Transcutaneous Neuromuscular Electrical Stimulation for Treating Varicocele-Induced Scrotal Pain

Summary

This protocol outlines the use of transcutaneous neuromuscular electrical stimulation for treating varicocele-induced scrotal pain. It compares visual analog scale (VAS) scores and imaging changes before and after treatment to assess effectiveness. Results indicate that patients experienced improved scrotal pain symptoms following the treatment.

Abstract

Varicocele is a prevalent vascular disorder affecting the male reproductive system, leading to scrotal pain and testicular dysfunction. Epidemiological studies have shown that varicocele occurs in approximately 10% to 15% of adult males, while scrotal pain affects 2% to 10% of the population. Currently, clinical treatment options for varicocele-induced scrotal pain include general therapy, medication, and surgery. Among these, surgical intervention is considered the most effective method, boasting a success rate of 80%. However, it carries risks such as postoperative bleeding, infection, and recurrence, making it less desirable for some patients. In recent years, transcutaneous neuromuscular electrical stimulation has gained wide acceptance for treating various andrological conditions, including erectile dysfunction and premature ejaculation, yielding positive outcomes. This non-invasive technique offers a promising alternative for managing varicocele-induced scrotal pain, potentially reducing the need for surgical intervention and its associated risks. Its growing popularity underscores the need for further research and clinical trials to validate its efficacy and safety in treating this condition.

Introduction

Varicocele is a prevalent vascular abnormality affecting the male reproductive system, characterized by the enlargement, elongation, and tortuosity of the spermatic cord's venous plexus. It often leads to scrotal pain, discomfort, and progressive testicular hypogonadism, and is a major contributing factor to male infertility. Epidemiological studies have shown that varicocele affects approximately 10% to 15% of adult males. Among infertile men, the prevalence of varicocele can reach 40%, and scrotal pain occurs in 2% to 10% of cases¹.

Varicose veins commonly occur on the left side of the spermatic cord, which can be attributed to two primary factors. Firstly, the left spermatic vein is anatomically longer than the right spermatic vein. Secondly, the right spermatic vein connects to the inferior vena cava, experiencing lower pressure, whereas the left spermatic vein joins the left renal vein at a right angle, resulting in higher pressure². Increased venous pressure in the left renal vein, situated between the abdominal aorta and the superior mesenteric artery, leads to elevated pressure within the corresponding spermatic vein³.

The exact mechanism underlying scrotal pain in varicocele remains unclear. Potential contributing factors include elevated testicular temperature, oxidative stress, testicular hypoxic injury, endocrine dysregulation, and the influence of renal/adrenal metabolic toxins. These factors stimulate receptors, triggering the generation of action potentials that propagate through neural pathways within the spinal cord, ultimately transmitting electrical signals to the brain via the thalamic tracts located on the medial and posterior aspects of the spinal cord, resulting in pain perception⁴.

Clinical treatments for scrotal pain associated with varicocele encompass general measures, medication, and surgical interventions. General treatment involves lifestyle and dietary adjustments, which can provide some degree of symptom reduction. Pharmacological approaches often include the administration of hepatic saponins, such as Aescuven Forte, which exhibit anti-inflammatory and anti-exudative properties and help maintain the structural integrity of venous walls, particularly collagen fibers⁵. Treatment with hepatic saponins, such as Aescuven Forte, gradually restores the elasticity and contractile function of venous walls, thereby increasing venous blood reflux rate, reducing venous pressure, and alleviating symptoms like scrotal discomfort. Flavonoids and non-steroidal anti-inflammatory drugs are other commonly employed therapeutic agents that offer some efficacy in improving scrotal pain symptoms. Although physical cooling and scrotal rest have been utilized for varicocele-associated scrotal pain, their usage is limited due to decreased patient acceptance⁶.

Surgical interventions, such as open surgery, laparoscopic surgery, microscopic surgery, and interventional surgery, are commonly selected for patients with varicocele who experience more pronounced scrotal pain symptoms or infertility. Surgical treatment is currently regarded as the most effective approach, achieving up to an 80% success rate in relieving pain symptoms. However, it is important to acknowledge potential postoperative complications, including bleeding, wound infection, testicular sheath effusion, and testicular atrophy. Regardless of the surgical method chosen, the recurrence rate of varicocele ranges from 1.9% to 17.2%⁷.

Transcutaneous electrical nerve stimulation (TENS) is an extensively employed non-invasive physical therapy that applies electrical stimulation to the skin's surface, leading to pain relief and enhanced nerve function. By transmitting electrical currents through electrodes into nerve tissue, TENS influences nerve activity and finds widespread applications, including: (1) Pain relief: TENS effectively alleviates various types of pain, including muscle pain, neuralgia, and joint pain. The stimulation of nerve endings through TENS promotes the secretion of natural pain-relieving substances, such as endorphins, thereby reducing pain; (2) Rehabilitation training: TENS serves as a valuable tool in rehabilitation training, aiding in the restoration of impaired muscle and nerve function. For instance, after a sports injury, TENS can be used to alleviate pain and facilitate the recovery process; (3) Neuromodulation: TENS is also utilized for neuromodulation purposes, such as managing symptoms associated with urinary incontinence and constipation⁸.

The diverse therapeutic potential of transcutaneous electrical nerve stimulation (TENS) in pain management, rehabilitation, and neuromodulation highlights its efficacy and applicability. Through the stimulation of nerve endings, TENS promotes desirable neuromuscular responses, effectively ameliorating associated symptoms. Notably, TENS has demonstrated favorable efficacy in addressing male conditions such as erectile dysfunction and premature ejaculation. Patients readily embrace TENS due to its advantageous features of safety, reliability, and affordability. Furthermore, TENS treatment for venous vascular diseases yields beneficial outcomes, including pain relief, enhanced blood flow, and expedited wound healing⁹.

This study utilizes electrophysiological therapy-related technology to examine the effectiveness of transcutaneous neuromuscular electrical stimulation in alleviating scrotal pain associated with varicocele. The findings of this investigation have the potential to offer a valuable alternative treatment approach for individuals experiencing varicocele-related scrotal pain.

Protocol

Prior to implementation, the Institutional Review Board of The Northern Jiangsu People's Hospital thoroughly assessed and granted approval for all procedures detailed in the subsequent protocol. In this study, patients are provided with comprehensive explanations of the processes involved, and their informed consent is duly obtained before employing electrophysiological technology for diagnostic and therapeutic purposes. The details of the reagents and equipment used are listed in the Table of Materials.

1. Patient selection

1. Set the following inclusion criteria
   1. Based on the established reference standard⁷ for varicocele using color Doppler flow imaging (CFDI), identify clinical varicocele by the presence of at least three spermatic veins within the spermatic venous plexus during a relaxed state. Confirm that one of these veins has an internal diameter exceeding 2.2 mm or shows a significant increase in diameter when abdominal pressure is applied.
      1. Assess evident reflux of venous blood flow following the Valsalva test as another indicative factor for varicocele¹⁰. Look for symptoms related to scrotal pain.
   2. Ensure the subject is aged 18 to 50 years old.
   3. Confirm that the subject has not taken any medication for varicocele treatment in the last month.
2. Set the following exclusion criteria
   1. Exclude secondary varicocele.
   2. Exclude individuals with orchitis, epididymitis, or syringomyelia¹¹.
   3. Exclude individuals with metallic medical stimulators (e.g., pacemakers) in the body.
   4. Exclude those who are allergic to skin electrode materials.
   5. Exclude those with broken skin at the treatment site.

2. Diagnosis and treatment process

NOTE: Anesthetization is not required for this procedure.

1. Pre-examination preparation
   1. Have the patient sit still or lie flat to rest for 15 min.
   2. Ask the patient to enter the examination compartment, remove all clothing, and face the scanner (Figure 1).
   3. Ask the patient to follow the system voice instructions for movements. Click on Freeze (Figure 2) on the operation side to save the image (performed by the doctor).
      NOTE: The system utilizes infrared thermal imaging combined with a recorder. Instructions include raising arms to capture armpits or turning backward to capture the back. No questions are asked.
2. Finding the abnormal temperature area
   1. Move the mouse to the testicles in the patient's action screen. Observe the abnormal body temperature region. The normal temperature region is displayed in yellow, the high-temperature region in red, and the low-temperature region in green (Figure 3).
      NOTE: Abnormal body temperature areas in patients with varicocele are often found in the inguinal area and the testis on the affected side.
   2. Subtract the temperature of the healthy testis from the temperature of the affected testis to obtain the bilateral scrotal temperature difference.

3. Concluding the treatment

1. Apply electrode pads to the patient's abdomen and bilateral inguinal regions.
2. Adjust the current intensity and pulse width (4 Hz, 400 µs) on the electrode pads to levels acceptable to the patient.
3. Record the current intensity and pulse width at which the area of temperature abnormality on the scanner returns to normal.
4. Locate the treatment protocol in the system that corresponds to the recorded current intensity and pulse width.
5. Input the treatment protocol into the removable low-frequency neuromuscular therapy device. Guide the patient through the treatment, selecting appropriate parameters within a frequency range of 1-400 Hz and a pulse width of 50-1000 µs.

4. Patient follow-up steps

1. Arrange for the patient to return for follow-up visits to monitor progress and assess the effectiveness of the treatment.
2. Instruct the patient to report any changes in symptoms, including improvements or new discomfort, during follow-up appointments.
3. Perform follow-up imaging to evaluate the status of the varicocele and ensure the treatment has had the desired effect.
4. Based on the follow-up imaging and symptom reports, adjust the treatment plan as needed to optimize outcomes.
5. Review the patient's treatment progress and document all findings and changes in their medical record.
6. Offer guidance on managing symptoms, lifestyle changes, and any additional treatments or therapies that may be required.
7. Evaluate the patient for any side effects or complications resulting from the treatment and address them promptly.

Results

The current protocol outlines the use of transcutaneous neuromuscular electrical stimulation for treating varicocele-induced scrotal pain. The therapeutic equipment used by the patients is displayed in Figure 4. Eventually, 38 patients completed the treatment, and the following results were obtained after performing a normality test on the data (Table 1). The mean Visual Analog Scale (VAS) score¹² of the patients before treatment was 3.00 (3.00, 4.00)...

Discussion

The etiology of testicular pain in varicocele remains elusive, with potential mechanisms including increased testicular temperature, oxidative stress, testicular hypoxic injury, endocrine factors, and the involvement of renal/adrenal metabolic toxicity. When alternative causes of scrotal pain are excluded, and conservative treatment proves ineffective, surgical intervention becomes a crucial therapeutic approach for patients suffering from painful varicocele. Surgical techniques include retroperitoneal or inguinal approa...

Materials

Name	Company	Catalog Number	Comments
Low frequency neuromuscular therapy device	Foshan Shanshan Datang Medical Technology Company	BioStim pro	Detachable and portable therapeutic instruments
Medical infrared thermal imager	Foshan Shanshan Datang Medical Technology Company	PRISM 640A, PRISM 384A	Instrument for infrared thermal imaging scanning of the human body
Medical infrared thermal imaging system	Foshan Shanshan Datang Medical Technology Company	PRISM X 1.0.3	Medical infrared thermal imager supporting computer system
Surface electrodes for physical therapy	Foshan Shanshan Datang Medical Technology Company	JB50100, E6596, B50180	Electrode plate