Morbidity After Neonatal Inguinal Herniotomy By Simon Phelps and Meena Agrawal

London, England

l Neonatal inguinal herniotomy is recognised by paediat- ric surgeons to be a potentially difficult procedure. This study reviewed the clinical, operative, and outcome details of 74 infants undergoing herniotomy at less than 44 weeks’ gestation with particular reference to the incidence of com- plications such as recurrent hernia and testicular atrophy. Follow-up information was obtained in 69 patients (9396, mean follow-up, 8.1 months). There were 8 recurrent hernias in 5 patients (2 bilateral recurrences, 1 second recurrence) giving an overall hernia recurrence rate of 8.6%. There was only 1 case of testicular atrophy (secondary to a wound infection and scrotal abscess). Despite the provision of a consultant-led service, the recurrence rate in neonates is much higher than that seen in the paediatric population as a whole. In light of commissioners’ current demands for quality standards and managed healthcare, it is important that outcomes in this high-risk group are defined separately from those of other patients undergoing inguinal herni- otomy. Copyright o 1997 by W.B. Saunders Company

INDEX WORDS: lnguinal hernia.

N

EONATAL INGUINAL HERNIOTOMY is known by paediatric surgeons to be a potentially difficult

procedure, but may not be recognised as such by others involved in providing or purchasing health care. Compli- cation rates often are not defined separately for such patients. The aim of this study was to determine the current complication rate after neonatal inguinal herni- otomy in a regional referral centre providing a consultant- led service.

MATERIALS AND METHODS

The clinical, operative, and outcome details of all infants undergoing inguinal hemiotomy at less than 44 weeks’ gestational age in our institution between January 1993 and December 1994 were reviewed with particular reference to the incidence of complications such as recurrent hernia and testicular atrophy. Follow-up information was sought from outreach clinic notes, referring hospitals, and by postal questionnaires from general practitioners.

RESULTS

Patients

During the period reviewed, 74 infants (71 boys (96%), 3 girls) aged under 44 weeks’ gestation at the time of surgery underwent 92 inguinal herniotomies. The mean gestational age was 32 weeks at birth (range, 24 to 41 weeks) and 39 weeks at operation (range, 31 to 44 weeks). The mean birth weight was 1.62 kg (range, 0.5 to 4.24 kg) and the mean weight at the time of surgery was 2.67 kg (range, 1.06 to 5.37 kg). Thirty-seven patients (50%) weighed less than 2.5 kg at operation (Fig 1).

Journal of Pediatric Surgery, Vol32, No 3 (March), 1997: pp 445-447

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1

N lo-

5-

o- 1-1.4 1.5-1.9 2-2.4 2.5-2.9 3-3.4 3.5-3.9 4-4.4 >4.5

Weight at operation (kg)

Fig 1. Distribution of weight at time of operation in 74 infants undergoing inguinal herniotomy at ~44 weeks gestational age.

Fifteen patients (20%) were oxygen dependent at the time of surgery (including 3 on ventilatory support) and 18 (24%) had bilateral hernias at presentation.

Of the 74 patients, 49 (66%) were elective referrals and 25 were referred as emergencies with “irreducible” hernias, 20 (80%) of which were successfully reduced at our Paediatric Surgery Unit. Only 5 hernias were truly irreducible, requiring emergency surgery (Table 1).

Operative Details

All the irreducible hernias were operated on by consul- tants, as were 75% of the reduced emergency referrals, and 80% of the elective group. All other procedures were supervised by consultants. The majority of infants (69 of 74; 93%) were also anaesthetised by consultant paediatric anaesthetists.

During surgery two of the five irreducible hernias reduced spontaneously under anaesthetic, and the remain- ing three contained viable bowel. Fifteen of the 71 male infants (21%) had an associated undescended testis, of whom 10 underwent simultaneous orchidopexy. A further 4 patients had other concurrent surgical procedures (anal dilatation, 2; umbilical herniotomy, 1; laparotomy for milk curd obstruction, 1).

From the Children S Hospital Lewisham, London, England. Presented at the 43rd Annual International Congress of the British

Association of Paediatric Surgeons, St Helier; Jersey, Channel Islands, July 16-19, 1996.

Address reprint requests to Simon Phelps, FRCS, Perinatal Research Fellow, Department of Paediatric Surgery, Children’s Hospital Lew- ishanz,. London SE13 6 LU, England.

Copyright 0 1997 by WB. Saunders Company 0022-3468/97/3203-0016$03.00/O

445

446

Table 1. Nature and Side of lnguinal Hernia in 74 Infants Aged Less

than 44 Weeks’ Gestation at the lime of Herniotomy

Unilateral

Bilateral Right Left All

Elective/reducible 18 17 14 49

Semi-urgent/reducible 0 11 9 20

Emergency/irreducible 0 3 2 5

Total 18(24%) 31(420/o) 25(34%) 74

Outcome

Follow-up information was obtained on 69 infants (94%) with 86 hernias. The mean follow-up was 8.1 months (range, 1 to 36 months). Overall, there were 8 recurrent hernias in 5 patients, 3 of whom were oxygen dependent at the time of initial surgery. Two of these infants had bilateral recurrences, and one subsequently had a unilateral second recurrence, giving a recurrence rate of 7.2% for patients and 8.6% for hemiotomies (Table 2). Contralateral hernias developed in 10 of 52 (19%) unilateral herniotomy patients at a mean of 30 days after the initial operation (range, 1 to 84 days).

In one infant a postoperative scrotal haematoma be- came infected with abscess formation and resulted in subsequent loss of the testis. There were no other instances of testicular atrophy or ascent, even in the five patients with irreducible hernias.

There was no perioperative mortality, although two infants died later of chronic lung disease.

DISCUSSION

Neonatal inguinal herniotomy is frequently a difficult procedure, particularly after incarceration of the hernia, even if it has been successfully reduced before surgery. The risk of damaging the tiny vas or testicular artery is high in infants, and is increased in small preterm babies who often have extremely large hernias.

Complication rates after inguinal hemiotomy are often calculated for the paediatric population as a whole, and these high-risk patients are rarely defined separately. Consequently the usual figure quoted for recurrent hernia is approximately 1% l,* and that for testicular atrophy between 0% and 1.5%.’

Two studies that have identified preterm and low birth weight infants separately have identified recurrence rates of 4%3 and 2.6%,4 respectively, but in the former only

PHELPS AND AGRAWAL

46% of patients were available for follow-up and in the latter no information on the weight at operation was given. Our series demonstrates a higher recurrence rate of 8.6% in similar patients, the majority of whom were below normal birth weight and less than 40 weeks’ gestation at the time of surgery.

The low incidence of testicular atrophy in our series (1.1%) compares favourably with reported rates of up to 22% in premature infants5 but is still higher than the mean reported incidence of 0.4% quoted for the general paediatric population,’ and highlights the importance of stratifying neonatal inguinal herniotomy separately.

Contralateral hernias are reported to arise in 16% to 29% of long-term studies and are a particular problem in premature infants. 6*7 Consequently, some investigators have advocated bilateral exploration in such patients, even if only one hernia is evident.3,8 It is our view that the higher complication rate after herniotomy in these pa- tients outweighs the risks of a second anaesthetic, and consequently we only undertake bilateral operations in infants with definite bilateral hernias.

The high incidences of recurrent hernia, testicular atrophy, and contralateral hernia development in infants who are small, pretemr, and often requiring ventilatory support at the time of surgery might suggest that it would be more appropriate to defer surgery until an adequate weight and age had been achieved. However, this view must be balanced against the frequency of incarceration in such hernias (up to 3 1% in preterm babieG), the risk of testicular ischaemia associated with each episode, and some anectodal evidence that oxygen dependency can be reduced by early repair.

Overall, the complication rate after inguinal hemi- otomy increases with prematurity, and with larger num- bers of increasingly small infants surviving, the number of complications may also be expected to rise. In these days of managed health care and demands for defined quality standards, it is important that neonatal inguinal hemiotomy is documented and evaluated separately from the same procedure in older children.

ACKNOWLEDGMENT

The authors thank Evelyn Dykes for assistance with manuscript preparation.

Table 2. Outcome for 69 Patients Who Underwent Neonatal lnguinal Herniotomy (EL = elective, SEM = semi-emergency/reducible, EM = emergency/irreducible)

Nature No. of No. of Recurrent Second Contralateral

of Hernia Patients Hernias Hernias Recurrence Hernia

EL unilateral 29 29 1 0 6 EL bilateral 17 34 4 1 -

SEM unilateral 18 18 2 0 4

EM unilateral 5 5 0 - 0

Total 69 86 7 (8.1%) 1 10 (19%)

COMPLICATIONS OF NEONATAL HERNIOTOMY 447

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