Chapter 75 Laparoscopic Repair of Diaphragmatic Defects: Congenital Diaphragmatic Hernia (of Bochdalek) and Eventration Thane A. Blinman and Steven S. Rothenberg Introduction Minimally invasive surgery (MIS) is ideally suited to diagnosis and treatment of all forms of diaphragmatic defects. Obviously, the laparoscope affords accurate direct imaging of defects that have classically eluded accurate description by radiological techniques, and does so with minimal morbidity. But laparoscopy also allows repair of these defects with increased precision and vastly decreased pain compared to open techniques that rely on large incisions to give even marginal exposure (Hendrickson et al. 2003). Here we consider the repair of Bochdalek hernias and eventrations using minimally invasive surgical (MIS) techniques in children and newborns. The literature is littered with case reports of MIS repairs of Bochdalek hernias, but virtually all of the descriptions are of repairs in older children and adults (Harinath et al. 2002; Settembre et al. 2003; Willemse et al. 2003). Invariably, these patients had unrecognized congenital diaphragmatic hernias that were revealed during evaluation for other conditions. Alternatively, a few reports describe laparoscopy in the diagnosis or (more rarely) repair of traumatic diaphragmatic hernias (Marin-Blazquez et al. 2003; Matthews et al. 2003). Only one report describes experience with MIS repair of congenital diaphragmatic hernia (CDH) in the newborn, and here the only success came using a thoracoscopic approach (Arca et al. 2003). Nevertheless, CDH can be repaired using MIS techniques. Recently, our institution reported 15 successful repairs of CDH (12 Bochdalek and 3 Morgagni) by laparoscopy (Hendrickson et al. 2003). Twelve of these patients were infants, and recently we successfully repaired Bochdalek CDH (B-CDH) in two additional newborns. The techniques described focus primarily on B-CDH in neonates, but the methods are similar in older children and in patients with eventration. Preoperative Preparation Before Induction of General Anesthesia Babies with eventration are diagnosed by routine chest X-ray, and do not exhibit the pulmonary hypertension as seen in B-CDH. Eventration is distinguished from phrenic nerve injury by ultrasound or fluoroscopy. Babies with B-CDH are often diagnosed in utero by ultrasound (or rarely by magnetic resonance imaging), but occasionally an otherwise normal baby will exhibit subtle dyspnea and a chest film will reveal air-filled loops of bowel in the chest. Over 90% of B-CDH will occur on the left. Babies with CDH will exhibit varying degrees of pulmonary hypertension and associated physiologic derangements, with some experiencing almost no cardiopulmonary compromise, and others so ill as to require extracorporeal life support (ECLS). In general, dysfunctional physiology will appear within 12 h postnatally, after a relatively benign honeymoon, and attempting surgery during these fragile first hours has been shown to increase mortality. For this reason, immediate repair, regardless of method, has been abandoned in favor of preoperative stabilization. Babies are best repaired once FiO 2 requirement is below 50%, and positive end-expiratory pressure (PEEP) is less than 10 mmhg. Requiring pressors is not a contraindication for surgery; indeed, ongoing pressor requirement may signal a need for repair in order to restore the mediastinal structures to midline. No baby has been reported repaired by MIS while on ECLS. After Induction of General Anesthesia Epidural anesthesia is generally not used. Trocar sites are usually injected after the abdomen is insufflated so that ports are placed most advantageously. A Foley catheter is placed only if the overall physiologic condition warrants. All patients receive a dose of a first-generation cephalosporin unless they are already on antibiotics (many neonates will be treated with ampicillin and gentamicin for other reasons). All patients should have a sumping nasogastric tube inserted and placed to low continuous suction.
570 Diaphragm Fig. 75.1. Operating room setup. Reverse Trendelenburg positioning facilitates reduction of abdominal viscera out of the chest Positioning Patient Babies are positioned supine at the foot of the table (Fig. 1). The legs are gently frog-legged and all extremities are carefully padded with synthetic sheepskin. A small bump may be placed beneath the abdomen if desired, but too large a bump may make closure of the diaphragm more difficult. An arterial line and two working venous lines are placed. Gentle reverse Trendelenburg position facilitates reduction of bowel out of the chest. Crew, Monitors, and Equipment The surgeon stands at the foot of the bed. An assistant holds the camera from the surgeon s left. Another assistant may hold a retracting instrument from the surgeon s right, standing to the left of the table. Two monitors are used. If tower-based, they should be positioned on either side of the patient s head. If located on flexible booms as part of an integrated suite, one monitor should be suspended directly above the patient s chest. Another monitor can be positioned as needed for the assistant holding the camera, typically just to the left of the patient s head ( Fig. 75.1). Special Equipment No special energy applying systems are required. The use of Ligasure is optional. A collagen mesh should be at hand in case it is needed.
Chapter 75 Laparoscopic Repair of Diaphragmatic Defects: Congenital Diaphragmatic Hernia and Eventration 571 Technique Cannulae Cannula Method of insertion Diameter (mm) Device Position 1 Closed (Veress) 5 Camera Umbilicus 2 Closed 5 Needle driver, scissors, cautery Left lower quadrant 3 Closed 3 Curved dissector Right lower quadrant 4 Closed 3 Retractor, atraumatic grasper Right subcostal Procedure The following describes the method of repair of leftsided B-CDH, but the same technique is used for rare right-sided defects and for eventration. Trocar placements are shown in Fig. 75.2. A 5 cm trocar is placed into the umbilicus after inflating the abdomen to 8 10 cmh 2 0. Careful monitoring during pneumoperitoneum is essential, and the surgeon should be prepared to decrease the CO 2 pressure to as low as 5 cmh 2 0 (or to convert to an open technique) if cardiovascular compromise is encountered. To date, conversion has not been needed at our institution. Three other trocars are placed as shown. The left triangular hepatic ligament is divided sharply, and the left lobe of the liver is deflected caudally. (In cases where the left lobe is small or is already out of the way, taking down the ligament may make repair more difficult; the surgeon may elect to leave the liver in place.) For the entire case, the assistant provides exposure by maintaining gentle downward pressure on the liver and intestines. The surgeon uses non-crushing graspers to gently reduce the large and small intestine, carefully drawing the bowel all the way down to the pelvis as much as possible. Often, the spleen is in the chest as well, and this is reduced not by grabbing the spleen but by a combination of gentle blunt manipulation of the spleen and by folding the diaphragmatic rim under or over the spleen. If there is a sac, it is excised using scissors with sparse use of electrocautery. As with open repair, complete excision of the entire sac is crucial for a lasting repair. The sac is drawn out through one of the 5 cm trocars. The posterior rim of the diaphragm may be folded and hidden beneath loose areolar tissue. These attachments, and any adhesions to the splenic flexure of the colon, are divided sharply to fully reveal the posterior rim. Occasionally, some attachments still hold the left lobe of the liver over the medial portion of the diaphragm and these should also be divided with special care not to divide the phrenic vessels or to cut into the hepatic veins, any of which may be located more laterally than anticipated. Fig. 75.2. Schematic of port placement: port sizes (mm) are indicated. Port placement is very similar to that for laparoscopic Nissen fundoplasty. The left upper quadrant port is optional, but is often helpful to retract the bowel during repair Fig. 75.3. Intraoperative view of a left-sided CDH showing the muscular rim remaining after the hernia sac has been sharply excised
572 Diaphragm The left lobe of the liver should be placed directly against the repair. Directly positioning the liver prevents bowel from becoming caught above the liver, and may bolster the repair. Chest tubes and abdominal drains are not used. Immediate postoperative chest X-ray will reveal a large pneumothorax until the CO 2 is reabsorbed and the hypotrophic lung can expand to fill the space. No attempt should be made to evacuate the pneumothorax unless the patient later develops evidence of a pulmonary air leak (usually as a consequence of ventilator-induced volutrauma/barotrauma). The trocar sites are infiltrated with 0.25% bupivacaine and closed. Postoperative Care Fig. 75.4. Completed left-sided CDH repair: a series of simple interrupted 2-0 Ethibond sutures closes the defect In most cases, primary repair of the defect is possible. Several simple interrupted 2-0 Ethibond sutures are placed from medial to lateral and tied extracorporeally. Cocking the needle far back greatly facilitates placement of sutures into the upper leaflet. Care should be used to take bites just deeply enough to provide solid closure without diminishing the amount of tissue available to cover the gap ( Figs. 75.3, 75.4). Laterally, if there is no rim of diaphragmatic tissue, the anterior rim should be anchored to the ribs, avoiding the costal neurovascular bundle beneath each rib. Occasionally, there is not enough native tissue to close the defect. In this case, as with open repair, a piece of mesh is used to bridge the gap. Although Goretex mesh has traditionally been used in open repair, and provides adequate closure, it has disadvantages, chief among these being its propensity to act more as a foreign body than as a biological scaffold. Consequently, we favor Surgisis (Cook, Bloomington, IN) mesh, a collagen-based mesh that promotes ingrowth by fibroblasts thereby allowing more natural healing. A piece of mesh is cut to size extracorporeally, rolled tightly, and deployed into the abdomen by drawing it through a 5 cm port with a 3 cm instrument. It is then sutured in place using several interrupted 2-0 Ethibond sutures spaced approximately 5 mm apart. It is easier to work medial to lateral, beginning with the posterior leaflet. For eventration, the diaphragm is plicated using several interrupted 2-0 Ethibond sutures, closing the slack portion of the diaphragm horizontally as with a diaphragmatic hernia. Avoid incorporating the phrenic vessels into the closure. Patients invariably remain intubated immediately after repair and are weaned according to their individual physiology. Pain is controlled with ketorolac (0.5 mg/ kg intravenously every 8 h for six doses) and small doses of morphine. Patients can be fed when postoperative ileus has resolved. Many patients will have gastroesophageal reflux and will require metoclopramide and an H-2 blocker for months, and a few will eventually require fundoplasty. Results No prospective trials have been reported, but in our series of 17 patients there were no conversions to open technique. All patients had satisfactory repair and unremarkable postoperative courses. Laparoscopic repair has not been attempted in every patient with CDH, as early attempts have been confined to the most stable patients. As experience is accumulated, we have slowly expanded the number of patients in whom MIS is attempted. Discussion Laparoscopic repair of CDH offers a number of advantages compared to open repair. Open repair is typically accomplished through a large subcostal incision that is obviated by MIS repair. Requirements for pain medicine are vastly diminished, possibly shortening intubation time and postoperative ileus. Cosmesis is improved. Finally, reoperation (for example, to treat gastroesophageal reflux) is facilitated by diminished postoperative adhesions invariably seen after MIS compared to open procedures. The need for CO 2 pneumoperitoneum may present the major obstacle to accomplishing MIS repair of
Chapter 75 Laparoscopic Repair of Diaphragmatic Defects: Congenital Diaphragmatic Hernia and Eventration 573 CDH in patients with tenuous cardiopulmonary physiology. Still, low pressures allow adequate pneumoperitoneum for repair and minimize cardiopulmonary compromise. These considerations present no problem in eventration. One group has advocated a thoracic approach to repair of CDH (Arca et al. 2003). This approach could have some advantages. For example, it is likely that insufflation of the chest presents some advantage to reducing the organs from the chest. But this advantage vanishes as soon as the viscera no longer totally occlude the diaphragmatic defect and CO 2 pressures equalize. It is also possible that lower insufflation pressures could be used during the repair since the ribcage does not need to be elevated like the abdominal wall. Still, if insufflation incompletely reduces the viscera, the thoracic approach offers no advantage during manual reduction of intestines or spleen, but does leave those organs relatively inaccessible in case of a problem (like an enterotomy). Finally, the thoracic approach may offer a disadvantage during placement of sutures since it is more difficult to hold bowel away from the needle and to visualize safe placement of sutures. This problem does not appear during the abdominal approach. Technical refinements to both approaches will allow pediatric surgeons to choose the approach that seems most precise and gives the soundest repair. References Arca MJ, Barnhart DC, Lelli JL, et al (2003) Early experience with minimally invasive repair of congenital diaphragmatic hernias: results and lessons learned. J Pediatr Surg 38:1563 1568 Harinath G, Senapati PS, Politt MJ, et al (2002) Laparoscopic reduction of an acute gastric volvulus and repair of a hernia of Bochdalek. Surg Laparosc Endosc Percutan Tech 12:180 183 Hendrickson RJ, Rothenberg SS, Partrick DA (2003) Laparoscopic repair of congenital diaphragmatic hernia. Pediatr Endosurg Innov Tech 7:97 Marin-Blazquez AA, Candel MF, Parra PA, et al (2003) Morgagni hernia: repair with a mesh using laparoscopic surgery. Hernia 8:70 72 Matthews BD, Bui H, Harold KL, et al (2003) Laparoscopic repair of traumatic diaphragmatic injuries. Surg Endosc 17:254 258 Settembre A, Cuccurullo D, Pisaniello D, et al (2003) Laparoscopic repair of congenital diaphragmatic hernia with prosthesis: a case report. Hernia 7:52 54 Willemse P, Schutte PR, Plaisier PW (2003) Thoracoscopic repair of a Bochdalek hernia in an adult. Surg Endosc 17:162