Present study was a prospective observational cohort study conducted on infants including neonates diagnosed and admitted with inguinal hernia. Inguinal and scrotal swellings are the common swellings encountered in infants and children. Most common is hernial swelling which is due to persistence of processus vaginalis which is present during intrauterine gestation for ease of descent of testis. The incidence of inguinal hernia (IH) in full term infants is 3.5 to 5.0%, whereas in premature and low birth weight (LBW) babies is 44 to 55% [1,2,3]. In our study, we found 22 (24.71%) of premature babies in GI and none in GII which were managed successfully.
Bronsther et al. have reported that, one-third of the patients in their series were of less than 6 months of age [4]. However, in our series, babies less than 6 months (GI) constituted around three times the infants in GII. Since ours is the only neonatal and paediatric referral centre in southern India; babies are referred to us quiet early.
Among GI, we had 70 (78.65%) males, 19 (21.3%) females with a ratio of 3.6:1, whereas in GII we had 24 (82.75%) males, 5 (17.24%) females, with a ratio of 4.8:1. Hence, the male predominance was seen in both the groups. Literature review reveals the ratio as, 6:1 by Poenarau et al., 7:1 by Grossfeld et al., 9:1 by Ravikumar et al. and 11.5:1 by Jadhav et al. [5,6,7]. Ours is the only series, which showed lower sex ratio despite lower socioeconomic status and the general public awareness.
Left-sided hernia predominated in GI 38 (42.66%), right side 31 (34.83%) with 18 (20.2%) were bilateral (synchronous) and 2 (2.24%) were metachronus hernias (Fig. 1a, b). In GII left were 14 (48.27%), right of 10 (34.48%) and 5 (17.24%) were bilateral without any case of metachronous hernia. Literature confirms the predominance of right-sided inguinal hernias, but our study revealed the just the opposite. The studies of Rowe et al., and Grosfeld et al., reported an incidence of 55–60% of the inguinal hernias on the right side, that of 25% on the left side and that of 15% bilaterally [2, 3, 8, 9] (Fig. 3).
Hoshino et al. [10] study confirms that babies operated for left-sided inguinal hernia repair had a 5.5-fold incidence of metachrnous hernia but surprisingly in our study we did not find its correlation [10]. We encountered only 2 (2.24%) cases of metachronous hernias in GI, and none in GII. Crankson et al. and Ballantyne et al. states that, because of low occurrence of metachronous hernia, contra lateral inguinal exploration is not justified [11, 12]. In our institute also, we generally do not follow the policy of the contra lateral groin exploration routinely.
Duration of symptoms in days in the both groups was found to be 18 ± 15 and 42.97 ± 56.28 in days, respectively, with a P value of < 0.0001, which was highly significant statistically. We found only one article where duration of symptoms correlated with our study by Kumar et al. [13, 14].
We had only three babies less than a month whose birth weight was above 2 kg, who were operated for hernia, and hence, they were monitored in neonatal intensive care unit (NICU) for a day or two post operatively and discharged uneventfully immediately after that. Very low birth weight premature infants with severe co morbidities are more likely to develop postoperative respiratory and cardiac events; hence a close observation in the NICU is advised for these babies.
22 (24.71%) babies were premature (28–33 weeks) in GI and none in GII, presenting during early gestation which were managed successfully.
Birth weight (kgs) in both the groups were 3 ± 3 and 2.63 ± 0.4, respectively, with a P value of > 0.05 which was not significant statistically. Crankson et al. and Kreiger et al. preferred to do hernitomy in premature babies just before their discharge from nicu, same protocol was applied in our babies [11, 13]. De Goede and Vaos et al. stated that lower weight at the time of surgery was not a contradiction of surgery [15, 16].
Weight at the time of surgery in both groups was 3.82 ± 1.12 and 8 ± 1.0, respectively, with a P value of < 0.0001 which was highly significant statistically which was correlated well with Yu-Li Lin et al. study [17]; in which they stated that no operation was postponed due to younger age or lower body weight, the same protocol was applied in our institute. Our babies had average of haemoglobin (HB) of 11 in both groups. Those who had HB of less than 10 were given haematinics and kept under close observation till surgery.
Two neonates in GI required blood transfusion due to exaggerated physiological anaemia to stabilise them for anaesthesia as well as for surgical challenge. In a study by Ozdemir et al., their babes had HB of 9 [18].
In GI, 81 (91%) had reducible inguinal hernia, 8 (8.9%) were irreducible, whereas in GII, 26 (89.65%) were reducible and 3 (10.34%) had irreducible inguinal hernia. All irreducible or incarcerated inguinal hernias at presentation were reduced by manual reduction of taxis manoeuvre by attending paediatric surgeon including the trainees at outpatient department as well as in the emergency room. Following reduction, they were planned for elective hernia repair once the baby is stabilised, during the same admission within 72 to 96 h. Zamakhshary et al. reported that risk of incarceration is highest in less than 2-year-old children and within a wait period of 14 days [19]. Palmer et al. and Smith et al. reported majority of the incarcerated hernias (83.3%) can be reduced by non operative manual reduction of taxis [20, 21]. None of our babies underwent emergency herniotomy and none of our babies had ischaemic/gangrenous intestinal segments during the procedure. None of our babies underwent laparoscopic hernia repair.
Rowe et al. reports incarceration more on right-sided inguinal hernias (17%) compared to left (7%) in their series; whereas, our result shows just the opposite; having left-sided hernia presenting with irreducibility 5 (62.5%) in GI and 2 (66%) in GII. Rowe et al., recommends elective surgery after a reduction, since it has a lower rate of complications as compared to an emergency surgery (1.7% vs. 22.1%) [6, 8, 9, 22]. In our institute also, we operate these babies as soon as diagnosed during the same admission electively.
Amongst the reducible hernias, we had 2 (2.46%) neonates with Amyand’s hernia containing normal appendix on right side type 1 as per Losonoff and Bassons classifications one in male and another one in a female neonate without any history suggestive of appendicitis, detected during the procedure; hence appendix was preserved. As per literature Amyand’s hernia usually presents acutely with scrotal or tender swelling in the groin region; but finding normal appendix without any symptoms is rare [22, 23]; same was witnessed in our case (Figs. 1g, 2).
We had 3 (3.7%) cases of hernial sac containing ovary amongst which, one had torted ovary; which could be detorsed and preserved in GI and one normal ovary (3.8%) in GII. Laing et al. stated that 15–20% of inguinal hernias in females do contain ovary and fallopian tubes [24]. Osifo et al. reported in their study that, out of 176 hernias, 145 (82.4%) were found to contain ovary and fallopian tube, which is a very high percentage in comparison with that obtained in the present study which showed only case 3.8% of inguinal hernias containing normal ovary [25].
We had 2 (2.24%) isolated syndromic cases, one was downs and another of cutis laxa syndrome in G1; none in GII. Two cases (2.24%) of syndromic (Edward's) associated with other anomalies in GI and one case (3.44%) of cutis laxa in GII (Table 2). 19 (21.34%) non syndromic babies having other conditions in GI and 9 (31%) in GII (Table 2) (Figs. 1c, 2).
Rescoria et al. stated that direct inguinal hernias are rare constitute 0.5% of all groin hernias [26]. We had only one case of direct inguinal hernia in GII with cutis laxa in which mesh repair was done primarily [27,28,29].
The Mitchell Bank`s operation was performed in three neonates by single consultant, where herniotomy was done without opening the external oblique aponeurosis. However, all other babies underwent standard Ferguson’s repair by all the consultants including the trainees in paediatric surgery (Fig. 1e, f). General anaesthesia using a combination of shorter acting agents such as sevoflurane and fentanyl, supplemented with caudal analgesics is a popular anaesthetic technique for infants. Babies did not receive any antibiotics pre- or post-operatively except few babies previously admitted for other commodities.
In our institute we attempt laparoscopic hernia repair in toddlers and children, but never in infants. Though the literature is abundant with laparoscopic hernia repair in children, it is limited in neonates as well as in infants at present moment, but however, it is exciting and worth attempting in near future.
Associated other surgeries conducted in 7 (7.8%) in GI like orchidopexy, congenital cataract surgery, Retinopathy, arthrotomy for septic arthitis, excision of duplicated bladder exstrophy. 5 babies (17.24%) in GII underwent other procedures like, cervical menigo myelocele repair, cleft palate repair, orchidopexy and ritual circumcision.
We had 2 neonates (2.24%) with undescended testis at superficial inguinal pouch where orchidopexies were done in GI and 2 babies (6.8%) in GII, during same anaesthesia. According to Witherington et al., a patent processus vaginalis with undescended testis is a clear indication for orchidopexy [30].
Ein et al. have reported a recurrence rate of 1.2%, whereas others report 3.8%. Recurrence rate in incarceration hernias is up to 3% [32]. We had only one case of 1.12% recurrence of hernia, in baby with duplicated exstrophy variant 4 months after the procedure, which can be explained due to difficult tissue planes and altered anatomy (Fig. 1d).
Ein had 1.2% wound infection rates [31]. None of our babies had surgical site infection; including any kind of surgical morbidity or mortality.
As per literature we found incidence of testicular loss or atrophy in 0–19% [30,31,32]. We had one baby (0.847%) with testicular loss, post herniotomy (Mitchell banks’ technique) done at day 2 of life in premature baby, noticed 3 months following the procedure. Turk et al. stated that Mitchells Banks’ technique is safer in older children [30, 32].
We had one morbidity in a baby with congenital cuts laxa syndrome having direct inguinal hernia where mesh repair was done, required longer time for recovery and discharge from the hospital (0.847%). Eventually, baby succumbed to other co existing illnesses 8 months following the procedure.
We did not have any mortality directly related to herniotomy procedure in our series.
Limitations of our study: routine ultrasonology and 2D echo cardiography were not done in all the babies pre operatively.
