Inguinal hernia is a common disease in pediatric patients with an estimated incidence of 1-5%[1] and hernia repair compromises of up to 15% of all operations in some pediatric centers[9]. Since the 1960s, Beijing Children’s Hospital has implemented several measures to meet the increasing demands of inguinal hernia patients in the outpatient department[10], which we attribute to heightened awareness of the disease in parents (Figure 1). The concept of day surgery has gradually gained international recognition and is now acknowledged as a practice which benefits patients with timely surgery. Reviewing our 12-year experience of 12190 patients between 2007 to 2019, we have summarized the characteristics and treatment results for pediatric ordinary and incarcerated inguinal hernia based on gender, andprovide our recommendations accordingly. To our knowledge, this study boasts the largest number of pediatric inguinal hernia participants.
Based on the results, we concluded that the ratio of male to female inguinal hernia was 4.8:1, which was higher than the reported 2.5:1[9]. Our study boasts of participant volume almost 10-12 times more than the reported articles[9] and we postulate that our result may be a better representation of the true morbidity. Additionally, the ratio of unilateral: bilateral and right: left: bilateral was 6.9:1 and 4.1:2.8:1 respectively, equal to other studies[9].
OIHR is the conventional surgical approach for the treatment of pediatric inguinal hernia and has been extensively adopted for years, whereas LIHR was introduced due to the rising demand for minimally invasive procedures and smaller incisions. Since its introduction, the choice between OIHR and LIHR has always been a controversial issue. Some studies have recommended LIHR for its aesthetical benefits and ability to repair CSH simultaneously. One distinct difference is that SPLEC, our method for LIHR, does not require laparoscopic suture skills[8]. Because proper suturing of the PPV is fundamental for successful hernia repair, the opportunity to sidestep laparoscopic suture therefore also potentially sidesteps re-surgery. Nonetheless, no study comparing OIHR and LIHR has been concerned with the differences between male and female pediatric patients. In this study, we analyzed the relevant data and addressed these differences.
Among males, OIHR had a shorter operative time for unilateral hernias (P < 0.01), and no difference for bilateral hernias (P = 0.25). At a median time of only 15 minutes, operative time for OIHR was about half that of LIHR, and this was also much shorter than other reported operative times[3]. This may be attributed to two factors. One, OIHR is a very common operation in our department. As such, the operative time was already appreciably short, due to both the continuous refinement of operative skills spanning nearly 60 years as well as the accompaniment of safe and effective anesthesia. Two, LIHR was only introduced in 2012, and the surgeons had less than 10 years of experience which resulted in a relatively longer operative time. There was no difference between OIHR and LIHR in male patients for ipsilateral recurrence (P = 0.66) but results showed that MCH was lower in LIHR (P < 0.01). Based on this result, we suggest that centers with vast experience in OIHR should consider OIHR for male patients as a shorter operative time would be more beneficial. Nonetheless, surgeons should be vigilant about the possibility of MCH.
Among female patients, results showed that OIHR had shorter operative time for both unilateral and bilateral hernia (P < 0.01, P = 0.01). When making comparisons with OIHR, other centers have reported a shorter LIHR operative time for both unilateral and bilateral hernia[11], and we agree that the operative time could be shorter with more experience. Although LIHR had a lower MCH rate than OIHR (P = 0.02), it also had a higher IRH rate (P = 0.02). Reviewing the 3 IRH female patients, we found that they all received surgery in 2013, which was only a year after the introduction of LIHR in our center. No other recurrence was found. We attribute the 3 IRH to unfamiliarity with LIHR and nonetheless recommend that female patients receive LIHR. It should be emphasized that the surgeon’s learning curve is substantial with LIHR[12]. When a surgeon is first introduced to the surgery, confirmation that ligation of the hernia sac is crucial to avoid potential IRH, regardless of additional operative time. Once surgeons become well acquainted with the surgical demands of LIHR, it’s use among female patients could be highly beneficial.
Firstly, compared to male patients, LIHR is safer for female patients. In male patients, frequency of thin and weak hernia sacs is higher, and there were even a number of complete inguinal hernia whereby the PPV was entirely open. These patients generally presented with a giant reversible inguinal mass along with an extremely thin hernia sac that was particularly prone to tear during surgery. We also witnessed several cases where due to the thin hernia sac, the vas deferens seemed to be inside the hernia. It was very difficult to integrally dissociate the thin hernia sac with OIHR, thus LIHR would not have been appropriate for this group of patients. Secondly, the spermatic cord and vas deferens, anatomical structures unique to males, is close to the posterior wall of the hernia sac, which increases the difficulty of dissection and ligation. Once injured, it could lead to severe complications. However, for female patients, the round ligament of the uterus is located at the posterior wall of the hernia sac, allowing for easier and safer dissection and ligation during LIHR[13]. Thirdly, female patients tend to be more concerned with aesthetics, thereby rendering LIHR as a preferred choice. Fourthly, LIHR provides the ability for exploration of uterus and ovaries, which is of great significance for future reproduction. Should any problems be identified, relevant surgery can also be given immediately. Fifthly, LHIR does not require extensive dissection of surrounding tissues and causes less disturbance to the normal anatomy[14]. Last but not least, the total incidence of bilateral hernia in female patients is higher. This study found that female patients presented with bilateral hernia 1.9 times more frequently than male patients. Contralateral exploration for PPV and simultaneous repair for the potential CSH can be easily carried out with LHIR, reducing potential emotional and financial burden for the family[15]. Additionally, since SPLEC does not require laparoscopic suturing of the PPV, when done accurately, it will also ensure a lower recurrence rate[8].This study therefore highly recommends LIHR for female patients.
Different from the ordinary hernia, results showed that operative time for incarcerated hernia was nearly 4 times longer, total hospital financial cost was 2.9 times higher, and hospitalization length was 4 times longer. When comparing the demographics data, we found that female patients had higher incidence, which was about 2.4 times greater than male patients. This can be explained by the fact that contents of incarceration for male patients only included the intestine or colon and thus bimanual reduction was sufficient. However for females, the ovary was the most common incarcerated hernia content besides the intestine. This could be related to the presence of a short round ligament[16]. Assessment of blood supply for an incarcerated ovary can sometimes be difficult and bimanual reduction tends to be more challenging, which explains why female patients have a higher chance of requiring emergent surgery. In addition, there were fewer female patients than male patients, which also contributed to the discrepancy in incidence between the two genders.
Another finding was that patients under the age of 1 year were more than 60 times more susceptible to incarcerated hernias than patients older than 1 year old. Explanation for this result can be attributed to the following 3 aspects. Firstly, PPV has a tendency of narrowing or obliterating as patients grow older[17], which in turn decreases the incidence of incarcerating. Secondly, patients under the age of 1 year old are unable to communicate either the telltale presence of an inguinal hernia or the pain and discomfort that might be associated with it. Inguinal hernia might only be noticed by caregivers when incarcerated. Thirdly, some parents become more aware of the possibility of a hernia incarcerating and can call for bimanual reduction before it happens. We hence conclude that more attention should be given to male patients under 1 year old in order to reduce the incidence of severe incarcerated hernias. Observation for incarcerated ovarian hernia in females should also be emphasized.
This study has some limitations. Firstly, this was a retrospective study and we did not randomize the selection of surgical repair, thereby causing selection bias,which might have indirectly caused a predisposition of success toward LIHR for females. Randomized selection for OIHR and LIHR would further indorse our findings.Secondly, we did not carry out an extensive postoperative long-term follow up, and potentially missed out on information regarding post-surgical complications such as hematoma and wound infection, as well as the issue oflong-term fertility function. However, should the PPV have been inadequately obliterated, it would have presented itself shortly after operation, during the post-operation follow up in our clinic, and thus would have been reflected in our study. Nonetheless, extensive follow-up would still be beneficial in providing additional reliability.