A helping clamp for thoracoscopic plication of eventration of the diaphragm.

BACKGROUND AND AIM: It is difficult to suture an extremely thin and billowed up congenital eventration of the diaphragm thoracoscopically, without insufflation.
MATERIALS AND METHODS: The authors describe their technique using an intestinal clamp to control the redundant tissue and a feeding tube as a flexible knot pusher, to perform the thoracoscopic plication without risking hypercapnia.
RESULTS: A satisfactory result was obtained in all the four children.
CONCLUSION: This is a useful adjunctive for thoracoscopic plication of diaphragmatic eventration.

INTRODUCTION

In congenital eventration of the diaphragm, thoracoscopic plication provides an earlier and more complete return of function than a repair by open thoracotomy. However, thoracoscopy brings a few problems of its own. Insufflation with carbon dioxide (CO2) can cause severe hypercapnia during the procedure. If insufflation is stopped, the thin membrane billows up and makes it hard to plicate. The lateral-most part of the diaphragm is difficult to suture with the rigid instruments and ports.

MATERIALS AND METHODS

Technique

The child was positioned in the right lateral decubitus position with the head end of the table lowered. The (optical) port of 5 mm was placed in the fourth intercostal space in the mid-axillary line. Carbon dioxide at 4 cm water pressure was used to drop the lung. The two instrument ports, (3 mm in the infants and 5 mm in toddlers) were placed at the same transverse level, one in the anterior axillary line and one in the posterior axillary line. An additional incision, 2 to 3 cm long, was made through an intercostal space just above the lateral costophrenic recess. Insufflation was then discontinued. A curved intestinal clamp was passed through the wound, the blades were held close without clamping, the redundant diaphragm was drawn up between the blades, and the instrument was then clamped. This presented two pleats and a central bulk of redundant tissue for easy plication, with a single row of interrupted non-absorbable sutures using 2/0 Ethibond. The two lateral-most sutures were placed and tied through the thoracostomy, using conventional instruments [Figure 1]. For the rest of the suturing, the needle end of the suture was passed through the thoracostomy, the bites taken thoracoscopically, and the needle handed back outside for extracorporeal knotting. After creating a Melzer knot, the needle was passed through the tip of an 8F feeding tube. The tube then served as a flexible knot pusher to bed down the knot within the chest. At the end of the plication, the clamp was removed. The cut muscle edges in the mini-thoracotomy were approximated, leaving an 8F infant feeding tube connected to urobag to drain reactionary fluid. The port wounds were closed. The intercostal tube was removed the next day morning. The hemi-diaphragm appeared well flattened on the postoperative chest radiograph.

Figure 1

Schematic diagram on the relationship of the clamp and ports for left diaphragm plication

RESULTS

Four children (three boys, one girl) aged six days, four, ten, and twenty-four months, who suffered from recurrent respiratory infections since birth, underwent this procedure. There were three left and one right-sided eventration. The six-day-old child had respiratory distress since birth, with early onset pneumonia, and was on ventilator therapy. She could be extubated six days after the procedure. The postoperative recovery was uneventful with a satisfactory clinical result and chest radiograph in all the cases.

DISCUSSION

Several variations in the technique of thoracoscopic plication of diaphragmatic eventration are possible and have been described. In the first report of thoracoscopic plication in literature, for control of the diaphragm, Mouroux et al.,[1] used insufflation and a head up position, to keep the diaphragm down. Van Smith, Jacobs, and Burke, who published the first report of video-assisted thoracoscopy (VATS) on a baby on a ventilator, with phrenic nerve injury, used a 2 cm incision for lung retraction.[2] In 2003, Abraham from Kochi[3] and Hines from North Carolina[4] independently reported thoracoscopic plications in children. Abraham used a fan retractor to press the diaphragm down and used a single layer of interrupted silk sutures. Hines used a thin vascular clamp to draw out the peak of the eventration, under run it with sutures, and then suture the peaked cap to the lateral costophrenic recess. Sato et al.,[5] reported thoracoscopic plication in the lateral decubitus position with a block under the chest to open up the rib cage.

We believe that nuances of these techniques[67] can be tailored to the particular characteristics of the child with eventration. Lung handling is readily avoided by using the lateral decubitus and minimal head down tilt, without the need for single lung ventilation. Although carbon dioxide insufflation is excellent to get the diaphragm down at the start of the procedure, in the typical billowing type of congenital eventration, the intestinal clamp serves both as a retractor and tension adjuster in plicating the diaphragm, with a single row of sutures. A mini-thoracotomy allows the comfortable placing of the lateral-most diaphragmatic sutures as well as extracorporeal knotting of the interrupted sutures. Our innovative use of the feeding tube as a flexible knot pusher through the mini-thoracotomy allows bedding of the knot far into the chest and also saves suture material. Stopping carbon dioxide insufflation early gives a normal end-tidal CO2 throughout the surgery and in our series, allowed prompt extubation, except for the baby already on a ventilator. We have felt it appropriate to keep an 8F infant feeding tube as an intercostal drain to remove the small quantity of reactionary fluid, in the early hours after surgery.

Our innovations using an intestinal clamp to gather, retract, and tension the membranous diaphragm and use of the feeding tube as a flexible knot pusher for extracorporeal knotting are especially suited for the plication of thinned out congenital eventrations in children.