Keywords
reduction en masse - inguinal hernia - pediatrics - infant
Introduction
Inguinal hernia is one of the most common conditions encountered by pediatricians
and surgeons. Emergency cases often result from incarceration or intestinal obstruction.
Delaying treatment can lead to strangulation and ischemia of the intestine, sometimes
accompanied by peritonitis.[1] Typically, incarcerated inguinal hernias without signs of strangulation are managed
by manual reduction, which is generally effective and rarely leads to complications.
Reduction en masse is the reduction of the hernial sac into the preperitoneal space,
with a loop of bowel remaining trapped at the neck of the hernial sac.[2] This complication is rare following hernia reduction, usually associated with inguinal
hernias, and is characterized by the absence of a noticeable bulge in the groin.[3] The treating physician believes that successful reduction has been achieved and
discharges the patient. However, without prompt intervention, strangulation and intestinal
ischemia could develop.
We present a life-threatening case involving an infant with reduction en masse, necessitating
resection of the strangulated intestine. This represents the youngest reported case
of reduction en masse to date.
Case Report
The patient, a 2-month-old male infant, was born at 37 weeks of gestation with birth
weight of 2.5 kg and suffered from duodenal atresia. An open diamond-shaped duodenoduodenostomy
was performed on the second day of life. Additionally, the patient had a left inguinal
hernia and right undescended testis, with surgical intervention planned at the age
of 12 months. The patient presented with a nonreducible bulge in his left groin on
the night of the day before admission and showed irritability. The bulge gradually
became hard and swollen, and he cried when the bulge was touched. Ultrasonography
showed incarceration of intestine in the left inguinal hernia. Although manual reduction
was challenging, the hernia bulge became less noticeable without pain, medication,
and sedation. However, the left testis was positioned higher in the inguinal canal
([Fig. 1]). He was admitted, and we scheduled laparoscopic percutaneous extraperitoneal closure
for the next day. While hospitalized, the patient experienced abdominal distention
and several times of nonbilious vomiting after breastfeeding. The laparoscopy was
done the next day, and it revealed remarkably dilated intestines, serous ascites,
and an ischemic intestine in the left groin ([Fig. 1]). During the operation, the patient was head down positioned and we tried to retrieve
the ischemic intestine by pulling this by grasp forceps from inside and pushing the
bulge from outside but the ischemic intestine could not be retrieved ([Fig. 1]). A lower midline laparotomy was performed, revealing reduction en masse of the
left inguinal hernia with a strangulated ileum at its neck ([Fig. 1]). We made an incision at the neck of the hernia sac, followed by the resection of
the strangulated ileum, approximately 2 cm proximal to the ileocecal valve, and performed
an end-to-end anastomosis. The internal inguinal ring was secured with sutures from
the abdominal side, and the retractile left testis was fixed to the scrotum. The postoperative
period was uneventful, and the patient was discharged on postoperative day 15. However,
during follow-up, a recurrence of the left inguinal hernia was observed. We considered
laparoscopic percutaneous extraperitoneal closure might be technically difficult because
of adhesion around the internal inguinal ring. Therefore, the hernia was repaired
using the Mitchell Banks procedure, the hernia sac was isolated through the external
inguinal ring and ligated at the level of preperitoneal fat without opening inguinal
canal,[4] and orchiopexy for the right testis was also performed at the age of 13 months,
11 months after the operation for reduction en masse.
Fig. 1 (A) After manual reduction of the hernia, the hernia bulge was not appreciable, but
the left testis was raised to the proximal of the inguinal canal (arrow). (B) Laparoscopy revealed a remarkably dilated intestine, serous ascites, and ischemic
intestine at the left groin, which could not be retrieved to the surgical field. (C, D) A lower midline laparotomy was performed, and the hernia sac with a loop of bowel
remaining strangulated at the neck of the hernia sac in preperitoneal space was noted.
Incision of the thickened neck of the hernia sac, resection of the strangulated ileum,
approximately 2 cm before the ileocecal valve, and end-to-end anastomosis were performed.
Discussion
Reduction en masse was first reported by Luke in 1843,[5] with an incidence of 1 in 13,000 hernias.[6] Reduction en masse is likely to occur in conditions with a mobile hernia sac in
the inguinal canal, a narrow and fibrous neck of the hernia sac caused by repeated
manual reduction over time, and a mobile parietal peritoneum surrounding the deep
hernia ring, creating space for the hernia sac to become displaced while a loop of
bowel remains incarcerated.[3] In pediatrics, inguinal hernia rarely presents with a long-standing history, and
the hernia sac tends to adhere tightly to adjacent structures, such as the ductus
deferens and testicular vessels.[6] In fact, the incidence of reduction en masse in pediatric patients may be significantly
lower than 1 in 13,000 adult hernias, and only three pediatric cases of reduction
en masse have been previously reported ([Table 1]). Moreover, when reduction en masse occurs, a painful mass can sometimes be felt
in the proximal inguinal canal or above the inguinal ring, and older children could
complain of the symptom, but in younger children, especially in infants, as in our
case, the symptom can be ambiguous and diagnosis of reduction en masse could be difficult.[7] In our case, the patient showed irritability, but the hernia bulge became less noticeable,
and we misdiagnosed as hernia reduction had been successfully completed. The incarceration
was not released, and strangulation and peritonitis proceeded. It is important to
be aware of the disease for early diagnosis and prevention of such complications.
In our case, the mobility of the parietal peritoneum surrounding the deep hernia ring
and forceful reduction of the incarcerated hernia might have facilitated the displacement
of the hernia sac into the preperitoneal cavity. The elevation of the left testis
proximal to the inguinal canal following manual hernia reduction could be indicative
of reduction en masse in pediatric patients, where adjacent structures adhere to the
hernia sac and move with it. To ensure early detection and prevention of reduction
en masse, ultrasound scanning should be employed to rule out its presence. However,
in the report from the adult cases, ultrasound scanning offers high diagnostic accuracy
for reduction en masse, with 86% sensitivity and 77% specificity.[7]
Table 1
Reported cases of reduction en masse in pediatrics
|
Case
|
Author
|
Year
|
Age/sex
|
Type of hernia
|
Duration of hernia
|
Symptom
|
Day from reduction to operation (d)
|
Enterectomy
|
Procedure for hernia repair
|
The expected cause of reduction en masse
|
|
1
|
Olguner et al[3]
|
2000
|
13 y/M
|
Inguinal hernia (right)
|
15 d
|
Abdominal pain, vomiting, painful bulge at inguinal area
|
< 1
|
Not done
|
High ligation via inguinal incision
|
Lack of adherence of hernia sac to the neighboring structure (mobile hernia sac)
|
|
2
|
Bernie et al[2]
|
2012
|
7 y/M
|
Inguinal hernia (right)
|
N/A
|
Abdominal pain, vomiting, painful bulge at inguinal area
|
< 1
|
Not done
|
High ligation via inguinal incision
|
Lack of adherence of hernia sac to the neighboring structure (mobile hernia sac)
|
|
3
|
Yano et al[6]
|
2022
|
10 mo/F
|
Inguinal hernia (left)
|
High ligation via inguinal incision of bilateral inguinal hernia at 4 mo old
|
Vomiting, bulge at inguinal area
|
1
|
Not done
|
Laparoscopic percutaneous extraperitoneal closure and iliopubic tract repair
|
Lack of adherence of hernia sac to the neighboring structure by previous Potts procedure
(mobile hernia sac)
|
|
4
|
Our case
|
|
2 mo/M
|
Inguinal hernia (left)
|
2 mo
|
Vomiting, bulge at inguinal area
|
1
|
Done
|
High ligation via inguinal incision 11 mo after the operation for reduction en masse
|
Mobile parietal peritoneum surrounding deep hernia ring and forceful reduction of
incarcerated hernia
|
Abbreviation: N/A, not available.
Conclusion
When faced with the challenge of manually reducing an inguinal hernia, it is crucial
to perform the reduction gently. To ensure early detection and prevention of reduction
en masse, the absence of a hernia sac in the preperitoneal space containing a loop
of bowel should be confirmed by ultrasound. Overnight observation and close monitoring
may avoid a late presentation and timely interventions, even without an appreciable
bulge in the groin.
