective Analysis of Acceptance and Satisfaction

S. Baltaci, M.D. Urologist, K. Aydos, M.D. Urologist, A. Koser, M.D. Urologist, K. Anafarta. M.D. Professor of Urology Correspondence: Dr. S. Baltaci. Kavacik Subayevleri

British Journal of Urology (1995), 76.757-760

Medical study stating that 88% of participants who used a Vacuum Therapy Device, reported a erection rigid enough for intercourse and an improvement in their natural, spontaneous erections.

Introduction
Objectives: To evaluate the quality of erections, ability to perform sexual intercourse, incidence of complications and satisfaction of patients using an external vacuum erection device in the treatment of erectile failure. Patients and methods. Of the 61 impotent men who participated in this clinical trial, 49 used the device and were surveyed. The mean follow-up period was 12.8 months. A subjective rating scale from 1 to 10 was used to assess to patients satisfaction with the device where 1 indicated dissatisfied and 10 indicated very satisfied. Results. The ease of using the device, satisfaction with quality of erections and ability to perform intercourse were given scores>5 by 88.84 and 82% of the patients, respectively. Sixteen (33%) of the men withdrew for the trial, primarily because they were unable to achieve and maintain a full erection, suffered conflicts in their relationship, or for reasons not related to the device.

Overall, the effectiveness rate was 67%. Of 32patients with arteriogenic impotence, 28 (88%) had satisfactory results and had an improvement in their capability for spontaneous erections with the device. The most frequent adverse effects were blocked ejaculation, bruising or the development of ecchymosus-discomfort during pumping and discomfort from using the constriction bands.

Conclusion. These results suggest that the vacuum device is an effective and safe treatment for impotence of various aetiologies, especially for those patients with arteriogenic impotence.

Despite considerable therapeutic advances in the management of impotence, e.g. the advent of effective penile protheses, self-injection of vasoactive drugs and effective vascular surgical procedures, one reversible non-invasive form of treatment, i.e. the vacuum device appears to be ideal. Vacuum constriction devices provide a mechanical, non-surgical and reversible means of inducing and maintaining an erection and appear to be an attractive alternative to either no treatment or other treatment modalities. Several studies have demonstrated that external vacuum devices can produce erections sufficient for intercourse in 89-100% of men with erection problems of various aetiologies.

The use of these devices for the treatment of impotence is gradually gaining acceptance among patients and urologists. In the last decade, vacuum devices have become available in Turkey and are being increasingly used in the therapy for those unwilling to enter self injection programs or to undergo surgical procedures. We initiated a study using an external vacuum erection device to determine whether it is effective in restoring erectile function and coital capacity.

Patients and methods
A total of 61 patients with erectile difficulty participated in a clinical trial of an external vacuum device. Of the 61 men who began the clinical trial, 12 were lost to follow-up and this report concerns the 49 men who used the device and were surveyed. The evaluation of patients included a thorough medical and sexual history and physical examination, nocturnal penile tumescence testing (NPT), endocrine studies, an intracavernosal papaverine test, and color Doppler flow ultrasonography (CDFU) in addition to cavernosometry, cavernosography, sacral latency-time testing psychiatric evaluation when needed. For the papaverine test 60 mg of papaverine hydrochloride was injected intracavernosally.

If a good erection was produced within 10 min. and maintained for 30 min. the patient was considered to have to cavernosal vascular pathology. The CDFU examination was performed after and injection with 60 mg of papaverine-HCI, when arterial and venous functions were assessed as described previously. A peak systolic velocity in the cavernosal arteries of <25cm/s and a diameter increase of these arteries of <75% were considered as indicating arterial dysfunction. However, enddiastolic velocities of cavernosal arteries of <5 cm/s indicated venous pathology.

The cavernosometric study was performed in the radiology suite. Measurements were made 10 min. after an injection with 60mg papaverine. A maintenance flow rate of>30mL/min to maintain intracorporeal pressure at>90mmHg and a drop in intracorporeal pressure from 150 mmHg to <100mmhg at 30.s and to <60mmhg at 5 min. after stopping infusion was considered as indication corporeal veno-occlusive dysfunction. The parameters used to indicate arterial dilation amd a peal velocity of <25 cm/s by CDFU.

The age of the patients ranged from 23 to 67 years, with mean age of 48 years. The mean duration of impotence was 2.8 years (range 6 months-10 years.) Of the 49 subjects, 40 were diagnosed as having organic erectile difficulties (arteriogenic in 32, venogenic in six and neurogenic in two), while seven had erectile failure of mixed aetiology and two had psychogenic erectile problems. After the various options for the treatment of impotence were discussed, these patients elected to use the vacuum erection device. The men were instructed on the use of the device by verbal explanation and the individual demonstration sessions were also performed. The men were instructed to begin their use with the largest constriction band, but to use a smaller band only if his erection could not be maintained. The men returned to the clinic for follow-up evaluations after 2 and 4 weeks of use. A physical examination was performed to detect symptoms and signs of complications and they were interviewed regarding complications, side effects and their satisfaction with the device. After the first two visits further information was obtained by direct questioning of patients during follow-up visits or in a telephone survey, or by letters with standardized questionnaires.

The ease of use, quality of the erection achieved and the ability to perform sexual intercourse were used to assess satisfaction, employing a subjective rating scale of 1 to 10 where 1 indicated dissatisfied and 10 indicated very satisfied.

Results
Follow-up of the 49 patients ranged from 2 to 32 months (mean 12.8) during which they received no additional therapy. Overall, the rate of effectiveness was 67%. Of the 49 men, four (8%) had an improvement in spontaneous erections after a mean of 2 months of use and had periodic sexual activity, consisting primarily of manual stimulation with using the device, and they had discontinued its use. These four patients had borderline arteriogenic impotence before treatment. Of the remaining 45 patients, 29 (64%) were still using the device successfully a mean 6.1 times per month and experienced an improvement in their capacity for spontaneous erection.

These 29 men were also asked to rate the quality of the device and 17 (59%) of them experienced a significant improvement in the quality and frequency of erections. The patients’ degree of satisfaction with the device is presented in Table 2. The case of using he device, satisfaction with the erection quality and ability to perform intercourse were given scores of>5 by 88.84 and 82% of the men, respectively. The frequency of sexual desire or masturbation was increased in five patients, whereas in two it was decreased.

Of the 49 men who entered the program 16 (33%) withdrew between 1 and 3 months after the start. Two men left for reasons unrelated to the device, one because of poor health (gastric cancer) and the other with marital problems. Reasons for withdrawal are presented in Table 3. Throughout the trial, 12 patients reported discomfort during pumping and 22 reported discomfort from the use of the constriction bands. However, with time these effects disappeared in the majority and only one patient stopped using the device. Thirteen men (27%) with normal ejaculatory ability reported blocked ejaculation with the constriction bands in place. Bruising or development of echymosis occurred on 19 patients 939%) during the trial. One man had a haematoma and stopped using the device.

Two other men experienced dizziness during pumping. The majority of these complications occurred during the first month of use. Follow-up physical examinations revealed no penile abnormalities such as fibrosis, intracorporeal induration or skin changes.

Discussion
Although intracavernosal injections of vasoactive drugs and improved penile prosthesis have been used successfully by many patients, they are not without adverse affects. However, a reversible non-invasive form of treatment of impotence appears to be ideal and this led to renewed interest in external vacuum devices. Indeed, the concept of vacuum-included erections is at least 75 years old.

Erections of sufficient quality for penetration and intercourse induced by external vacuum devices were reported in 68-100 % of men with erection problems of various aetiologies. The rate of effectiveness in the present study (67%) although lower than many other reports, was similar to that found in some previous studies. The men tended to increase their satisfaction score by improving the rate of pumping and by proper selection of ring size for the vacuum cylinder. In previous reports, no relationship was found between the quality of spontaneous erectile capacity of subjects in the organic, mixed and psychogenic erectile failure groups. However, in the present study of 32 patients with arteriogenic impotence, four had spontaneous erections after a mean of 2 months and subsequently did not need the vacuum device. Additionally, 24 patients with arteriogenic impotence experienced improvements in their capacity for spontaneous erections.

Overall, 28 of 32 (88%) patients with arteriogenic impotence had satisfactory results and improvements in the capacity for spontaneous erections with the external vacuum device. Although unproven, repeated application of the vacuum device may lead to improvement in the intracavernosal sinusoidal distension which possibly explains the satisfactory result in those with aeteriogenic impotence. Bosshardt et al (17) recently reported improvements in the duration and extend to nocturnal penile tumescence and rigidity after patients used the vacuum device for 2 weeks at home. Patients who reported having spontaneous morning erections showed significant improvements in total erection time, erection phase and plateau-phase duration, effective rigidity and tumescence increase. Bosshardt et al concluded that the increase in penile volume during the application of the device was caused not only by arterial inflow, but also by venous backflow.

In the present study, discomfort during the application of pressure was experienced in 12 patients (25%), but only one was severe enough to discontinue use. Discomfort from the use of the constriction bands was however reported in 22 patients (45%) but these problems disappeared with time. The incidence of both problems was similar to that in other studies. Skin bruising and ecchymosis occurred in 19 (395) patients who had experienced haematoma stopped using the device. In other studies, ecchymosis and skin bruising occurred in 21-37 % of the patients. Absence of ejaculatory fluid occurred in 27% of patients in the present study in previous studies. The reported incidence of blocked ejaculation was between 12 and 39%. Although most users did not describe blocked ejaculation to be a problem, this finding also indicates that vacuum devices need not me discarded as a treatment alternative in couples who are trying to conceive.

The most common reasons for discontinuation of the device in the present study were poor quality of the erections achieved and conflicts in personal relationships. Several investigators have also reported the difficulties that patients and partners encounter with these devices. These factors should be considered in planning programs for the education of patients and a short course of therapy for couples is often needed for them to become completely familiar with the device and adapt to its use. In summary, the external vacuum device is an effective and attractive treatment alternative for impotence of various aetiologies, especially for arteriogenic impotence. Limitations of the therapy include inability to achieve and maintain a full erection, conflicts in relationships and change in ejaculatory pattern

http://rejoynme dical.com/artic … ysfunction.html

Traction Therapy for Men with Shortened Penis Prior to Penile Prosthesis Implantation: A Pilot Study

Laurence A. Levine MD,
James Rybak MD

Article first published online: 14 APR 2011

ABSTRACT

Introduction.  Loss of penile length after penile prosthesis implantation is one of the most common complaints. There is no recognized reliable technique to gain length once the device is placed.

Aims.  This noncontrolled pilot study was designed to evaluate the efficacy and safety of external penile traction therapy in men with a shortened penis used before inflatable prosthesis implantation.

Methods.  Ten men with drug refractory erectile dysfunction and a complaint of a shorter penis as a result of radical prostatectomy in four, prior prosthesis explantation in four, and Peyronie’s disease in two were entered into this trial. External penile traction was applied for 2–4 hours daily for 2–4 months prior to prosthesis surgery.

Main Outcome Measures.  Baseline stretched penile length (SPL) was compared with post-traction SPL and postimplant inflated erect length. A non-validated questionnaire assessed patient satisfaction.

Results.  All men completed the protocol. Daily average device use was 2–4 hours and for up to 4 months. No man had measured or perceived length loss after inflatable penile prosthesis placement. Seventy percent had measured erect length gain compared with baseline pre-traction SPL up to 1.5 cm. There were no adverse events.

Conclusion.  External traction therapy appears to result in a preservation of penile length, as no man had measured or perceived length loss following prosthesis placement, but in fact, a small length gain was noted in 70% of the subjects with no adverse events. The protocol is tedious and requires compliance to be effective. External traction therapy prior to inflatable penile prosthesis placement appears to preserve and possibly result in increased post-prosthesis implant erect length. Levine LA and Rybak J. Traction therapy for men with shortened penis prior to penile prosthesis implantation: A pilot study. J Sex Med 2011;8:2112–2117.

http://onlineli brary.wiley.com … 2285.x/abstract

Original Article
Eur J Pediatr Surg 2009; 19(4): 236-240
DOI: 10.1055/s-0029-1215600

Effect of Penile Tourniquet on Growth Factors in Rat Penile Tissue

M. Kaya1, T. Soyer1, S. Ayva2, M. Çakmak1
1 Department of Pediatric Surgery, Faculty of Medicine, Kirikkale University
2 Department of Pathology, Medical Faculty, Kirikkale University
Abstract

Aim: This study aimed to evaluate the effect of penile tourniquet application on growth factors in rat penile tissues.

Materials and Methods: Forty Wistar male rats were included in the study. Rats were divided into 4 groups. After anesthetization, perimeatal penile skin and the corpus cavernosum were sampled in the control group (CG). A Mathieu-like flap was designed without a penile tourniquet (PT) to serve as a sham group (SG). In the PT groups, a Mathieu-like flap was created and a 5 mm diameter rubber circular band was applied at the base of the penis. The PT was applied for 10 min in the PT-10 group and for 30 min in the PT-30 group. Penile tissue was sampled 24 h after PT application in the SG and PT groups. Tissues obtained were examined in three sections: the subepithelial vascular plexus (SVP), the corpus cavernosum (CC) and the smooth muscle-like mesenchymal cells in the corpus cavernosum (MC). Acute inflammation was evaluated with hematoxylin-eosin staining. The effect of PT on vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR) and transforming growth factor β receptor (TGF β-R) levels was evaluated.

Results: Higher grades of acute inflammation were encountered in the PT-10 and PT-30 groups compared to the CG and SG (p<0.005). However, mean grades of acute inflammation did not show a statistical difference between the PT-10 and PT-30 groups (p>0.05). When the levels of growth factors were compared between the CG and PT-10 group, the PT-10 group showed increased levels of VEGF and TGF β-R. In the PT-30 group, both VEGF and VEGFR levels were found to be decreased. When acute inflammation grades of tissues were correlated with VEGF and TGF β-R, higher acute inflammation grades correlated with decreased VEGF and increased TGF β-R levels (Spearman's correlation, p<0.005). Although alterations in VEGF and TGF β-R levels were detected in the SVP and CC of penile tissues, altered VEGFR levels were only detected in the MC sections.

Conclusion: PT caused higher grades of acute inflammation which correlated with decreased VEGF levels and increased TGF β-R levels. Decreased VEGF levels after PT may alter the angiogenesis phase of wound healing and cause poor angiogenesis in penile skin flaps. Increased levels of TGF β-R can be considered as an acute inflammatory response to PT. These results confirmed that prolonged PT application may result in altered growth factors in penile tissue and may reduce the success rate of repair.

Comment: the results seems also confirm that mild damage and short term application of a torniquette increase levels of VEGF.

There is a lot of current anicdotal evidence supporting these studies on franktalk.org.

Thanks. This thread is intended to be a collection of scientific studies, so no other posts should be allowed here - that’s the Penismith’ willing. But I would be grateful if you could link some of those posts somewhere else - for example in the chemical PE thread, or anywhere it seems more pertinent to you.

"J Urol. 1992 Nov;148(5):1432-4.
Penile extensibility: to what is it related?
Moreira de Goes P, Wespes E, Schulman C.
Source

Department of Urology, Erasme Hospital, University Clinics of Brussels, Belgium.
Abstract

Penile extensibility is the difference between the length of the flaccid penis and the penis submitted to a maximal constant traction. This measurement has been proposed for use as a new potential diagnostic method to assess intracavernous fibrosis. To determine the value of this method we measured penile extensibility before and after removing the skin and cavernous tissue in 17 cadavers and 4 patients undergoing penile implantation. In all cases a cavernous tissue biopsy was performed and the percentages of the different structures were objectively quantified by computer analysis. The extensibility decreased with patient age but it was not influenced by removal of the skin and/or cavernous tissue. No correlation was observed between decreased extensibility and the increase in fibrotic elements in the penile tissue.

Penile extensibility seems to reflect the elasticity of the tunica albuginea, which is the limiting factor and cannot be an expression of fibrosis of the corpora cavernosa.

Penile extensibility: to what is it related? - PubMed

"Penile prostheses"
Carlo Bettocchi
Department of Emergency and Organ Transplantation – Urology, Andrology and Kidney Transplantation Unit, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy
Fabrizio Palumbo, Marco Spilotros, Silvano Palazzo, Gabriele A. Saracino, Pasquale Martino, Michele Battaglia, Francesco P. Selvaggi, and Pasquale Ditonno

Penile prostheses

"The Apollo™ prosthesis (Giant Medical Corporation, Cremona, Italy) is a device designed to be filled periodically with saline solution in order to obtain tissue expansion. It represents a temporary device eligible for use when it is necessary to increase the length of the corpora before implantation of the definitive prosthesis "

This study demonstrates that the tunica can grow in response to internal pressure.

The "penile extensibility" study states that if you pull on your dick it will stretch until the tunica reaches its maximum.

It says nothing about how the penis grows.

The term "limiting factor" is used in a different context.

The tunica is the limiting factor in terms of how far your dick can stretch. The tunica is probably not the limiting factor in terms of growth.

Could the amount of internal pressure used in this study be mimicked by accessible "items" ?

This is not the place to start discussions. Here there should be only studies, without arguing or exchange of opinions. Respect the OP willing, please.

J Androl. 2004 May-Jun;25(3):426-31.
Anatomy of the human penis: the relationship of the architecture between skeletal and smooth muscles.
Hsu GL, Hsieh CH, Wen HS, Hsu WL, Wu CH, Fong TH, Chen SC, Tseng GF.

Abstract

To investigate the anatomy of the ischiocavernosus muscle, bulbospongiosus muscle, and tunica albuginea and to determine their relationships to smooth muscle, which is a key element of penile sinusoids, we performed cadaveric dissection and histologic examinations of 35 adult human male cadavers. The tunica of the corpora cavernosa is a bilayered structure that can be divided into an inner circular layer and an outer longitudinal layer. The outer longitudinal layer is an incomplete coat that is absent between the 5-o’clock and 7-o’clock positions where 2 triangular ligamentous structures form.

These structures, termed the ventral thickening, are a continuation of the anterior fibers of the left and right bulbospongiosus muscles. On the dorsal aspect, between the 1-o’clock and 11-o’clock positions, is a region called the dorsal thickening, a radiating aspect of the bilateral ischiocavernosus muscles. In the corpora cavernosa, skeletal muscle contains and supports smooth muscle, which is an essential element in the sinusoids. This relationship plays an important part in the blood vessels’ ability to supply the blood to meet the requirements for erection, whereas in the corpus spongiosum, skeletal muscle partially entraps the smooth muscle to allow ejaculation when erect. In the glans penis, however, the distal ligament, a continuation of the outer longitudinal layer of the tunica, is arranged centrally and acts as a trunk of the glans penis. Without this strong ligament, the glans would be too weak to bear the buckling pressure generated during coitus.

A significant difference exists in the thickness of the dorsal thickening, the ventral thickening, and the distal ligament between the potent and impotent groups (P < or =.01). Together, the anatomic relationships between skeletal muscle and smooth muscle within the human penis explain many physiologic phenomena, such as erection, ejaculation, the intracavernous pressure surge during ejaculation, and the pull-back force against the glans penis during anal constriction. This improvement in the modeling of the anatomic-physiologic relationship between these structures has clinical implications for penile surgeries.

Anatomy of the human penis: the relationship of the architecture between skeletal and smooth muscles - PubMed

J Sex Med. 2012 Jan;9(1):288-95. doi: 10.1111/j.1743-6109.2011.02519.x. Epub 2011 Oct 24.
Combination of penile traction, intralesional verapamil, and oral therapies for Peyronie's disease.
Abern MR, Larsen S, Levine LA.
Source

Department of Urology, Rush University Medical Center, Chicago, IL 60612, USA.
Abstract
INTRODUCTION:

There is no current consensus as to the most effective nonsurgical therapy for Peyronie’s disease (PD).
AIM:

This study aims to assess the benefit of penile traction therapy (PTT) when added to intralesional verapamil injections (IVIs) combined with oral L-arginine 1 g b.i.d. and pentoxifylline 400 mg t.i.d. in men with PD.
METHODS:

Seventy-four men with PD completed 12 IVIs. Patients electing to add PTT were advised to wear the device for 2-8 hours daily and no longer than 2 hours per session. Subjective responses were measured using patient questionnaires. Stretched penile length (SPL) and erect penile curvature (EPC) using penile duplex ultrasound were measured. Response to therapy was defined as at least a 10-degree reduction in EPC.
MAIN OUTCOME MEASURES:

Change in SPL (cm) and change in EPC (degrees).
RESULTS:

Thirty-five patients in group I vs. 39 patients in the PTT group II completed the protocol. Fifty-four percent of men in group II responded to therapy vs. 46% in group I (P = 0.75). Responders in group II had a mean EPC improvement of 26.9 degrees vs. 20.9 degrees in group I (P = 0.22). Mean PTT use was 3.3 hours per day, and men with >3 hours per day use gained 0.6 cm in SPL vs. 0.07 cm using less than or equal to 3 hours per day (P = 0.09), while men in group I lost 0.74 cm of SPL on average. Multivariate analysis revealed that duration of PTT use significantly predicts length gain (0.38 cm gain for every additional hour per day of PTT use, P = 0.007).

CONCLUSIONS:

There was a trend toward measured curvature improvement and a significant gain in SPL in men using the combination therapy protocol. Length improvement is related to duration of use of the traction device.

Combination of penile traction, intralesional verapamil, and oral therapies for Peyronie’s disease - PubMed

Comment: so, we do have a pointer: extenders should be worn for at least 3 hours daily. This study only refers to people with PD though.

Edit: here the full aritcle
http://onlineli brary.wiley.com … 11.02519.x/full

the whole experiment lasted 24 weeks.

I don’t know if this was already posted here, but it shows that kegels help ED

Pelvic floor exercises for erectile dysfunction.
Dorey G, Speakman MJ, Feneley RC, Swinkels A, Dunn CD.
Source

The Somerset Nuffield Hospital, Taunton, UK. grace.dorey@virgin.net
Abstract
OBJECTIVE:

To examine the role of pelvic floor exercises as a way of restoring erectile function in men with erectile dysfunction.
PATIENTS AND METHODS:

In all, 55 men aged > 20 years who had experienced erectile dysfunction for > or = 6 months were recruited for a randomized controlled study with a cross-over arm. The men were treated with either pelvic floor muscle exercises (taught by a physiotherapist) with biofeedback and lifestyle changes (intervention group) or they were advised on lifestyle changes only (control group). Control patients who did not respond after 3 months were treated with the intervention. All men were given home exercises for a further 3 months. Outcomes were measured using the International Index of Erectile Function (IIEF), anal pressure measurements and independent (blinded) assessments.
RESULTS:

After 3 months, the erectile function of men in the intervention group was significantly better than in the control group (P < 0.001). Control patients who were given the intervention also significantly improved 3 months later (P < 0.001). After 6 months, blind assessment showed that 40% of men had regained normal erectile function, 35.5% improved but 24.5% failed to improve.
CONCLUSION:

This study suggests that pelvic floor exercises should be considered as a first-line approach for men seeking long-term resolution of their erectile dysfunction.