A cost-effective modified split graft technique using bovine pericardium after plaque excision in Peyronie’s disease - An initial experience

Abstract

Aims:

The plaque excision and grating technique is indicated for correcting penile curvature in Peyronie’s disease. We assessed our experience of the modified split graft technique using bovine pericardium after plaque excision.

Materials and Methods:

Between March 2020 and September 2024, we operated on 12 patients by the excision of plaque and split grafting technique. Here, we discuss our experience customizing a bovine pericardium graft on a table according to the size of the defect and joining pieces of graft and tunica albuginea with a Polydioxanone (PDS) suture to cover the cavernosal defect.

Results:

Patients’ mean age and follow-up were 48 years and 30 months, respectively. The average size of the plaque and penile curvature was 4.6 cm (range 1.5–8 cm) and 45°, respectively. No residual penile curvature was observed in 83.5% of patients while (16.5%) had curvature of <20°. All patients experienced an improvement in stretched penile length with an average increase of 1.6 cm. Seventy-five percent of patients were able to perform sexual activity without assistance after 3 months. One patient, who had a sizeable cavernosal defect of 8 cm × 2 cm, experienced severe postoperative erectile dysfunction (ED) along with residual penile curvature of 15° and required semi-rigid penile prosthesis. Two patients having mild ED was managed by Tadalafil 10 mg. Another patient with residual chordee of <20° was managed on conservative therapy.

Conclusions:

In our limited experience, this modified split graft technique using bovine pericardium after plaque excision seems feasible, cost-effective, and safe. It has comparable outcomes to the standard methods reported in the literature and reduces graft material wastage. Further, long-term randomized trials are needed to validate its long-term efficacy and safety compared to conventional grafting approaches.

INTRODUCTION

Peyronie’s disease (PD) is a urological disease, characterized by fibrous plaques in the tunica albuginea layer of the penis.[1] The exact etiologies of PD are unknown.[2] The condition is characterized by pain in the penis on erection, especially in the acute phase, penile curvature, penile plaques, shortening of the penis, and difficulty in sexual activity due to bending (dorsal, ventral, and lateral) of the penis.[3,4] PD may accompanied by erectile dysfunction (ED). A decrease in penile length, penile curvature, and difficulty in sexual intercourse can cause significant mental trauma for the patient and negatively impact their quality of life.[5,6,7] According to previous studies, the prevalence rate of PD in the general population is approximately 3%–9%, increasing with age.[8,9,10,11] PD is a clinical diagnosis, although sometimes ultrasound with color Doppler of the penis or magnetic resonance imaging is required for confirmation. Several pharmacological treatments/traction and shock-wave therapies are available for PD. However, their success rates vary.[12] Therefore, in patients who have difficulty in sexual activity due to curvature of the penis, surgery remains the gold standard for treatment in stable disease and helps the patient to resume his normal penile anatomy and regular sexual activity.[13] According to the current treatment guidelines, in men with a severe disease having a curvature of the penis more significant than 60° and preserving erectile function, who are prepared to accept a higher risk of ED after surgery, plaque excision with grafting is considered an acceptable surgical option.[14] Various types of graft options are available in the market, including autologous, nonautologous that is allografts (cadaveric fascia lata, dura mater, human pericardium, such as Tutoplast^®), xenografts (bovine/porcine pericardium, small intestinal submucosa, tissue-engineered sheep pericardium), and synthetic (Gore-Tex, TachoSil^®, and Dacron). Synthetic grafts are no longer used nowadays. Alternative autologous grafts (e.g., dermal, veins, buccal, temporalis fascia, tunica albuginea, or vaginalis) have been explored, but their availability and outcomes remain variable. Here, we used bovine pericardial grafts that are available in fixed sizes. It has shown advantages such as easy customizations and handling, less retraction, no antigenic reaction/immunogenicity, and avoiding donor site morbidity. However, current evidence does not definitively demonstrate that one type of graft is superior to another, and head-to-head comparisons regarding the type of graft have been made.[15] Recently, in a systematic review and meta-analysis, bovine pericardial graft use was found effective, safe, and feasible; the drawback is its additional cost.[16]

In developing countries where standard-sized grafts for PD may be cost-prohibitive, we have adapted them by customizing on-table bovine pericardium grafts to match the specific size of the defect. This approach involves tailoring the graft to fit the patient’s needs, including joining two or multiple graft pieces in a water-tight fashion. Here, we present our initial experience using the modified split graft technique using bovine pericardium after plaque excision in 12 patients with PD. The outcomes evaluated included the ability to perform sexual activity without difficulty, changes in curvature, length of penis, and overall satisfaction after the procedure. While bovine pericardial grafting is a well-established method, its cost remains prohibitive. This study introduces and explores a split graft technique to optimize the material use and reduce costs.

MATERIALS AND METHODS

This single-center, prospective study evaluated 12 patients undergoing plaque excision with bovine pericardium grafting over a follow-up period of 30 months. Our Institute Ethics Committee approved it (IMS/IEC/2024/7316). A single-experienced surgeon (more than 20 Peyronie’s surgeries) performed all procedures to maintain consistency in technique. The informed consent was obtained from all patients, ensuring they were fully aware of and agreed to the methods and potential outcomes. Before the surgical procedure, each patient underwent a comprehensive preoperative assessment, including history and physical examination, and the baseline data were recorded, including demographic details, location of the plaque (ventral, dorsal, lateral), curvature angle, comorbidities, and the Sexual Health Inventory for Men (SHIM) score for erectile function. The SHIM score was calculated individually for each patient, together with detailed information about their sexual health over the preceding month.[15]

The responses were used to calculate the SHIM score to measure erectile function quantitatively. The length of the penis was measured using the technique described by Wessells et al.[15] In the supine position, the penis was grasped from the glans and stretched at a 90°angle from the body. A hard scale was placed on the pubic bone, and the penile length was measured from the dorsal side to the meatus.

Usually, the graft is used as a whole patch to cover defects after the excision of plaque as it is available in the market in specified sizes like 4 cm × 4 cm, 4 cm × 6 cm, 4 cm × 16 cm, etc., Hence, a more considerable graft is required to cover a large, costlier area. In all patients, plaque excision and customization of on-table bovine pericardium graft according to the size of the defect and joining pieces of graft and tunica albuginea with PDS suture to cover the cavernosal defect. We usually post 2 or 3 patients in the operation theater for cost customization. A single surgeon conducted all surgeries. The size of the graft was measured during the procedure, and the result of the surgery was evaluated based on the change of penile curvature, length, and the ability to perform successful intercourse with or without the need for additional treatments (phosphodiesterase 5 inhibitors/prosthesis). Necrosis of the skin of the penis and glans, ischemia, edema, infection, and decrease of penile sensation was considered as postoperative complications.

Statistical analysis

The collected data were entered into an MS Excel sheet. Data were analyzed using IBM SPSS Statistics software version 28 is developed and distributed by International Business Machines Corporation (IBM), a globally recognized technology and consulting company headquartered in Armonk, New York, United States. IBM acquired the original developer, SPSS Inc., in 2009 and has since integrated the software into its analytics portfolio under the IBM brand. SPSS Statistics is a flagship product within IBM’s data science and analytics offerings, widely used for statistical analysis in academic, governmental, and commercial settings. The categorical variables were presented in numbers and percentages. The continuous variables were shown in mean ± standard deviation and interquartile range. The Z-test was used to test the significance percentage change in categorical variables, and the paired t-test was used to test the significance percentage change in mean values before and after surgery. P < 0.05 was considered statistically significant.

Surgical procedure and technique

All surgeries were performed under spinal anesthesia. Injection ceftriaxone sulbactam 1.5 gm i. v was given as an antibiotic just before the surgical incision in the operation theater. A Foley catheter of 16 Fr was inserted in the sterile field, and a sub-coronal incision was given to deglove the penis. The neurovascular bundle was carefully dissected and saved by bipolar cautery and sharp dissection. Next, an artificial erection was created by injecting saline into the corpus cavernosum to evaluate the penile curvature and size of the plaques. The plaques were then marked and removed using excision.[17] The graft was soaked in saline for at least 10 min to keep it moist. The size of the cavernosal defect resulting from plaque excision was then measured with a scale to determine the dimensions needed for graft coverage. The grafts were carefully trimmed or joined to be 2–3 mm, slightly larger than the defect, as required, to ensure complete defect coverage. Customized grafts were first secured at the corners and along the inter-cavernous septum. This method ensured that the grafts adhered firmly and adequately, and the graft fit and curvature were checked by injecting saline into the corpora cavernosa [Figure 1]. The penile fascia and skin were closed layer by layer, and a light-pressure dressing was applied. This dressing was then removed on the third postoperative day. Patients were advised to avoid sexual activity for 6 weeks and to have a penile massage at the night for 3 months. The remaining graft was used for the next patient and completely covered the defect. Suturing was then done continuously using a 4-0 PDS suture.

Figure 1.

Showing steps of plaque excision and bovine pericardial grafting: (a) Gittes test showed dorsal penile curvature, (b) Measurement of plaque size by scale, (c) Separation of neurovascular bundle from plaque, (d) Excision of complete plaque specimen by sharp dissection, (e) Grafts were sutured to each other and with tunica albuginea margins with PDS sutures and the defect was covered, (f) Straight penis after skin closure of circumcising incision

RESULTS

The mean age of the patients was 48 years (37–59). The most common comorbidity was hypertension, present in 4 out of 12 patients, followed by high cholesterol in 2 out of 12 patients, and diabetes mellitus in 1 out of 12. The location of the plaque was on the dorsal surface of the penis in 9 patients (75%) and on the lateral surface in 3 patients (25%). The curvature angle ranges from 34° to 56°, with an average of 45 ± 2°. The average plaque size was 4.6 cm, ranging from 1.5 to 8 cm. There was no significant difference in the size of the dorsal versus lateral plaque, as the P = 0.80. The mean stretched penile length (SPL) before the surgery was 10.4 ± 2.4 cm. Preoperative patient details are summarized in Table 1.

Table 1.

Preoperative variables and characteristics of the patients of Peyronie’s disease (n=12)

Variables	Number (%)
Age (years), mean±SD (IQR)	48±6.82 (37–59)
Co-morbidities
Hypertension	4 (33.30)
High cholesterol	2 (16.67)
Diabetes mellitus	1 (8.33)
Characteristics of the plaque
Dorsal	9 (75)
Lateral	3 (25)
Mean overall plaque size (cm)	4.6±1.73 (1.5–8)
Size of dorsal plaque	4.5±1.89
Size of lateral plaque	4.84±1.44
Dorsal versus lateral (P)	0.80
The mean angle of the curvature±SD (IQR) (°)	45±7.1 (34–56)
Mean SPL±SD (IQR) (cm)	10.4±1.29 (8.1–3.1)

SD: Standard deviation, IQR: Interquartile range, SPL: Stretched penile length

All patients’ mean follow-up duration was 30 months (range 3 to 57). The follow-up results are detailed in Table 2. By the end of the follow-up period, no residual penile curvature was observed in 10 patients (83.5%), while two patients (16.5%) had a curvature of <20°. All patients experienced an improvement in SPL, with an average increase of 1.6 cm, which was significant (P < 0.001). 9 out of 12 patients were able to perform sexual activity without assistance after 3 months. One patient, who had a sizeable cavernosal defect of 8 cm × 2 cm, experienced severe postoperative ED along with residual penile curvature of 15° and required semi-rigid penile prosthesis. Two patients having mild ED was managed by Tadalafil 10mg. Another patient with residual chordee of <20° was managed on conservative therapy. No tissue rejection, infection, or patch retraction cases were observed in any of the patients.

Table 2.

Clinical outcomes after excision of the plaque and bovine pericardium grafting

Variables	Number (%)
Residual curvature (%) <20	2/12 (16.5)
Complete penile straightening (%)	10/12 (83.5)
P	<0.001
Z	1.477
Mean SPL after surgery±SD (IQR) (cm)	11.6±1.68 (8.4–14)
Change in penile length after surgery (P)	<0.001
No ED (%)	9/12 (75)
PDE 5 inhibitors (%)	2/12 (16.5)
Penile prosthesis (%)	1/12 (8.5)
P
Z	<0.001
Satisfaction with the procedure
Yes (%)	10/12 (83.5)
No (%)	2/12 (16.5)

PDE 5: Phosphodiesterase 5, ED: Erectile dysfunction, SD: Standard deviation, IQR: Interquartile range, SPL: Stretched penile length

DISCUSSION

PD poses significant challenges and trauma for affected individuals, impacting both the physical and psychological aspects of their lives. The condition’s etiology, which includes trauma and idiopathic factors, contributes to penile curvature, plaques, and associated complications like ED.[18] There are different types of grafting materials available in the market, which can be grouped into three categories: autologous grafts (from the same person), allograft/xenograft (from a donor or another species), and synthetic grafts (artificial materials). There is no substantial proof that one type is better than the others. The best graft material should be easy to work with, strong, available commonly, low-risk for infection/rejection, cause slight inflammation, and have minimal chances of triggering an immune response. It should also be available in various sizes and be reasonably priced.[19] While multiple treatment options exist, surgical intervention remains the gold standard for patients with significant penile deformities precluding sexual intercourse. This study presents our initial experience with a modified split graft technique utilizing bovine pericardium, which is particularly suited for the resource-constrained settings.

The study’s findings provide valuable insights into a cost-effective surgical approach tailored for PD patients in regions where standard graft options might be economically prohibitive and part of the graft is wasted. Customizing bovine pericardium grafts to match individual defect sizes offers a viable solution for managing penile curvature and associated deformities. Moreover, the study demonstrates favorable outcomes in terms of complete penile straightening and increased penile length in 83.5% of patients and satisfactory sexual function restoration requiring no auxiliary treatment in 75% of patients postoperatively. These results are comparable and corroborating to previous studies, for example, a survey conducted by Otero et al. using lyophilized bovine pericardial graft after plaque excision in 41 patients. They found that 33 patients (80.5%) got complete penile straightening while five patients (12.2%) had residual curvature <20°. The penile length increased from 11.2 ± 2.8 cm to 12.1 ± 2.9 cm. Similar to our study, 75% of patients reported regular successful intercourse without further treatment.[20]

A recent meta-analysis showed that compared to the use of different grafts in PD, the buccal mucosal graft was found to be the most effective for treating the curvature of the penis, but the requirement for low preoperative curvature in buccal mucosal graft offsets this effect. On the other hand, the TachoSil graft performed best when the severity of preoperative curvature was considered.[21] A different study by Kovac and Brock, which followed patients for a longer time and looked at dermal, pericardial, and tiny small intestinal submucosal grafts, found that 60% of patients with dermal grafts reported their curvature improved. In comparison, 100% of those with pericardial (Tutoplast) grafts and 76.9% of small intestinal submucosal (Stratasis) graft recipients reported the same. Patients with Stratasis grafts also kept their presurgery length and significantly improved erectile function and rigidity better than the others.[22] Levine and Estrada used human cadaveric pericardium and showed success rates of 98% and 95% for straightening the penis and successful intercourse, respectively. Among patients achieving sexual intercourse, 75% had full sexual intercourse without treatment, while 30% of patients required some medication for intercourse.[23] Hellstrom and Reddy also reported that all 11 patients in their study had resolution of penile curvature and regular intercourse after plaque excision and grafting with Tutoplast at a follow-up of 14 months.[24]

In a recent paper, Eslahi et al. compared plaque excision with testicular tunica vaginalis grafts with bovine pericardium grafts. They found that both types of grafts are equally effective in correcting clinically significant PD.[25] Similarly, the safety of the bovine pericardial graft has been compared with that of the porcine dermal graft in plaque incision and grafting procedure.[26] They showed equal long-term outcomes. When comparing bovine and human pericardial grafts regarding de novo ED, the bovine graft showed better performance.[27] The European Society for Sexual Medicine has also reported high satisfaction rates following surgery with bovine pericardium grafts.[28]

Although literature regarding the long-term durability and fibrosis of bovine pericardial graft is scarce, it is durable. However, fibrosis or contracture may occur on the long-term follow-up due to tissue response causing scarring. Studies have shown improved patient-reported satisfaction or quality of life after bovine pericardial graft surgery. Otero et al. found that 75% of patients had successful intercourse without additional treatment and 85% of patients were satisfied with the treatment and will opt for surgery again.[20] In another study by Silva-Garretón et al., 21 out of 28 patients (75%) expressed satisfaction with the surgery.[27] The issue remains its cost, especially in developing countries. Our modified split graft technique uses bovine pericardium after plaque excision and judiciously uses graft material. It saves extra nonused graft material, which can be used in another patient without affecting the procedure’s success rate. The study’s retrospective design, with a limited follow-up period of 14 months and a modest sample size of 12 patients, reflects the preliminary nature of the study. While the results are promising, further prospective randomized studies with more patients and extended follow-up periods are warranted to validate this modified graft technique’s efficacy and long-term outcomes. In addition, comparative studies evaluating this approach against conventional grafting methods would provide valuable insights into its superiority and cost-effectiveness. Despite the promising results, several other limitations and challenges should be acknowledged. The absence of a control group limits the study’s ability to draw definitive conclusions regarding the efficacy and safety of the proposed technique. Moreover, the lack of standardized outcome measures and subjective satisfaction assessment may introduce the bias into the results. Addressing these limitations through rigorous study designs and standardized outcome assessments would enhance the robustness of future research in this area. Further research is needed to refine and optimize the modified graft technique, exploring factors such as graft compatibility, tissue integration, and long-term durability. Comparative studies evaluating different graft materials and techniques would shed further light on their relative efficacy and cost-effectiveness. In addition, assessing patient-reported outcomes and quality-of-life/cost-effective measures would enhance our understanding of the intervention’s broader impact on patients’ well-being.

CONCLUSION

This modified split graft technique provides a cost-effective and safe alternative with comparable outcomes to standard methods, reducing the wastage of graft material for managing PD-associated penile curvature. While promising, this technique requires further validation in more extensive, randomized controlled trials comparing it to conventional grafting approaches to confirm its efficacy and cost benefits. Future studies should assess the structural integrity of the graft and potential risks of fibrosis or contracture over extended follow-up periods. In addition to objective outcomes, patient-reported quality of life and satisfaction scores should be evaluated in future research. While further research is needed to validate its long-term efficacy and safety, the initial results suggest favorable outcomes regarding improved penile function and patient satisfaction. This technique seems to hold significant potential to address the unmet needs of PD patients, offering a feasible alternative to conventional grafting methods.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.