Laparoscopic pyloromyotomy

Laparoscopic Pyloromyotomy By Earl C. Downey, Jr Orange, California Extramucosal pyloromyotomy is a method with predictable morbidity and outcome for the cure of infantile hypertrophic pyloric stenosis. The method created by Ramstedt is successfully performed using a laparoscopic approach. Preliminary reports, including 266 cases treated by laparoscopic pyloromyotomy (LP), suggest that morbidity is comparable to that of open approaches. Advantages of LP include superior cosmetic result and no reported wound infections to date. For the experienced laparoscopic surgeon, LP is an precise and efficient technique, and the preferred method for the management of infantile hypertrophic pyloric stenosis. Copyright ~ 1998 by W.B. Saunders Company

HE ADOPTION of the te~hnique of pyloro.myotomy described by Ramstedt in 1911 resulted In a complete reversal of prior, unsuccessful, management of pyloric stenosis.1.2 Since this description, little has been added to the procedure because of its overwhelming success in relieving the gastric outlet obstruction caused by pyloric hypertrophy, accompanied by minimal morbidity and essentially no mortality. Because of the common occurrence of pyloric stenosis and low morbidity of Ramstedt's technique of myotomy, it has been logical to apply minimally invasive surgery (MIS) techniques as an alternative access for this procedure. In doing this, the concept of Ramstedt has not changed, but the I1]ethod and instrumentation required to gain exposure and perform . myotomy are different. 3 Herein we describe the techniques commonly used to perform pyloromyotomy using MIS and review the results of the studies that have tested laparoscopic pyloromyotomy (LP).

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PREOPERATIVE CARE There are no features of preoperative management unique to LP. The diagnosis is best established by physical examination in the majority of cases. A preoperative nasogastric tube is used routinely and left in place until the operation is completed. Nasogastric decompression increases the accuracy of physical examination and reduces the chance of vomiting and aspiration. It also reduces the possibility of injury from distension during port placement. The con equences of loss of volume hydrochloric acid are corrected with rehydration and electrolyte replacement before the operation is undertaken.

From Children :r Surgical Associates, Orange, CA. Address reprint requests 10 Earl C. Downey, .l!; MD, 1140 W Laveta Ave, Suite 540, Orange CA 92668. Copy right to 1998 by W.B. Saunders Compan.y 1055 -8586/98/0704-0004$08.00/0 220

TECHNIQUE OF LAPAROSCOPIC PYLOROMYOTOMY The technique detailed herein is patterned after that described by Tan et a1. 4- 8 The specialty instruments are listed in Table 1. After general anesthesia is induced, the patient is placed in the supine position at 90° to the anesthesiologist (Fig 1). The video monitor is placed at the head, and the surgeon stands at the feet. The bladder is evacuated with a Crede maneuver. The access sites are injected with local anesthesia with ~pinephrine, which is used to reduce skin bleeding. Capnoperitoneum is established with a Veress needle and a 5-mm (or smaller) port inserted through the umbilical site (Fig 1). Pressures are maintained at 8 to 10 mm Hg. Once the camera is placed, two stab incisions are made with a no. 1I blade to accommodate the operating instruments. The right-upperquadrant (RUQ) incision is placed just above the level of the liver edge so that the inserted instrument frequent ly restrains the liver edge. If the left-upper-quadrant (LUQ) incision is made too low, the incision on the pylorus can be more difftcult. An atraumatic grasper is placed through the RUQ site and used to fix the duodenum. In general, this is done only once because repetitive grasping of the duodenum is traumatic and is a potential source of technical error. A retractable arthrotomy knife with a 2-mm "banana" blade (3-M Center, St Paul, MN) is inserted through the LUQ site. The antrum is inverted toward the pylorus with the sheath of the knife (Fig 2) . This assists in estimating the proximal extent of the myotomy by showing the extent of induration from the muscle hypertrophy.9 The next critical maneuver is a firm incision in the pyloric muscle (Fig 3). Thi incision must be deep enough to allow insertion of the spreader blades. Failure to make this incision deep enough will require the operator to make another (or more) attempt to incise the pylorus enough. Use of the knife to deepen the incision can result in "railroad tracking" of the pylorus and a difficult myotomy. If an inadequate incision is made, a blunt-tipped instrument should be used, such as the sheath of the knife, the tip of the opened spreader. or a spatula as described by Alain et al,lo,11 to complete the incision. After the muscle is incised, the Hoc Tan spreader (Karl Storz Endoscopy-America, Culver City, CA) is placed into the myotomy at the midpoint of the incision (Fig 4). Gentle pressure is used laterally to open the muscle completely. Pushing the spreader toward the mucosa will result in a mucosal tear. Successful myotomy (Fig 5) usually requires several gentle applications of the spreader. Seminars in Pediatric Surgery, Vol 7, No 4 (November), 1998: pp 220-224

LAPAROSCOPIC PYLOROMYOTOMY

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Table 1. Specialty Instruments Used for Laparoscopic Pyloromyotomy • One 5-mm (or smaller) access port for the lens, camera, and insufflator • • • • •

O-degree fiberoptic rod Retractable myotomy knife, 2 mm Hoc Tan pyloromyotomy spreader Atraumatic grasper for the duodenum, 5 mm or smaller Variable pressure and flow insufflator sufficient for babies

Attempts to rapidly accomplish this complete fracturing of the muscle can result in mucosal injury. The distal and proximal one fourth of the incision are avoided to reduce the chance of mucosal violation (Fig 6). The completeness of the myotomy is tested, by either compression of the ends of the myotomy (Fig 7) or instillation of air by the anesthesiologist through the nasogastric tube to produce bulging of the mucosa. After the myotomy, the instruments are withdrawn under direct vision and the capnoperitoneum is evacuated. The umbilical fascia is closed with fine absorbable sutures. The umbilical skin incision is not readily closed with skin tapes; it is closed with dennal sutures. The stab incisions are closed with skin tapes. The nasogastric tube is removed. Approximately 4 to 6 hours after recovery from anesthesia, graduated feedings are begun, similar to postoperative care for open pyloromyotomy (OP). Most patients are discharged 18 to 24 hours after the operation.

OTHER TECHNIQUES Alain et al first described LP in 1991.12 Their technique differs somewhat from the above procedure, which was adapted from that originally described by Tan et a1. 4-8 Like most investigators, Alain et a1 use port devices for each access site. They use a separate insufflation site and

Fig 1. Surgeon's view at operation. The baby is posltioned.per~e~­ dicular to the long axis of the operating room bed. The mOnitor IS In line with the operating field and at the baby's head. Arrows indicate positions of the access sites and the respective instruments that are used through them.

Fig 2. The antrum is inverted, with the sheath of the knife toward the pylorus, to help estimate the proximal extent of the hypertrophy and myQtomy.

arrange their access sites differently. Their positioning of the right-handed site in the epigastrium is directed at fracturing the muscle, with the spreader oriented perpendicular to the incision, as is done in OP using the Benson or other spreader. Ford et al l3 believed that positioning the spreader at this site (rather than more laterally) avoids placing the knife blade too low on the tumor and reduces the possibility of duodenal perforation and the need for multiple incisions. Alain et al use a spreader with small flanges at the tips to prevent sJipping during the myotomy. Hamada et al l4 performed this technique in two patients, with use of a fourth access port to stabilize the stomach during myotomy. Stability has not been a problem in my experience. Rothenburg's technique lS for LP uses a very different approach to fracturing the muscle. After the muscle is cut with the retractable knife, the incision is deepened with

Fig 3. The incision is made starting at the duodenal-pyloric junction and is carried well up onto the antrum. It is made deep enough to insert the tips of the spreader.

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EARL C. DOWNEY, JR

Fig 4. The hypertrophied muscle is fractured along the length of the incision by spreading laterally and gently. Note the serration on the outside of the Hoc Tan spreader. This reduces slippage when spreading, and is a unique feature of this spreader.

the blunt sheath of the knife, a Babcock cJamp is used to grasp the upper edge and the knife sheath is reinserted into the myotomy. The two edges are spread apart until the myotomy is completed. Thi s is confirmed by moving the two edges of the myotomy, as is done in OP. In an initi al seri es of 20 patients, thi s technique was used without inadequate myotomy or mucosal violation. AVOIDING PROBLEMS DURING LAPAROSCOPIC PYLOROMYOTOMY

Spreading at the duod enal end of the incision is unnecessary and could easily result in mucosal violation , as it does with OP (Fig 6). The temptation to spread at the duodenal end should be resisted. The lesser contribution of the duodenal -end hypertrophy to the obstruction is well known , and thu s manipul ating the duodenal end of the myotomy with an instrument ri sks perforation, without significant benefit in relieving the obstruction. Although Alain et allO believe the knife incision was

Fig 5. Completed myotomy. Mucosa bulges freely.

Fig 6. To minimize the risk of mucosal violation. the spreader is not placed in the proximal or distal 25% of the myotomy.

responsible for the ir mucosal violations, I have never experienced a mucosal violation with the initial incision. All the violations I have ex peri enced have occurred through improper use of the spreader, either by pushing

Fig 7. Sufficient myotomy and mucosal violation are tested by compressing the duodenal and antral ends toward each other. Free bulging of the mucosa is seen, without evidence of leakage.

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223

with the tips or by placing the spreader tips too close to either end of the incision and spreading. Bleeding usuall y is insignificant if the incision has been made cleanly, only once, and away from the anterior inferior gastroepiploic feeders. Cautery is not necessary if the incision is made in the proper location. If the incision on the pylorus is made too inferiorly, it is possible to injure one of the left gastroepiploic branches, which will obscure the field of vision significantly with brisk bleeding. A helpfu l maneuver is to roticulate the duodenal grasper one or two clicks anteriorly, or rotate the tip of the grasper toward the camera before making the incision. Th is appears to expose the avascular area and align the pylorus for incision optimally in most cases. Estimating the extent of the myotomy can be a problem with LP. The use of any MIS alters tactile sense sign ificantly. Whi le it is possible to feel the resistance to the blade during incision and somewhat to the spreader during fracturing of the muscle, the tacti le sense that allows one to assess the completeness of myotomy during OP is not present or is significantly diminished for LP. Loose prolapsing of the mucosa through the myotomy as well as loose movement of the edges of the myotomy suffice as criteria for completeness. This can be tested by compression of the duodenum and antrum toward one another (Fig 7). Visual inspection based on experience also can indicate that the hypertrophy has been divided and normal muscu laris encountered. The omentum is sticky and is easily prolapsed even through these small incisions un less care is taken to prevent prolapse or replace the omentum in the abdominal cavity. If trapped in the incision, an operation will be required to repair the hernia. Suture closure of the umbilical fascia is recommended. When problems are encountered during LP, whether potential or real, in most situations they should be dea lt with by conversion to the open technique. The decision to convert to OP should be strongly considered whenever a situation appears that challenges the experience and/or ability of the surgeon and jeopardizes the success of the operation . For most cases this is not necessary; however, there are some cases of hypertrophy in which the pylorus is bizaITely-shaped, ilTegular, or in which the hypertrophy extends far onto the antrum. In such situations, strong consideration should be given by the operator to open immediately rather than accept an inadequate operation, ' including insufficient myotomy, mucosal violation, or some other complication. W ith experience, these situations become rare.

Table 2. Series of Laparoscopic Pyloromyotomy No.of Patients

Study

Average Operating lim e (min)

No.of Perforalions

Inadeq uate Myotomy

Scorpio et al (1995)8

26

27

0

0

Najma ldin and Tan (1995)5 Greason et al (1995)6

37 11

29 25

0 0

0 1

A lain et al (1996)11 Rothenburg (1997)15 Ford et al (1997 )13

78 20 33

20 13 41

2

0

0 3

0 1

Greason et al (1997)7 Downey (present study)

10 51

19 20

0 3

0 0

266

25

8 (3%)

2 (.8%)

Total (%)

LITERATU RE RE VI EW

The results reported for initial, small series of Lp511,13, 15 have been encouraging and have demonstrated that LP can be accomplished technically, with outcome similar to tbat reported for OP, although the sma)) size of the LP series does not allow for statistical comparison (Table 2). The incidences of mucosal perforation (3.0%) and incomplete myotomy (0.8%) in this collection of 266 patients with LP are similar to those of larger series of OP performed by pediatric surgeons (average of 2.2% perforations and 1.1 % relapm'otomies for persistent py loric stenosis). 16-18 The length of operation is not excessive. Wound dehiscence, postoperative hernia, and evisceration are not common with OP in modern times and were not encountered in this collected LP series. Wound infection has been a persistent problem with OP, with an incidence of up to 20% in the above large series, but this was not found in the LP patients. One might expect that, with placement of the camera port close to the umbilicus, some infections would have OCCUlTed, but so far this is not been the case. Three LP series 8.9.l 3 have compared patients LP and OP patients. Some differences, in time to resumption of full feedings, incidence of vomiting, and length of operation, have been observed. Because of the need for Im-ger numbers to demonstrate rel iable statistical significance, these data are inconclusive, but it does appear that Ramstedt's procedure has functionally the same longterm outcome whether it is done open or Japaroscopically. This makes teleological sense inasmuch as the operation to correct obstruction owing to pyloric hypertrophy is in reality unchanged, but is done with the MIS techn ique. For the experienced Japaroscopic surgeon, LP is a simple, gratifying, efficient, and preferable technique for relieving infantile gastric obstruction secondary to pyloric hypertrophy.

REFERENCES 1. Benson CD: Infantile pyloric stenosis. Hi storical a pects and current surgical concept. . Prog Pedi atr Surg 1:63-88, 1.970 2. Mack HC: A hi story of hypertrophic pyloric stenosis and its treatment. Bull Hi stMed 12:465,595,666, 1942

3. Hingston G: Ramstead' pyloromyotomy- Wh at is the correct incision? N Z Med J 109:276-278, 1996 4. Tan HL, Najmaldin A: Laparoscopic pyloromotomy for infanti le hypertrophic pyloric stenosi s. Ped iatr Surg Int 8:376-378, 1993

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5. Naj maldin A. Tan HL: Earl y experi ence with laparoscopic pyloromyotomy for infantile hypertrophic pylori c stenosis. 1 Pedi atr Surg 30:37-38. 1995

6. Greason KL, Thompson WR, Downey EC, et al: Laparoscopic pyloromyotomy for in fa ntile hypertrophic pylori c stenosis: Report of II cases. 1 Pedi atr Surg 30: 1571 - 1574, 1995 7. Greason KL. Allshouse MJ , Thompson WR, et al: A prospecti ve randomi zed evaluation of laparoscopic versus open pyloromyotomy in the treatment of infantile hypertrophic pyloric stenosis. Pedi atr Endosurg Tnnov Techniq 1: 175- 179, 1997 8. Scorpi o Rl, Tan HL. Hutson 1M: Pyloromyotomy : A comparison between laparoscopic and open surgical tec hniques. J Laparoendo c Surg 5:8 1-8 1. 1995 9. Cook RCM: Gastric outlet obstructions. in Lister J, Trving 1M (eds): Neonatal Surgery (ed 3). London, Butterworth, 1990, p 4 12, fi g 28 .8 10. Alain J, Grousseau D. Terrier G: Extramu,cosal pyloromyotomy by laparoscopy. J Pedi atr Surg 26: 11 9 1-1192. 199 .1

EARL C. DOWNEY, JR

II . Alain lL, Grousseau D. Longis B, et al: Ex tramucosal pyloromyotomy by laparoscopy. J Laparoendosc Surg 6:4 1-44, 1996 (suppl 1) 12. Alain J, Grousseau D. Terri er G: Extramucosal pyloromyotomy by laparoscopy. 1 Pediatr Surg 26: 11 9 1- 1J92, 199 I 13. Ford WDA, Crameri lA , Holland AlA: The learning curve for laparoscopic pyloromyotomy. J Pedi atr Surg 32:552-554, 1997 14. Hamada Y, Tsuji M , Kogata M, et al: Surgical technique of laparoscopic pyloromyotomy for infantile hypertrophic pyloric stenosis. Jpn ] Surg 25 :754-756,1 995 15. Rothenburg SS: Laparoscopic pyloromyotomy: The slice and pull technique. Pedi atr Endosurg Tnnov Tech 1:39-41, 1997 16. Benson CD: Infantile hypertrophic pyloric stenosis, in Welch Kl , Randolph IG, Rav itch MM, et al (eds): Pedi atric Surgery (ed 4) . Chicago, LL, Yearbook Medica l, 1986, pp 8 11 -8 15 17. Scharli A, Sieber WK, Kiesewetter WB : Hypertrophic pylori c stenosis at the Children's Hospital of Pittsburg from 19 12 to 1967. 1 Pedi atr Surg 4: 108- 114, 1969 18. Gord on HE, Pollock WF, Norri s WI, et al: Hypertrophic pylori c stenosis-Ex peri ence with L,573 cases at the Los Angeles Children's Hospital. West 1 Surg 67:139- 146, 1959