A novel two-port single-site laparoscopic pyloromyotomy for infantile hypertrophic pyloric stenosis.

OBJECTIVE: The objective of the study is to explore a less invasive laparoscopic pyloromyotomy for treating infantile hypertrophic pyloric stenosis. PATIENTS AND METHODS: A series of 154 cases from January 2014 to January 2020 were retrospectively analysed. Seventy patients were treated with the method of transumbilical single-site laparoscopic pyloromyotomy (SSLP), and 84 patients were treated with two-site laparoscopic pyloromyotomy. There was no difference in the body weight, sex ratio or age between the two groups. The operation time, blood loss, post-operative feeding time and complications between the two groups were compared.
RESULTS: The novel single-site method had better cosmetic effect than the two-site approach. There was no difference in the operation time, blood loss, post-operative feeding time or complications between the two groups.
CONCLUSION: The novel SSLP method requires only two incisions through the umbilicus to complete the procedure, with barely visible scars and similar surgical complications to that of the two-site approach; thus, the novel method is worth promoting.

INTRODUCTION

Infantile hypertrophic pyloric stenosis (IHPS) is a common disease in infants. It occurs in approximately three of every 1000 live births.[1] The typical presentation is projectile non-bilious vomiting occurring between 3 weeks and 3 months of age, which can also cause severe malnutrition, growth retardation and electrolyte imbalances. Pyloromyotomy is a good treatment modality for this disease. Laparoscopic pyloromyotomy was introduced in 1998.[2] Laparoscopy pyloromyotomy has advantages over open pyloromyotomy.[3] Muensterer et al. reported a single-incision laparoscopic pyloromyotomy in 2010,[4] and Yu et al. improved this approach by using a pyloric chisel.[5] However, placing three trocars through a small umbilicus can have the disadvantage of instruments conflicting, so there was only few paediatric surgery centre coverage of this technique. We attempted single-site laparoscopic pyloromyotomy (SSLP) with only two incisions. In this report, we describe the key feature of the procedure. We simplified the technique to avoid this shortcoming while reducing trauma. The outcomes of the procedure were excellent.

PATIENTS AND METHODS

Patients

We retrospectively analysed a series of children with IHPS treated by the same surgeon from January 2012 to January 2020. According to the surgical method, the patients were divided into two groups: novel SSLP and two-site laparoscopic pyloromyotomy (TSLP) groups. The inclusion criteria were as follows: all infants diagnosed with IHPS and treated by the same surgeon from January 2014 to January 2020. The exclusion criteria were as follows: (1) patients with umbilical infections, (2) patients with poor cardiopulmonary function and those who could not tolerate pneumoperitoneum and (3) patients with other diseases who required surgical treatment at the same time. All children were given routine pre-operative fluid rehydration, electrolyte correction, gastric lavage, gastrointestinal decompression and other treatments. From January 2014 to February 2017, patients were included in the TSLP group. Although the scars that result from laparoscopic procedures are very small, some parents of the patients still required the child to accept ‘scarless surgery’. Therefore, from March 2017 to January 2020, patients were treated with SSLP. We obtained approval from the Xi’an Children’s Hospital’s Ethics Committee.

Surgical methods

Equipment and experimental conditions: An Olympus Visera Elite OTV-S190 (Produced by Olympus corporation, Janpan) laparoscope was used; the flow rate was 1–3 l/min and the gas pressure was 6–8 mmHg. The two procedures are described as follows: (1) SSLP group: A 0.5-cm transverse incision was made from the inside out at 3 o’clock position and a 5-mm trocar was placed for laparoscope; suture fixation was performed to establish pneumoperitoneum and the pneumoperitoneal pressure was 6–8 mmHg. Another incision was made at 10 o’clock position in the umbilical ring from the top left to the bottom right and a 5-mm trocar was placed [Figure 1a and b]. When surgical instruments were inserted through the second incision, the transverse colon was pushed down, and the body of the stomach was pulled up to the left to expose the pylorus. A small gauze, when necessary, was placed on the right side of the pylorus to separate the pylorus from the liver and gallbladder. The serous membrane and muscular layer of the pylorus were cut in the region without blood vessels [Figure 1c], and then, a pyloric separation forceps was used to separate the pyloric muscle so that the mucosa was extruded [Figure 1d]. When the pyloromyotomy was completed, the gauze was removed from the abdominal cavity after haemostasis. The abdominal trocar port fascia layer was sutured, and the skin was glued together with a bio-adhesive. (2) TSLP group: The method of placement of the observed trocar and laparoscopy is the same as that of SSLP and the second 5-mm trocar was placed in the right upper abdomen near the pylorus. The rest of the steps were the same as those described for SSLP.

Figure 1

(a) Schematic diagram of the operation. (b) The location of two 5-mm trocars in SSLP. (c) Pyloromyotomy performed by electrocautery in SSLP. (d) Separation of the pyloric muscle in SSLP. (e) There is a small scar on the right upper abdominal wall 3 years after TSLP. (f) The incision scars are not obvious only 2 months after SSLP. SSLP: Single-site laparoscopic pyloromyotomy, TSLP: Two-site laparoscopic pyloromyotomy

Six hours after the surgery, the patients were given water followed by milk. When the amount of feeding reached 100 ml/kg in 24 h, which was considered sufficient feeding, the patients were discharged from the hospital. The growth condition and incision were the focus 1 month after surgery [Figure 1f].

Statistical method

IBM Corp. Released 2010. IBM SPSS Statistics for Windows, Version 19.0. Armonk, NY: IBM Corp. USA was used for data processing, Student’s t-test or the Mann–Whitney U-test was used for comparison, and the sex ratio was assessed with Chi-square test. The incidence of complications was low. Fisher’s test was used. P < 0.05 was considered statistically significant.

RESULTS

A total of 163 cases were included in the present study. There were one patient with obvious infection and umbilical cord swelling, two patients with poor nutritional status who could not tolerate pneumoperitoneum and six patients with combined inguinal hernias and umbilical hernias that added to the operation time. Nine cases were excluded in total. Among the patients, 70 children were in the SSLP group: 61 males and 9 females, and 84 children in the TSLP group: 72 males and 12 females. There was no difference in age, weight or sex ratio between the two groups [Table 1]. All the 154 patients were successfully cured, and none of them underwent conversion to open pyloromyotomy during SSLP. In one case, the pylorus had a hook shape and could not be completely exposed, so another trocar was added to the upper abdominal wall for catching the pylorus to complete the pyloromyotomy. The operation times of the SSLP group and the TSLP group were 21.4 ± 8.2 and 20.1 ± 8.3 min, respectively. The time to achieve adequate feeding in the SSLP group was equal to that in the TSLP group. One infant who had undergone an umbilical incision for SSLP presented with subcutaneous emphysema that was alleviated 2 days after the operation. Post-operative infection occurred in one patient in each of the two groups. One case of incomplete incision was found in the SSLP group. One patient with mucosal perforation in the TSLP group underwent conversion to an open procedure. There was no difference between the two groups in terms of operation time or bleeding, complications, length of hospital stay or time to adequate feeding. All the TSLP patients had visible scars, while the SSLP patients had no obvious scars because the scars were hidden in the folds of the belly umbilicus [Table 2]. The patients were all symptom free, and their growth and development increased rapidly to normal levels. The incisional scars were hidden, while the patients after TSLP had scars on the right upper abdominal wall [Figure 1e and f].

Table 1

The baseline and operation condition of the two groups

	SSLP (n=70)	TSLP (n=84)	P
Operation time (min)	21.4±8.2	20.1±8.3	0.3274
Bleeding (ml)	1.8±1.17	1.8±1.3	0.773
Age (days)	42.6±20.7	47.75±23.9	0.1372
Weight (kg)	3.4±0.64	3.5±0.75	0.6238
Gender (male/female)	61/9	72/12	0.7976

SSLP: Single-site laparoscopic pyloromyotomy, TSLP: Two-site laparoscopic pyloromyotomy

Table 2

Comparison of complications and recovery of the two groups

	SLP (n=70)	TLP (n=84)	P
Incomplete incision	1	0	0.4545
Incision infection	1	1	1.0000
Change procedure	1	1	1.0000
Mucosa perforation	0	1	1.0000
Adequate feeding time (day)	1.8±0.4	1.85±0.64	0.5196

SLP: Single-laparoscopic pyloromyotomy, TLP: Two-laparoscopic pyloromyotomy

DISCUSSION

We successfully implemented a simplified SSLP through two holes. The SSLP procedure we reported did not extend the operative time or increase the number of surgical complications. We successfully completed SSLP with only two incisions, and the results were satisfactory. SSLP reduces the interference and inconvenience of the instruments by placing only two trocars with limited trauma. This method has one less incision than the usual method and has two cosmetic hidden scars. Although there are reports of endoscopic pyloromyotomy, which can be scarless, this technique is very demanding and difficult to promote on a large scale.[6]

At present, the mainstream methods of laparoscopic pyloromyotomy are as follows: a three-port operation,[78] a two-port laparoscopic pyloromyotomy[789] and a transumbilical three-port method or umbilical single-port laparoscopy pyloromyotomy.[41011] Although the use of 3-mm instruments without trocar has a good cosmetic effect, this procedure has the following disadvantages: first, this procedure needs three incisions, including a laparoscopic incision and two operative incisions; second, instrument conflict may easily happen; third, when haemostasis is needed, it is difficult to put the gauze to the operative field and it is inconvenient to replace the instruments. We can expose the pylorus and achieve electrotomy and haemostasis through the operating port. This method is more convenient than a three-port operation and reduces the trauma due to the use of only two incisions. Harmon reported a single-site laparoscopic technique, but a thread needs to be sutured through the abdominal wall. We believe this to be unnecessary. Agrawal et al. also reported a simplified technique,[12] but our approach is simpler.

This two-incision operation also reduces the chance of instrument collisions, but this has still not been reported for this technique. We attempt to summarise our experience as follows. The enlarged pylorus can be clearly palpated through the abdominal wall and massaged downwards to help expose the pyloric muscle. We put two trocars on both sides of the umbilicus to reach a distance of about 0.5–1.0 cm to avoid equipment conflict. The placement of gauze strips helps avoid accidental injury to the liver and gallbladder. It also helps fix the pylorus and prevent the pylorus from shrinking under the liver. It can also be used for compression haemostasis after incision. Cutting all the pyloric muscles with an electric knife at one time may damage the mucosa, so our recommendation is to cut only a little at a time. The thickness of the pyloric muscle shown on ultrasound may be referenced, but the depth of the incision is usually 1 mm less than the measured thickness. Once the muscles weaken, pyloric pliers can be used to softly divide the muscle. It is important to cut from the avascular area. Our experience suggests that the difficulty with separation is often caused by the inappropriate position of the incision. If the duodenal end of the pylorus is difficult to separate, a Y-shaped incision on the side of the duodenal end can be used.[5] Pyloric separation forceps designed with anti-slip stripes on the outside is useful.[6] For children with an umbilical cord that is too small, the two incisions may be placed at 4 o’clock and 10 o’clock positions on the transumbilical ring to achieve a similar effect. The incision of the umbilicus needs to be carefully sutured to prevent the omental herniation.[13]

The limitation of this study is that it is a retrospective study. There is also a certain amount of experience needed to complete the procedure.

In summary, after mastering the traditional two-hole laparoscopic pyloromyotomy, it is feasible to complete SSLP with only two trocars. Compared with TSLP, this procedure also achieves the same effect and is even more aesthetic, without extending the operation time or increasing the number of complications.

CONCLUSION

The novel SSLP method requires only two incisions through the umbilicus to complete the procedure, with barely visible scars and similar surgical complications to that of the two_site approach. So it is worth promoting.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.