Multiphoton Imaging and Laser Ablation of Rodent Spermatic Cord Nerves: Potential Treatment for Patients With Chronic Orchialgia

Stripping versus ligation of vas deferens in microscopic denervation of spermatic cord in men with chronic orchialgia: A multicenter study

BACKGROUND

Microdenervation of the spermatic cord (MSCD) is an effective treatment modality for men with intractable scrotal content pain. For patients not interested in preserving fertility, some centers advocate ligation of the vas during denervation, while others prefer stripping of the vas deferens to preserve the vasal artery, hence preserving vasculature to the testis and possibly decreasing post-operative congestion pain.

OBJECTIVE

To compare outcomes of patients with chronic orchialgia, who underwent MSCD by either stripping or ligating the vas deferens.

MATERIALS AND METHODS

A retrospective chart review of 85 patients who underwent MSCD from 2017-2023 was performed. Patients' demographics including history of prior surgical procedures were recorded. Response to surgery was evaluated as either complete resolution of pain, partial resolution of pain, or no improvement in pain.

RESULTS

Eighty-five patients underwent MSCD with a median (interquartile range, IQR) age of 36 (25.5-46.5) years and median duration of pain of 16 (6-31) months. Thirty-seven patients underwent stripping of vas, while 48 underwent ligation of vas during MSCD. Median follow up was 12 months. Twenty-one (43.5%) patients had prior inguinal scrotal surgery in the ligation group compared to 5 (13.5%) in the stripping group, p = 0.003. The etiology of pain was similar between the groups. The response to MSCD between the two groups was similar, 67.6% of patients who underwent stripping had complete resolution of pain versus 66.7% of those who had ligation (p = 0.968), with similar rates of post-operative complications (p-value = 0.132).

CONCLUSIONS

In men with intractable chronic scrotal content pain with no interest in preserving fertility, ligation, or stripping of the vas deferens yields similar outcomes with regard to pain resolution. Both techniques are safe with no reports of any testicular atrophy.

Microsurgical Denervation of the Spermatic Cord: A Historical Perspective and Recent Developments

INTRODUCTION

The management of chronic scrotal pain is long and varied, with historical treatment algorithms typically ending with orchiectomy. Microsurgical denervation of the spermatic cord (MDSC) is a testicle-sparing option for patients who have failed conservative treatment options and over its forty-year history has seen many technical refinements.

OBJECTIVES

To review the history and development of MDSC and discuss the outcomes of different surgical techniques.

METHODS

A literature review using PubMed and Google Scholar was conducted to identify studies pertaining to surgical treatment of CSP, MDSC, and outcomes. Search terms included "chronic," "scrotal pain," "orchialgia," "spermatic cord," "denervation," and "microsurgery."

RESULTS

We included 21 case reports and series since the first seminal paper describing MDSC technique in 1978. Additional studies that challenged existing conventions or described novel techniques are also discussed. The current standard procedure utilizes a subinguinal incision and a surgical microscope. Open, robotic, and laparoscopic approaches to MDSC have been described, but access to minimally invasive instruments may be limited outside of developed nations. Pain reduction following preoperative spermatic cord predicts success of MDSC. Methods for identifying and preserving the testicular and deferential arteries vary depending on surgeon preference but appear to have comparable outcomes. Future developments in MDSC involve targeted denervation, minimizing collateral thermal injury, and alternative techniques to visualize arterial supply.

CONCLUSION

For patients suffering from CSP, MDSC is a well-studied technique that may offer appropriately selected patients' relief. Future investigation comparing targeted vs full MDSC as well as in vivo study of new techniques are needed to continue to improve outcomes. Sun HH, Tay KS, Jesse E, et al. Microsurgical Denervation of the Spermatic Cord: A Historical Perspective and Recent Developments. Sex Med Rev 2022;XX:XXX-XXX.

Technological Advancements in Male Infertility Microsurgery

There have been significant advancements in male infertility microsurgery over time, and there continues to be significant promise for new and emerging techniques, technologies, and methodologies. In this review, we discuss the history of male infertility and the evolution of microsurgery, the essential role of education and training in male infertility microsurgery, and new technologies in this space. We also review the potentially important role of artificial intelligence (AI) in male infertility and microsurgery.

Current trends and therapies in orchialgia management

The management of pain is a complex condition that will be encountered by most practicing clinicians. In the genitourinary community, testicular pain may be classified as acute or chronic. Initial evaluation of chronic groin and scrotal content pain (CGSCP) begins with a detailed history and physical examination to elucidate the presenting pathology. Multiple therapy algorithms have been proposed with no definitive consensus; however, most begin with conservative intervention and medical management prior to advancing to more invasive procedures. Surgical approaches may range from reconstruction, as in vasovasostomy for post-vasectomy pain syndrome, to excision of the offending agent, as in epididymectomy. This review seeks to focus on chronic pain in the genitourinary community and review techniques of pain management in the current intervention for orchialgia, as well as identify future methods of treatment.

Hydrodissection for improved microsurgical denervation of the spermatic cord: prospective blinded randomized control trial in a rat model

Microsurgical denervation of the spermatic cord (MDSC) can provide up to an 86% improvement in pain in patients with chronic orchialgia (CO) who have failed conservative management. Failures in MDSC could be due to small diameter nerves (≤1 mm) left behind on the spermatic cord. The objective of this study was to assess if hydrodissection (HD) of the spermatic cord after MDSC could decrease the number of residual nerve fibers without compromising blood flow. Prospective blinded randomized control trial: bilateral MDSC was performed on 22 adult rats (44 cords). HD of the spermatic cord was performed on one side of each rat (side randomized) using the ERBEJET2. The contralateral cord (no HD) was the control for each animal. Blood flow through the vessels was monitored using a micro-Doppler probe. After completion a cross-section of the residual cord was sent to pathology (blinded to technique) to assess for small diameter nerves and signs of damage in vascular integrity. Blood flow had been maintained in the vessels when the ERBEJET2 was set to 6 bar (87 psi). The cord where HD had been performed had a significantly lower total median residual nerve count of 5 (0-10), compared to 8 (2-12) on the non-HD side (p = 0.007). No structural damage was seen in the vessels in the spermatic cord that had undergone HD (gross exam and histology). HD of the spermatic cord significantly decreases residual nerve density without compromising vascular integrity in a rat model.

Prospective control trial: flexible CO2 laser vs. monopolar electrocautery for robotic microsurgical denervation of the spermatic cord

Microsurgical denervation of the spermatic cord (MDSC) is a treatment option in patients with chronic orchialgia. This procedure requires precise care to avoid any thermal damage to crucial adjacent tissues (arteries, veins, and lymphatics). Monopolar electrocautery is the standard ligation energy source, but may cause extensive collateral damage to the tissues. However, CO₂ laser is known to produce a very predictable tissue penetration and minimal collateral spread. The goal of this study was to compare the extent of collateral thermal damage in both monopolar electrocautery and CO₂ laser ablation in the spermatic cord during a robotic assisted MDSC (RMDSC) procedure as well as the feasibility for utilizing the flexible fiber-optic CO₂ laser probe after "RMDSC" procedure. RMDSC was performed using standard monopolar electrocautery on the spermatic cord of one side of a fresh human male cadaver (randomly selected) and then compared to RMDSC using the CO₂ laser on the contralateral spermatic cord. Nine histological cross-sections from each cord were measured for depth of collateral thermal/cautery injury. The mean collateral thermal injury with CO₂ laser was 0.17 ± 0.031 mm (range: 0.15-0.25 mm), and with standard electrocautery 0.72 ± 0.046 mm (range: 0.60-0.75 mm). CO₂ laser resulted significantly less collateral thermal injury than standard electrocautery (p < 0.0001). The CO₂ laser probe was easy to manipulate with the Black Diamond micro-forceps (Intuitive Surgical, CA) and allowed for convenient tissue plane dissection. Human cadaveric targeted RMDSC using a flexible CO₂ laser energy results in significantly decreased collateral thermal injury compared to standard monopolar electrocautery. These initial findings suggest potential advantages of the CO₂ laser over traditional monopolar cautery in cases requiring minimal collateral tissue damage. Future studies are needed to assess its clinical potential in microsurgery.

Microsurgical denervation of rat spermatic cord: safety and efficacy data

OBJECTIVE

To describe a microsurgical technique for denervation of the spermatic cord and use of multiphoton microscopy (MPM) laser to identify and ablate residual nerves after microsurgical denervation. To evaluate structural and functional changes in the rat testis and vas deferens after denervation.

MATERIALS AND METHODS

Nine Sprague-Dawley rats were divided into three experimental groups: sham, microsurgical denervation of the spermatic cord (MDSC), and MDSC immediately followed by laser ablation with MPM. At 2 months after surgery, we assessed testicular volume, functional circulation of the testicular artery with Doppler, patency of the vas deferens, and histology of the testis and vas deferens.

RESULTS

There was a significant decrease in the median number of nerves remaining around the vas deferens with MDSC alone (3.5 nerves) or MDSC with MPM (1.5 nerves) compared with sham rats (15.5 nerves) (P = 0.003). Although, MDSC with MPM resulted in the fewest remaining nerves, this result was similar to MDSC alone (P = 0.29). No deleterious effects on spermatogenesis or vas patency were seen in the experimental groups when compared with the sham rats.

CONCLUSION

A microsurgical approach can be used to effectively and safely denervate the rat spermatic cord with minimal changes to structure and function of the testis and vas deferens. MPM can be used as an adjunct to identify and ablate residual nerves after MDSC.

Robotic-assisted microsurgery for an elective microsurgical practice

Robotic-assisted microsurgery can be utilized for either intracorporal or extracorporeal surgical procedures. Three-dimensional high-definition magnification, a stable ergonomic platform, elimination of physiologic tremor, and motion scaling make the robotic platform attractive for microsurgeons for complex procedures. Additionally, robotic assistance enables the microsurgeon to take microsurgery to challenging intracorporeal locations in a minimally invasive manner. Recent adjunctive technological developments offer the robotic platform enhanced optical magnification, improved intraoperative imaging, and more precise ablation techniques for microsurgical procedures. The authors present the current state-of-the art tools available in the robotic-assisted microsurgical platform.

Multiphoton microscopy: a potential "optical biopsy" tool for real-time evaluation of lung tumors without the need for exogenous contrast agents

CONTEXT

Multiphoton microscopy (MPM) is an emerging, nonlinear, optical-biopsy technique, which can generate subcellular-resolution images from unprocessed and unstained tissue in real time.

OBJECTIVE

To assess the potential of MPM for lung tumor diagnosis.

DESIGN

Fresh sections from tumor and adjacent nonneoplastic lung were imaged with MPM and then compared with corresponding hematoxylin-eosin slides.

RESULTS

Alveoli, bronchi, blood vessels, pleura, smokers' macrophages, and lymphocytes were readily identified with MPM in nonneoplastic tissue. Atypical adenomatous hyperplasia (a preinvasive lesion) was identified in tissue adjacent to the tumor in one case. Of the 25 tumor specimens used for blinded pathologic diagnosis, 23 were diagnosable with MPM. Of these 23 cases, all but one adenocarcinoma (15 of 16; 94%) was correctly diagnosed on MPM, along with their histologic patterns. For squamous cell carcinoma, 4 of 7 specimens (57%) were correctly diagnosed. For the remaining 3 squamous cell carcinoma specimens, the solid pattern was correctly diagnosed in 2 additional cases (29%), but it was not possible to distinguish the squamous cell carcinoma from adenocarcinoma. The other squamous cell carcinoma specimen (1 of 7; 14%) was misdiagnosed as adenocarcinoma because of pseudogland formation. Invasive adenocarcinomas with acinar and solid pattern showed statistically significant increases in collagen. Interobserver agreement for collagen quantification (among 3 observers) was 80%.

CONCLUSIONS

Our pilot study provides a proof of principle that MPM can differentiate neoplastic from nonneoplastic lung tissue and identify tumor subtypes. If confirmed in a future, larger study, we foresee real-time intraoperative applications of MPM, using miniaturized instruments for directing lung biopsies, assessing their adequacy for subsequent histopathologic analysis or banking, and evaluating surgical margins in limited lung resections.

Trifecta nerve complex: potential anatomical basis for microsurgical denervation of the spermatic cord for chronic orchialgia

PURPOSE

We identified structural abnormalities in the spermatic cord nerves that may explain how microsurgical denervation of the spermatic cord provides pain relief in patients with chronic orchialgia.

MATERIALS AND METHODS

We retrospectively reviewed a prospective database to compare spermatic cord biopsy specimens from 56 men treated with a total of 57 procedures for microsurgical denervation of the spermatic cord for chronic orchialgia vs a control group of men without pain treated with cord surgery, including varicocelectomy in 4 and radical orchiectomy in 6. Tissue biopsies were obtained from mapped regions of the spermatic cord in all cases. Biopsies stained with hematoxylin and eosin were examined by an independent pathologist. Three human cadaveric spermatic cords were dissected to confirm localization of the nerve distribution identified on pathological mapping.

RESULTS

We identified a median of 25 small diameter (less than 1 mm) nerve fibers in the spermatic cord. Of the 57 procedures for orchialgia 48 (84%) showed wallerian degeneration in 1 or more of these nerves but only 2 of 10 controls (20%) had such degeneration (p = 0.0008). In decreasing order of nerve density the 3 primary sites (trifecta nerve complex) of these changes were the cremasteric muscle fibers (19 nerves per patient), perivasal tissues and vasal sheath (9 nerves per patient), and posterior cord lipomatous/perivessel tissues (3 nerves per patient). Cord nerve distribution mapped by the biopsies was confirmed by cadaveric dissection.

CONCLUSIONS

In men with chronic orchialgia there appears to be wallerian degeneration in reproducible patterns in the spermatic cord nerve fibers. Transection of these nerves may explain the effect of the denervation procedure.

Multiphoton tomographic imaging: a potential optical biopsy tool for detecting gastrointestinal inflammation and neoplasia

Endoscopy is widely used to detect and remove premalignant lesions with the goal of preventing gastrointestinal (GI) cancers. Because current endoscopes do not provide cellular resolution, all suspicious lesions are biopsied and subjected to histologic evaluation. Technologies that facilitate directed biopsies should decrease both procedure-related morbidity and cost. Here we explore the use of multiphoton microscopy (MPM), an optical biopsy tool that relies on intrinsic tissue emissions, to evaluate pathology in both experimental and human GI specimens, using hematoxylin and eosin (H&E)-stained sections from these tissues for comparison. After evaluating the entire normal mouse GI tract, MPM was used to investigate disease progression in mouse models of colitis and colorectal carcinogenesis. MPM provided sufficient histologic detail to identify all relevant substructures in ex vivo normal GI tissue, visualize both acute and resolving stages of colitis, and show the progression of colorectal carcinogenesis. Next, ex vivo specimens from human subjects with celiac sprue, inflammatory bowel disease, and colorectal neoplasia were imaged by MPM. Finally, colonic mucosa in live anesthetized rats was imaged in vivo using a flexible endoscope prototype. In both animal models and human specimens, MPM images showed a striking similarity to the results of H&E staining, as shown by the 100% concordance achieved by the study pathologists' diagnoses. In summary, MPM is a promising technique that accurately visualizes histology in fresh, unstained tissues. Our findings support the continued development of MPM as a technology to enhance the early detection of GI pathologies including premalignant lesions.

Factors predicting symptomatic relief by varicocelectomy in patients with normospermia and painful varicocele nonresponsive to conservative treatment

OBJECTIVE

To assess the factors predicting symptomatic relief by varicocelectomy in patients with normospermia and painful varicocele nonresponsive to conservative treatment.

METHODS

A total of 76 men with left painful varicocele and normal semen quality were recruited for the present prospective study. The patients who showed complete or partial resolution of pain 6 months after varicocelectomy were designated as responders, and those who did not have improvement were designated as nonresponders. The predictive factors examined included the number of ligated veins, preoperative pain score, duration of pain, body mass index, scrotal temperature, the distance from the renal hilum to the scrotum, the serum concentration of follicle-stimulating hormone, luteinizing hormone, and testosterone, grade of varicocele, peak retrograde flow, and maximal vein diameter on color Doppler ultrasound scans.

RESULTS

Of the 76 patients, 55 (72.4%) were responders and 21 (27.6%) were nonresponders, with a mean age of 31.8 and 32.4 years, respectively. The responders had a significantly greater number of ligated veins, preoperative pain score, and longer duration of pain than the nonresponders. No significant differences were found in body mass index, scrotal temperature, distance from the renal hilum to the scrotum, peak retrograde flow, follicle-stimulating hormone, luteinizing hormone, testosterone, and maximal vein diameter between the responders and nonresponders.

CONCLUSION

The findings of the present study suggest that the factors predicting symptomatic relief by varicocelectomy in patients with normospermia and painful varicocele nonresponsive to conservative treatment are a greater number of ligated veins (>7), greater preoperative pain score (>6), and longer duration of pain (>9 months).