Inguinal hernias account for a significant proportion of general surgical cases, particularly in aging populations.1 They result from an opening in the myofascial plane of the oblique and transversalis muscles, allowing intra-abdominal or extraperitoneal organs to protrude through the groin. These hernias are classified into indirect and direct, based on their anatomical location. Patients most commonly present with a visible bulge or pain in groin.2  The prevalence of inguinal hernia in India is estimated to range between 1.5 to 2 million, with a markedly higher incidence in men than in women. The etiology of inguinal hernias is multifactorial, involving both genetic and acquired risk factors.1 Increased intra-abdominal pressure resulting from obesity, chronic cough, heavy lifting, or persistent straining due to constipation also contributes to hernia development.2

While many cases present with unilateral defects, the concept of a contralateral bubonocele, a subtle pre-hernial condition, remains underexplored.3 A bubonocele often appears as a dimple in the inguinal region during laparoscopy and has the potential to progress into a fully developed hernia over time. Although preoperative ultrasonography (USG) is frequently utilized for assessing hernias, it may fail to detect subtle contralateral defects, which can only be identified intraoperatively.4

The identification and management of an occult contralateral defect during primary hernia repair could potentially prevent future symptoms, morbidity, and the need for an additional surgical intervention. Minimally invasive techniques provide an opportunity for surgeons to access and repair these latent defects with minimal modifications to the surgical approach.5 This cross sectional study aims to evaluate the occurrence of contralateral bubonocele in patients undergoing inguinal hernia repair and to determine the discrepancies between preoperative USG findings and intraoperative exploration, thereby enhancing our understanding of its clinical significance and potential implications for surgical decision-making.

The present study is a hospital-based cross sectional study conducted at Vishesh Jupiter Hospital, Indore, over a period of three years (2021–2024) after approval from institutional ethical committee.

The study included adult patients (≥18 years) undergoing elective inguinal hernia repair with preoperative ultrasound (USG) screening. Exclusion criteria comprised patients with recurrent and complicated hernia, those with a history of previous contralateral inguinal surgeries and with other combined procedures.

The sample size was determined using the formula:

N= 4PQ/d2

Where P represents the prevalence (11%)6,  Q  is calculated as (100 - P) (i.e., 89%), and d is the allowable error (considered as 5%). Substituting these values into the formula, the required sample size was calculated to be 157.

All patients underwent laparoscopic inguinal hernia repair, with intraoperative exploration of the contralateral side for the presence of a bubonocele, which was repaired if detected.

Data Collection and Statistical Analysis

Data for present study was collected using a predesigned semi-structured proforma. For statistical analysis, descriptive statistics were used to summarize demographic and procedural data. Statistical significance was analyzed using Chi-square and Z-test for comparison between two proportions with a p-value <0.05 considered significant.

Table-3: Laterality of Primary Hernia and Contralateral Bubonocele

Table-3: Among the 157 patients, the majority (57.3%) presented with a right-sided primary hernia. 62.5% of bubonoceles occurred on the right side.

Table-4: Classification of Hernia

Table-4 : Direct hernias were the predominant type, comprising 62.4% of all cases, whereas indirect hernias accounted for 37.6%. Among patients diagnosed with direct hernias 67.8% had bubonocele, while in patients with indirect hernias 32.2% had bubonocele.

Table-5: Risk factor association with and without bubonocele

Table-5 : Benign prostatic hyperplasia (BPH) was found to have a highly significant association (p=0.001).

Table-6: Comparison of USG and Intraoperative detection of bubonocele

Table-6: Preoperative USG detected bubonocele in only 22 out of 56 cases (39.3%), while intraoperative exploration identified all 56 cases (100%), yielding a highly significant P-value (<0.00001).

In our study, the majority of patients belonged to the 45-64 years age group (35.0%), while bubonocele was most frequently observed in the older 65-80 years group (35.7%). These findings align partially with Tiwary et al. (2020), who reported a mean age of 40.5 years, with a peak prevalence in the 51-60 years age range.⁷ Similarly Hammoud et al. (2023) reported peak after age of 70 years. Our study further emphasizes the predominance of inguinal hernias in males (95.5%), consistent with Hammoud et al., who noted that males account for approximately 90% of inguinal hernias. ²

Our study observed that the majority (57.3%) of hernias presented on the right side [Image-1(a,b)]. This is congruent with the findings of Tiwary et al. (2020),  where 73.3% of patients presented with right-sided hernias.⁷ Similarly, Jarrard et al. (2019) also reported a predominance of right-sided hernias (53.2%).⁵ This right-sided dominance is often attributed to the delayed closure of the processus vaginalis on the right, as highlighted by Hammoud et al. (2023).²

This finding contrasts with Tiwary et al. (2020), who found that 93.3% of cases were indirect hernias, with only 3.3% being direct.⁷ Epidemiological data from Hammoud et al. (2023) suggests that indirect hernias are indeed the most common type overall, particularly in younger patients. However, in older populations, direct hernias become more prevalent due to progressive weakening of the posterior wall of the inguinal canal. Given that our study population had a substantial proportion of older patients, this age-related shift may explain the predominance of direct hernias in our cohort.² Lee et al. (2017) further supports this observation, showing a higher rate of contralateral hernia (CIH) repairs in patients with direct hernias compared to indirect hernias (11.8% vs. 9.4%).⁸

Our study identified several significant risk factors for hernia development, including benign prostatic hyperplasia (BPH) (p=0.001), heavy lifting (p=0.018), obesity (p=0.007), constipation (p=0.035), and chronic cough (p=0.032). These findings closely align with the work of Hammoud et al. (2023), who emphasized increased intra-abdominal pressure due to obesity, chronic cough, heavy lifting, and straining as key contributors to hernia formation. Furthermore, Hammoud et al. highlighted a strong association between hernias and prostatic disease, consistent with our findings.² Lee et al. (2017) reported a higher risk of contralateral hernia repair in patients with comorbidities such as diabetes, renal disease, and prostate disease.⁸

A key finding from our study was the limited performance of preoperative ultrasonography (USG) [Image-3(a,b,c)] in detecting bubonocele, with only 39.3% of cases identified preoperatively, compared to 100% intraoperatively (p<0.00001). This diagnostic gap underscores the limitations of USG, which is highly operator-dependent, as noted by Hammoud et al. (2023).² Similarly Alabraba et al. (2014), reported that ultrasound has poor diagnostic performance in detecting occult groin hernias, with a positive predictive value (PPV) of 70%, implying a 30% chance of unnecessary groin exploration.⁴

While studies by Ismail et al. (2009)⁶ and Jarrard et al (2019)⁵ highlight that up to 50% of patients undergoing unilateral repair may harbor a contralateral occult hernia. This reinforces careful contralateral assessment during hernia repair, particularly in high-risk populations.

Our study emphasizes the diagnostic limitations of USG, reinforcing the need for meticulous intraoperative evaluation, a patient-centered risk-stratified approach to hernia diagnosis and management, with particular attention to modifiable risk factors and the potential benefits of laparoscopic bilateral assessment in selected patients.

Limitations

Being a single-center study, findings may not generalize to all settings. Reliance on surgeon-dependent intraoperative detection and operator-dependent ultrasound limits objectivity. The sample size, while sufficient for analysis, restricts detection of rarer associations. Additionally, the study lacked long-term follow-up to confirm whether identifying and repairing contralateral bubonoceles reduces future hernia occurrence, highlighting the need for further longitudinal research.

Informed Consent: Written informed consent was obtained from patients who participated in this study. 

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: The authors declared that this study has received no financial support.

1. Agarwal PK. Study of demographics, Clinical Profile and Risk factors of inguinal hernia: a Public Health Problem in Elderly males. Cureus. 2023 Apr 24;15(4).
2. Hammoud M, Gerken J. Inguinal hernia. InStatPearls [Internet] 2023 Aug 8. StatPearls Publishing.
3. Bochkarev V, Ringley C, Vitamvas M, Oleynikov D. Bilateral laparoscopic inguinal hernia repair in patients with occult contralateral inguinal defects. Surgical endoscopy. 2007 May;21:734-6.
4. Alabraba E, Psarelli E, Meakin K, Quinn M, Leung M, Hartley M, Howes N. The role of ultrasound in the management of patients with occult groin hernias. International Journal of Surgery. 2014 Sep 1;12(9):918-22.
5. Jarrard JA, Arroyo MR, Moore BT. Occult contralateral inguinal hernias: what is their true incidence and should they be repaired?. Surgical Endoscopy. 2019 Aug 15;33:2456-8.
6. Ismail M, Nair S, Garg P. Is prophylactic laparoscopic total extraperitoneal inguinal hernia repair on the contralateral side justified in less developed regions?: a comparative study of bilateral to unilateral repair. Journal of Laparoendoscopic & Advanced Surgical Techniques. 2010 Jul 1;20(6):533-6.
7. Tiwary SK, Kumar S, More R, Shankar V, Kumar S. A study of contralateral occult inguinal hernia in adult male patients undergoing total extraperitoneal herniorraphy. Journal of Family Medicine and Primary Care. 2020 Jun 1;9(6):2975-9.
8. Lee CH, Chiu YT, Cheng CF, Wu JC, Yin WY, Chen JH. Risk factors for contralateral inguinal hernia repair after unilateral inguinal hernia repair in male adult patients: analysis from a nationwide population based cohort study. BMC surgery. 2017 Dec;17:1-7.