Is there a role for botulinum toxin in inguinal hernia surgery? Case report on the management of a giant scrotal hernia

Giant scrotal hernias with loss of domain are relatively rare in countries with readily available medical care. Patients who eventually seek surgical help for this problem are typically elderly in our experience, socially challenged, medically undertreated, and have relevant comorbidities and increasing local symptoms.

Unless emergency repair is necessary due to strangulation, these patients may benefit from measures of prehabilitation targeting their individual general and hernia-specific risk factors. Eventually, however, reduction of the hernia sac’s content into the abdominal cavity will be necessary and, in the presence of loss of domain, this step is potentially associated with increased intra-abdominal pressure and organ injury as part of abdominal compartment syndrome (ACS). In order to avoid this, laparotomy or open [1, 2] or laparoscopic [3] surgical component separation of the abdominal wall’s lateral muscles and even organ resection [1] may be necessary.

All of these measures represent risks for additional morbidity and even mortality in these often already physiologically challenged patients, and should be avoided if possible. Prior to elective hernia repair, the intra-abdominal volume can generally be increased through either progressive pneumoperitoneum (PPP) [4, 5] or preconditioning of the lateral muscles of the abdominal wall with botulinum toxin A. [6] Both are routinely used in hernia centers for the repair of large ventral hernias. For giant scrotal hernias, preconditioning of the abdominal wall’s lateral muscles is less common. This is surprising, since the repair of giant scrotal hernias after preconditioning of the abdominal wall may not only cause less anatomical alterations in this region—which is one of the goals in ventral hernia repair—but may in fact avoid traumatic surgical procedures in the abdominal wall altogether.

The instillation of air into the abdominal cavity of these patients, however, will logically lead to distension of not only the abdomen but also of the scrotal hernia sac, which may potentially increase local symptoms in the inguinoscrotal region and decrease the effect on the lateral abdominal wall itself. Intramuscular injection of botulinum toxin A (BTA), on the other hand, will only affect the lateral abdominal muscles, without other anatomical side effects and was, therefore, the method of choice in the case described.

The 73-year-old male patient was 173 cm tall and weighed 83 kg (BMI: 27.7 kg/m²). On initial presentation, he was suffering from a right-sided hernia (pL3) and a left-sided, partially reducible hernia with loss of domain (pL3) without previous abdominal surgery (Fig. 1). Coexisting medical conditions included peripheral vascular disease of the legs, grade II mitral valve failure, grade II tricuspid valve failure, atrial fibrillation, arterial hypertension, and ongoing nicotine abuse. The latter was terminated 4 weeks before the first hernia repair. This was conducted by means of a Lichtenstein operation. Botulinum toxin A (BOTOX® 100 Allergan international units, Allergan Pharmaceuticals, Westport, Ireland) was then administered to the three muscles of the abdominal wall in five positions on either side under ultrasound guidance and after dilution in 30 ml of normal saline. A CT scan was performed, which showed a loss of domain of 43% (volumes: hernia sac: 3670 ml, hydrocele 623 ml, abdominal cavity 7051 ml). Five weeks later, surgery was performed on the giant scrotal hernia on the left side. Lichtenstein’s technique of repair was chosen for the patient over potentially applicable laparoscopic procedures in view of the very large hernia and the patient’s general frailty. After a minimal additional lateral incision of the deep inguinal ring, in order to facilitate reduction of the hernia sac’s content, followed by nonabsorbable suture reconstruction of the deep inguinal ring, the implant size was chosen with regard to the patients limited anatomical space. The spermatic cord and testicle remained intact and could be preserved.

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Upon initial presentation to our surgical outpatient clinic, the patient had been suffering from a bilateral hernia for almost 10 years. The left-sided scrotal hernia was giant and accompanied by a testicular hydrocele (Fig. 2), but he had noticed only moderate discomfort.

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After a thorough clinical examination by two surgeons with a specific interest in hernia surgery in a tertiary care facility’s dedicated hernia clinic, anesthesiologic examination, and clarification of the patient’s extensive preoperative risk profile, a CT scan of the abdomen, pelvis, and scrotum at rest and under the Valsalva maneuver was performed. The volume of the abdominal cavity and the hernia sac were calculated in accordance with Tanaka’s method and after axis correction, a score of 0.43 radiologically supported the already clinically clearly apparent loss of domain ([7]; Fig. 3a, b). Radiological axis correction for analyses was necessary because the original methodology of calculation according to Tanaka is only applicable to ventral hernias and since the radiological configuration of inguinal hernias is not of elliptic configuration like most vental hernias but instead rather pear shaped.

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The patient gave written informed consent to the scientific use of all case-associated data through participation in the international hernia register Herniamed and for all planned procedures: Lichtenstein hernia repair for the giant scrotal left-sided hernia after preoperative infiltration of the lateral abdominal wall muscles with botulinum toxin A (BOTOX® 100 Allergan international units) under ultrasound guidance in off-label use.

The right-sided smaller hernia (pL3) was treated 1 month later by means of a Lichtenstein operation, which was performed without any complications (Fig. 4).

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Subsequently, relaxation by means of botulinum toxin A (BOTOX® 100 Allergan international units) was planned to relax the abdominal wall sufficiently for the scheduled treatment of the much larger left-sided scrotal hernia. For preoperative optimization, especially for the creation of increased abdominal volume, a chemical myofascial relaxation with ultrasound-guided intramuscular infiltration of the three layers of the lateral abdominal wall muscles on both sides was performed with a total of 500 IU botulinum toxin A (BOTOX® 100 Allergan international units) divided into ten equal portions, which was the surgical unit‘s standard at that point in time and has since been reduced to 300 i.u. for this and similar indications. After uneventful observation overnight, the patient was discharged home. Five weeks later he was readmitted and underwent surgery for the left-sided giant scrotal hernia: after intraoperative placement of an indwelling urinary catheter, designed for monitoring the intra-abdominal pressure, the concomitant hydrocele in the left scrotum was drained and repaired with Winkelmann’s technique [8]. After herniotomy, the contents of the actual hernia sac could easily be reduced into the abdominal cavity. The detected hernia (EHS: pL3) was repaired with a self-gripping polypropylene implant (Covidien® Progrip 12 × 8 cm, PP1208D, Covidien/Medtronic, Devoux, France) with one additional, nonabsorbable suture fixation to the conjoint tendon in Lichtenstein’s technique [9]. Excessive scrotal skin was resected. Suction drains were placed in the scrotum and implant area for 3 days. The patient was transferred to the intermediate care unit for postoperative observation. Despite unsuspicious monitoring of his intra-abdominal pressure, the patient developed prerenal kidney failure, eventually attributed to overly restrictive intraoperative fluid management (Clavien–Dindo 3A) [10]. The condition was successfully managed conservatively by administration of crystalloid fluids.

After 3 days the patient was transferred to the surgical ward. On the 6th postoperative day, elevated inflammatory parameters were noted, which continued to increase until the 14th postoperative day, when redness and swelling in the scrotum area had appeared.

Follow-up was completed for 1 year without any evidence of complications or hernia recurrence. Shortly thereafter, the still cachectic patient died from an unrelated episode of pneumonia, associated with acute prerenal failure and septic shock.

The management of patients with giant scrotal hernias and their medical treatment is usually challenging, not only from a surgical/technical point of view, but also due to the frequently present multiple comorbidities and undiagnosed conditions in this oftentimes medically undertreated patient cohort.

Several open and laparoscopic repair options for hernia repair exist for this specific condition, which usually requires a multidisciplinary, team-based approach throughout its treatment. The early involvement of a dedicated hernia surgeon’s expertise, however, is essential [1‐3].

In order to avoid emergency procedures without any time for in-depth diagnosis and sufficient treatment of comorbidities in these challenging cases, it is essential to establish a tailored plan for this relatively small subset of hernia patients.

Prehabilitation of patients, optimization of risk factors, and preconditioning of the future surgical fields, if necessary, in as timely a manner as possible, includes the evaluation and correction of malnutrition and iron deficiency, optimization of antidiabetic treatment, reduction of excessive bodyweight, management of cardiovascular and pulmonary diseases, timely or permanent smoking cessation, bacteriologic or infectiologic screening, and meticulous planning of the actual surgical procedure.

Aside from all other factors influencing postoperative adverse events and outcomes, an additional risk for patients with large hernias associated with loss of domain is reflected by abdominal compartment syndrome [11].

To reduce the likeliness of its manifestation, either the volume of the hernia sac’s content needs to be reduced, or the volume of the abdominal cavity needs to be increased [1]. The first can generally be achieved by resection of viscus or omentum, the latter by use of progressive pneumoperitoneum (PPP) [5‐7], surgical component separation (CS), or staged closure of the abdominal cavity [5]. All of these options are resource and time consuming and, as invasive measures, they bear the risk of additional morbidity and adverse outcomes for the patients.

Another option—to date hardly implemented in the management of large scrotal hernias—is preoperative injection of the abdominal wall’s lateral muscles with botulinum toxin A. Compared to the described alternatives, it is a clearly less-invasive and time-consuming alternative. Over time, it leads to a predominant increase of the abdominal cavity’s volume, whereas PPP naturally also temprarily increases the inguinal hernia sac’s volume [12].

A generally accepted method for the measurement of hernia sac and intra-abdominal cavity volumes for large inguinoscrotal hernias has not been presented to the best of our knowledge. Both Tanaka et al. [7] and Sabbagh et al. [13] focused on incisional hernias in their work and provided techniques for measurements of the respective volumes. For the preoperative work-up of this case, Tanaka’s method and the described modifications were chosen. Relevant studies focusing on the peculiarities of volume measurements in inguinoscrotal hernias are still lacking, but volume calculations appear mandatory for these patients and should be considered an inherent part the preoperative work-up.

The hernia classification EHS pL3 is documented in the original theatre report. Since scrotal hernias generally tend to be EHS L3, further classification is warranted in these cases: Trakarnsagna et al. [14] suggest a classification of three grades with the hernia sac reaching to the mid-inner thigh (grade 1), to the suprapatellar lines (grade 2), or to the superior border of the patellar bone (grade 3) in their publication. According to this proposed recommendation, the case we present would be described as grade 3. In view of the consensus paper published by 25 surgeons of the HerniaSurge group in 2023 [15], the hernia described in this manuscript could be graded as S3 (IR) despite a very low level of evidence and weak strength of recommendation.

The described case shows that botulinum toxin A can be a valuable component of the hernia surgeon’s toolbox—not only in ventral, but also in large scrotal hernias with loss of domain. In view of the low number of published cases, it must be assumed that only a few surgeons currently use the technique for the management of these scrotal hernias. The underlying reason might be either the relatively low number of truly giant inguinal hernias in countries with readily available medical botulinum toxin A or the fact that the correlation between a treatment of the abdominal wall’s lateral muscles and the actual scheduled procedure well away from them in the groin is not initially obvious and, therefore, frequently overlooked.

Thorough preoperative planning, careful patient prehabilitation, and preconditioning of the extended surgical field can help to avoid an intraoperative impossibility of hernia content reduction into the abdomen, the need for additional surgical emergency measures in order to make reduction possible, or even forced reduction, which is associated with acutely elevated intra-abdominal pressure and an increased risk of the manifestation of ACS.

Open anterior mesh-augmented repair was considered the default procedure for scrotal hernias in most cases and for the majority of surgeons [15] in 2023. Implant size should reflect the size of the hernia defect and must naturally be adapted to the patient’s anatomy. In hindsight, further mesh fixation in addition to the medially placed nonabsorbable suture could have been considered. The implant chosen for the procedure described proved sufficient for the hernia repair until the end of the patient’s life.

Excessive scrotal tissue may not require resection due to its ability to shrink. However, scrotal hematoma is not uncommon and secondary skin resection may be found necessary [15].

For the presented case, a definitive repair in one operation was aimed for in view of the patient’s multimorbid condition. In hindsight, local complications could not be avoided and might have warranted a less-invasive approach despite the large amount of residual scrotal skin after intraoperative reduction of the hernia.

Zuvela et al. [16] doubt the efficacy of Lichtenstein’s repair for very large inguinoscrotal hernias. The authors present a case series with a median hernia defect size of 10 cm and including absurdly gigantic hernia sacs. For these very large hernias, favorable results could be achieved with preperitoneal repair techniques with or without very extensive additional surgical measures. While it appears next to impossible to achieve sufficient coverage of these giant defects with Lichtenstein’s technique, the procedure has proven suitable for smaller defects like the one presented in the current case.

The chosen treatment for this patient proved sufficient for the rest of his life and outlines the multiple difficulties potentially encountered in the management of large scrotal hernias. Due to the ongoing lack of robust available evidence with regard to best practice for the management of the affected patients, additional research remains important to achieve the best possible results. A carefully tailored approach remains a cornerstone of the affected patients’ successful treatment. Recent publications appear to support this fact.

Even though the small number of published cases makes further evaluation of the technique for giant scrotal hernias necessary, the presented case confirms the facilitated repair after BTA infiltration.

A multi-year postoperative follow-up according to the Herniamed register’s standards would clearly have been desirable. However, the patient’s demise for causes unrelated to the surgical procedure once again shows the usually associated extensive comorbidity profile and highlights the significance of meticulous preoperative planning of this not only surgically demanding cohort [17].

To the best of our knowledge, we describe one of very few cases of the successful use of botulinum toxin A for the management of giant scrotal hernias with loss of domain with a systematic preoperative work-up, a standardized surgical approach, and scheduled follow-up.

Despite best efforts and meticulous planning, certain limitations were found for this work: firstly, it cannot generally be ruled out that other therapeutic procedures would also have allowed for successful reduction of the hernia sac’s content into the abdominal cavity. On the other hand, and opposed to the situation in ventral hernias, there is no generally accepted method for calculating loss of domain from radiological images for inguinal hernias. Tanaka’s method and principle were applied, since they represent a well-established way of calculating loss of domain for ventral hernias and also for want of other, or better, reproducible options. In this case, however, the loss of domain was already clearly visible upon clinical examination.

Finally, the presence of a concomitant hydrocele makes the calculation even more complex, because this part of the extra-abdominal volume will be drained intraoperatively and does, therefore, not require reduction into the abdominal cavity. We compensated for these facts by deducting the fluid’s volume from the scrotal content and by axial correction of the CT scans prior to calculation.