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Gastrointestinal interventions—emphasis on children
Gastrointestinal Interventions—Emphasis on Children Bairbre L. Connolly
Although the fundamental principles of interventional and minimally invasive image-guided techniques are the same in children as in adults, nonetheless the spectrum of diseases, the pediatric approach, and the devices used differ significantly from those in adults. The following is a general overview of image-guided gastrointestinal interventions in children and neonates, with emphasis on those aspects peculiar to children. Many of the facets and tips have been learned the hard way over the years, in a busy pediatric practice. Although there are several potential ways to do some of these procedures, the description below reflects our practice and experience. In general terms, minimizing radiation dose is a significant responsibility for the pediatric interventionalist. Reducing the number of exposures, reliance on last image hold, low-dose pulse fluoroscopy, and tight coning are all important. Protection for the radiologist is equally important, but sometimes difficult to achieve, given the small size of many of the patients. © 2003 Elsevier Inc. All rights reserved.
Gastrostomy and Gastrojejunostomy Tubes For infants unable to feed by mouth due to congenital or acquired abnormalities, gastrostomy (G) and gastrojejunostomy (GJ) tubes are life-preserving devices that enable adequate nutrition to be sustained. As distinct from adults in whom feeding tubes are frequently a palliative measure, most children with G and GJ tubes live for a significant length of time; the cumulative effect on society and health care is therefore significant. There are many ways to place feeding tubes, e.g., surgical, PEG, “push–pull”1-3; however, the technique described below is the retrograde radiological method.4 While its advantages lie in its simplicity of placement, suitable for even the most medically fragile of children, its low morbidity, and its low complication rate, these must be balanced against the ease at which it may become accidentally dislodged.5-9
Indications and Contraindications The indications for a G-tube include those patients with oromotor dysfunction, inability to feed or swallow safely, or inability to achieve adequate intake for their caloric needs. The majority of those referred suffer from neurological disorders, e.g., cerebral palsy, syndromic abnormalities, with associated failure to thrive. Children with high caloric needs include those with chronic renal or cardiac failure (to promote growth before surgery or organ transplant) and cystic fibrosis.10-12 Patients with oncological disorders with predictable weight loss, mucositis,
From the Image Guided Therapy Centre, Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, Toronto M5G 1X8, Canada. © 2003 Elsevier Inc. All rights reserved. 1089-2516/03/0604-0006$30.00/0 doi:10.1053/j.tvir.2003.10.001
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or odynophagia are also potential candidates.13 Those with specific metabolic demands (e.g., glycogen storage diseases or ketogenic diets) and those requiring specific medications (e.g., HIV) account for a minority of patients. The indications for a GJ tube include all of the above in those patients with severe gastroesophageal reflux, rendering them at risk for aspiration of gastric contents if fed through a G tube.14 In our institution, children rarely undergo fundoplication, unless they have failed a period of nutrition through a GJ tube. A trial of G feeds is often attempted initially because of maintenance issues with GJ tubes.14 Conversion from a G to a GJ tube is usually easy, but does depend on the angle of the tract.15 A minority of children require a venting G tube and a feeding GJ tube, e.g., Superior mesenteric artery syndrome. There are relatively few contraindications to tube placement; however, they include uncorrectable coagulopathy, occasionally severe visceromegaly or unfavorable anatomy that precludes safe access, and lack of parental consent.
Decision The decision to proceed with a G or GJ tube requires careful consideration and a multidisciplinary integrated approach to care.16 It requires access to the necessary support structure (educator, dietician, occupational therapists, pediatrician, etc.) for ongoing care for the children and their tube maintenance issues, not just the interventional team. Parents must be actively involved in this decision and “buy in” to the decision to proceed, as many are initially reluctant to take this step.10
Consent Informed consent is obtained, outlining the risks including bleeding, infection leading to peritonitis, damage to any other adjacent organ, inability to obtain a safe access route, local site problems, as well as on-going tube maintenance issues.16 The risks of sedation or general anesthetic must also be included.
Sedation A radiologically placed retrograde G or GJ tube can be placed under local anesthetic alone, sedation and local anesthetic, or general anesthetic plus local anesthetic, depending on what is the safest for the patient’s overall medical condition. The following are the regimens and doses we use: Chloral hydrate, 50 to 100 mg/Kg for neonates and infants ⬍6 months or ⬍10 kg; a combination of Nembutal 3 mg/Kg and Demerol 1 mg/Kg for children 10 to 30 kg; a combination of Diazemul 0.1 mg/Kg and Demerol 1 mg/Kg for older children ⬎30 kg. With the latter two combinations, we use the option of giving a second dose if needed. The local anesthetic used is 1% lidocaine, 0.5 ml/Kg, or Marcaine 0.25%, 1 mL/Kg. Many of the children are medically so fragile that local anesthetic alone represents the safest method by which to place a G tube. Pacifiers, distraction meth-
Techniques in Vascular and Interventional Radiology, Vol 6, No 4 (December), 2003: pp 182-191
Fig 1. (A) Lateral fluoroscopy showing an air-filled stomach with NG tube in situ, and barium with air in the colon. A safe access route is seen, above the transverse colon, indicated by metal instrument. (B) Lateral fluoroscopy showing an air-filled stomach with needle entering the stomach above the colon. Contrast drips freely from the needle into the stomach cavity. (C) AP view of the same case showing the needle after puncture, and contrast puddling around the NG tube.
ods, videos, music, etc. are all useful adjunctive tools, depending on the child’s neurological ability.
fill. If the patient has a small silastic feeding tube in place, it is prudent to exchange it for a regular NG tube for efficient gastric drainage postprocedure.
Technique Antibiotics are given before the procedure (Cephazolin 40 mg/ Kg, to a maximum of 2 g). This is also used for children who require cardiac prophylaxis. The lower limits of the liver and spleen are mapped with ultrasound (e.g., 10 MHz linear probe) using an indelible marker on the skin. The position of the lower left costal margin is also marked on the skin before inflation of the stomach with air, as the costal margin in small infants is not prominent, and proximity to it may be overlooked when placing the tube. Ideally one should leave at least two finger breadths between the ribs and the chosen G tube site, as the costal margin descends as the child grows. It may therefore with time encroach on the G tube site and cause severe irritation. Dilute barium (4:1) is administered by rectum by the hangingbag technique (through a 16-22 Fr. Foley catheter with the balloon inflated) to outline the transverse colon. In children with Hirschsprung’s disease water-soluble contrast should be used, rather than barium. Glucagon is administered intravenously; dosage is usually empirically based on patient’s size rather than per kilogram calculation, although such doses are available (rule of thumb: 0.2 mg for the neonate, 0.3 mg for the infant and toddler, 0.4 mg for young child, and 0.5 for the older child). Following the administration of glucagon, air is inflated into the stomach via a nasogastric tube under fluoroscopic control, ensuring that the tip of the NG is within the stomach and not through the pylorus, and that the small bowel does not GASTROINTESTINAL INTERVENTIONS—EMPHASIS ON CHILDREN
Choice of Site Once the stomach is moderately tense with air, a site is chosen below liver, spleen, and left costal margin, and above transverse colon. The ideal location is lateral to the rectus abdominus muscle. If this is not possible, then a midline G tube is next considered; least ideal is one through the rectus muscle. The latter may be acceptable in those children who are hypotonic and severely impaired. The potential area for siting the G tube is however often critically small, leaving the operator little choice. Several steps may increase the potential area for placement: (a) use of ultrasound during the procedure may show the liver margin has moved cranially with gastric distension, opening a wider access window for puncture; (b) if dilated colon compromises access, it can be deflated using a 27-G needle, T-piece, and syringe under fluoroscopic control; (c) as with adults, cranial tilt of the needle and image intensifier may enable clearance of the of the upper margin of the colon. Confirmation ⫾ actual puncture in the lateral view is always helpful to ensure the colon is avoided (Fig 1A). Hardware must be avoided. In those children with abdominal wall defects (e.g., omphalocele) it is imperative to discuss with the surgeons the presence of any synthetic mesh or graft. Avoid traversing this during placement, and a site outside the mesh should be chosen. In children with cardiac pacemakers in situ, they are often placed over the left upper quadrant and are
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Fig 2. (A) Standard Cope loop catheter (gastrostomy tube), showing the tip standing proud of the pigtail. In one severely neurologically impaired child, the G tube migrated into the duodenum. The tip eroded through the bowel wall causing perforation and severe peritonitis. We then changed our design of G tube to that in (B). (B) MAC-LOC Dawson Mueller pigtail (gastrostomy tube) on the left. The size of the pigtail proved too small, leading to a tendency to erosion through the anterior gastric wall and abdominal wall in small children. We now use the pigtail catheter as shown on the right, a MAC-LOC Multipurpose drainage catheter. (C) A standard pediatric GJ tube (above), and a Carey-Alzate GJ tube, suitable for the newborn infants, below.
relatively large for these infants, leaving little space for access. A site as far away as possible should be chosen. Similar approach should be taken in children with a ventriculo-peritoneal shunt.17 Potential infection of hardware must be included in the consent discussion with parents preprocedure. Anatomical variants are not uncommon. Patients with isolate esophageal atresia (and a gasless stomach) may be referred for a G-tube placement for nutrition to promote growth while the esophageal gap narrows. This is technically possible by puncturing the stomach under ultrasound guidance using a 27-G needle, T-piece, and syringe and then inflating the stomach under fluoroscopy. Situs inversus, congenital diaphragmatic hernia, and other anatomical abnormalities are not contraindications to tube placement, but may render the placement more challenging. It behooves the radiologist to stress with the parents the possibility that a safe access route may not be technically possible.
Needle Puncture The stomach is punctured using an 18-G 4-cm-long BSDN entry needle (Cook, Bloomington, IN) preloaded with a pediatric retention suture (Cope, Pediatric Gastrointestinal Suture Anchor set, Cook) with a T-piece and contrast. Avoid using longer needles in the infant as the posterior wall of the stomach can easily be punctured in small infants. Once the intragastric location is confirmed with contrast through the needle, the retention suture is deployed with a 0.035⬙ wire (Fig 1B,C). It is important not to flush contrast through the needle when setting up the tray, as the sticky contrast will make deploying of the suture with the wire very difficult and the fine retention thread
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may snap. Gentle traction is placed on the retention suture using a light mosquito clamp on the end of the thread, to ensure apposition of the stomach wall to the anterior abdominal wall. In children with portal hypertension and known or suspected gastric varices, it is useful to puncture with a combination of real-time ultrasound, fluoroscopy, and simultaneous endoscopy to avoid traversing individual varices.
Tube Placement The tract is dilated with an appropriate-sized dilator. As the pediatric retention suture is fine, one must avoid excessive tension on it during dilation. A push-twist movement of the dilator, while transiently allowing some slack on the retention suture, usually avoids snapping the thread. It is at this point that care and gentleness are needed to avoid tearing a large hole in the gastric wall in infants. The neonatal tissues are fragile and tear easily, especially in the premature infant. The dilator is then removed and over the wire the pigtail catheter is placed (8, 10, or 12 Fr.). It was our practice to use a Cope loop pigtail catheter (Cook) (Fig 2A); we then switched to an Ultrathane MAC-LOC Dawson-Mueller pigtail tube (Fig 2B) and most recently we use a Ultrathane, MAC-LOC Multipurpose drainage catheter with a larger loop (Cook) (Fig 2B). When placing a GJ tube, one must choose whether to use glucagon or not (permits better gastric distension and avoids small bowel filling, but may delay passage of a wire through the pylorus). The duodenum is canulated from the stomach puncture using an angled catheter (e.g., JB1) and a soft floppy-tipped wire (e.g., Bentson). Both are advanced around the duodenum and negotiated to the proximal part of the jejunum, while genB. CONNOLLY
Fig 3. (A) Lateral fluoroscopy of stomach with a new pigtail G tube, showing a moderate pneumoperitoneum outlining the gastric wall. (B) Same patient after most of the air has been aspirated through a 27-G needle, to facilitate apposition of the anterior gastric wall to the abdominal wall. The liver is outlined by air.
tle traction is maintained on the retention thread with a light mosquito clamp. The tract is then dilated to 8 or 10 Fr., and then the GJ tube is then advanced over the wire, usually 8 or 10 Fr., rarely 12 Fr. (Ultrathane Pediatric Gastrojejunostomy Catheter, Cook) (Fig 2C). In the neonate, a Carey Alzate Coons Pediatric/Neonatal Gastrojejunostomy Catheter (Cook), cut to length to reach the proximal jejunum, is suitable (Fig 2C). Confirmation of the position and clearance of the transverse colon is recorded by images in different obliquities. The lateral view is always included to detect if the loop is in the peritoneum. This may occur if the crosspiece of the retention suture folds on itself into a V-shape and pulls through the gastric wall into the peritoneum. The lateral view also confirms clearance from the colon and estimates the degree of pneumoperitoneum. A small pneumoperitoneum is normal, but it is our practice to aspirate any significant pneumoperitoneum using a 27-G needle, T-piece, and syringe, placed in the epigastrium under fluoroscopy (Fig 3A,B). In those patients with a tracheoesophageal fistula who are ventilated and have a G tube placed, a tension pneumoperitoneum can occur immediately or early postprocedure. This should be deflated by a similar method to avoid intraabdominal tamponade and permit apposition of the stomach to the abdominal wall. Finally the retention suture is wrapped around a small roll of gauze and tape is applied to keep the roll secure. Polysporin is applied to the site and an adhesive dressing is applied. A variety of locking/securing devices supplied by different manufacturers may be useful in active children or those severely impaired who are liable to pull out their tubes. The rectal catheter is drained of barium and removed. GASTROINTESTINAL INTERVENTIONS—EMPHASIS ON CHILDREN
Postprocedure—Early It is imperative to keep the stomach empty using both nasogastric drainage and drainage via the new G tube. If a GJ tube has been placed, this is capped off. Following a minimum of 12 hours, and only after bowel sounds have returned, clear fluids (electrolyte solution) are commenced via the G or GJ tube (e.g., 5 mL every 2 hours). A very gradual increase of feeds occurs over the subsequent 36 to 48 hours, planned in conjunction with the dietician, reaching their feeding goal at 48 to 72 hours. Discharge from the hospital usually occurs at about 72 hours. The retention suture is cut flush with the skin after 14 days. Vigilance is imperative to look for signs or symptoms of peritonitis. This may be extremely difficult to detect in the severely neurologically impaired child, who may be irritable and spastic normally. In the first few days postinsertion any concern regarding tolerance of feeds, irritability, abdominal pain, or fever, a G-tube check is mandatory and performed with contrast and fluoroscopy. Feeds are discontinued and triple antibiotics are commenced at the clinical suggestion of peritonitis, even if the G-tube check is normal. Conservative treatment with a minimum of 72 hours of triple antibiotics and cessation of feeds is usually sufficient to treat a G-tube leak, whether documented or only suspected. A pneumoperitoneum can be aspirated even at this stage. Laparotomy is rarely required, but active clinical observation by the interventionalist as well as the surgical team for any deterioration is a must.
Postprocedure—Late Any tube, G or GJ, radiological, PEG, or surgical in nature requires ongoing maintenance, replacement, and revision and
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is subject to major or minor complications, etc.5,11,16,18-20 The family and clinicians need to be aware of this when undertaking tube placement.20 Stoma problems are common, such as superficial site infections. These usually settle with conservative measures such as saline soaks, Polysporin ointment, and rarely oral/IV antibiotics. Tube maintenance issues include tube blockage, dislodgment, and migration. In case the tube comes out, the parents are given a Foley catheter (one size smaller) to place through the stoma to maintain it open and permit feeds. The tract is considered mature after 6 weeks. Before this time, if the tube dislodges, then any tube replacement should be confirmed to be intragastric before recommencing feeds to avoid accidental intraperitoneal feeding. Eight weeks after primary insertion, feeds can be commenced through a replacement Foley once gastric contents are aspirated, without requiring a fluoroscopic check. Intussusception associated with GJ tubes, whether they contain a distal pigtail or a straight distal end, is not uncommon, especially in the young child.21-23 It is possible this may relate to the use of motility agents, uncoordinated peristalsis, and the size of the bowel lumen. The child may be asymptomatic or present with bilious vomiting or irritability with feeds. The diagnosis is made by US ⫾ fluoroscopy. Replacement of the GJ tube over a wire, with a shortened GJ tube without a distal pigtail, usually suffices to reduce the intussusception. We have, however, encountered one patient with ischemia of the bowel secondary to intussusception, despite tube replacement. As the tract matures, the tube may be replaced with a balloon tube (MicKey balloon) or a low profile button (12 Fr. Entristar or 14 Fr. MicKey button). Spontaneous closure of the stoma after elective removal is quick and rarely leads to leakage, as compared with PEG tubes.5,19,24 It is not infrequent that the lower end of the costal margin descends as the child grows, thus encroaching on the gastrostomy site. This may cause painful irritation sufficient to warrant a new G-tube placement.
Cecostomy Cecostomy tubes (C tubes) are small-caliber tubes placed radiologically by image-guidance into the cecum to permit largebowel irrigation. This enables evacuation in a controlled and timely manner, for those children who suffer from fecal incontinence.25-29 The benefits of a C tube include improved social acceptability because of lack of soiling, the ability to administer one’s own bowel irrigations, hence greater physical independence from caregivers giving rectal washouts, as well as numerous psychological benefits.30 Body-image issues can be a problem for some children and teenagers coping with a C tube.
Indications The commonest indication is in children with spina bifida or previous imperforate anus who have a patulous anus without sphincter tone, resulting in fecal incontinence. The C tube is not indicated in those with an intact anal sphincter. C tubes can be placed surgically, endoscopically, or radiologically.29,31,32 The technique described below is the radiological method.25-28 Although the technique is similar to a G tube, it is technically more challenging because of the variability of the anatomy, overlapping air-filled loops of bowel, and the higher risks of infection.
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Consent Parents and children need to be involved in the decision to place a cecostomy tube. Informed consent must be obtained, including the risks of peritonitis, stoma and site problems, and tube maintenance issues. In those with a ventriculoperitoneal shunt the real and yet infrequently seen risk of ascending ventriculitis and shunt infection must be discussed. Given the variability of the cecal position, parents must be forewarned that the tube may be sited anywhere in the abdomen, not always in the right lower quadrant. Occasionally when abnormal anatomy of the colon is predicted because of prior surgery, a watersoluble contrast enema may be requested before the procedure to aid in planning the C tube.
Sedation The procedure is usually performed under sedation and local anesthetic (see details in G&GJ section). For many, the C tube site is below their sensory level, which is a benefit in terms of pain control.
Preprocedure The bowel prep is achieved by 2 days of clear fluids by mouth and associated with phospha soda ingestion the night before (2-3 year ⫽ 5 ml; 4-6 year ⫽ 10 ml; 7-9 year ⫽ 20 ml; ⬎10 year ⫽ 45 ml). Antibiotic prophylaxis (Cefoxitin 25 mg/Kg IV) is given before the procedure.
Technique Latex precautions are exercised routinely as many patients with spina bifida are allergic to latex. Ultrasound and an indelible marker are used to map the liver, gallbladder, and urinary bladder. A large Foley catheter (22-26 Fr.) is placed in the rectum and attached to an enema inflator. Following the administration of glucagon (see the doses in G&GJ section), air is inflated into the rectum. The air is followed fluoroscopically as it retrogradely distends the sigmoid, descending, transverse, and ascending colon; and the cecum is identified ideally before filling of the small bowel (Fig 4A). Sometimes it is very difficult to clearly identify cecum from other overlapping air-filled loops of bowel (Fig 4B). It is important to spend time and care at this stage of the procedure, mapping out with fluoroscopy the anatomy. A safe access route is chosen avoiding the structures mapped and the VP shunt, if present (Fig 4C). Awareness of proximity to the iliac crest or lower costal margin is important to avoid site irritation problems. The cecum is punctured with an 18-G single-wall puncture, 7-cm-long needle (e.g., Merit, Medical, Ireland) preloaded with two pediatric retention sutures (Cope Pediatric Gastrointestinal Suture Anchor set, Cook), and the intraluminal position is confirmed with contrast. The retention sutures are then deployed with a 0.035⬙ Amplatz wire (Fig 5A), and gentle traction is placed on the threads with a light mosquito clamp. Over the wire, the tract is dilated with an 8 Fr. dilator, and then over the wire an 8 Fr. pigtail catheter (MAC-LOC Dawson-Mueller, Cook) is placed (Fig 5B,C). We advance the wire, the dilator, and the pigtail only a short way into the cecal lumen, to avoid having to withdraw too much contaminated wire or tubing back through the tract. The tube is left to free drainage and venting for the following week. The retention sutures are rolled over gauze and B. CONNOLLY
Fig 4. (A) Air-filled cecum clearly identified on AP fluoroscopy, with the access needle prepared to puncture. (B) AP view of the right side of the abdomen with multiple overlapping loops of air-filled bowel. (C) Similar image in another child with a VP shunt seen in the epigastrium (arrows).
secured with tape. The site is dressed with Polysporin and an adhesive dressing. The rectal Foley catheter is removed.
ally adequate, but the latter may result in less effective bowel evacuations.
Postprocedure—Early
Postprocedure—Late
Fluids by mouth can be commenced once bowel sounds return, progressing gradually to diet as tolerated. Our current practice is for a single dose of antibiotics before the procedure. Only if difficulties are encountered during the procedure are triple antibiotics employed for 5 days. The patient is discharged home once eating well, usually after 3 to 5 days. The patient’s usual regimen for washouts is employed after 3 days. Bowel irrigations through the tube are commenced 10 days after C-tube placement. The retention sutures are cut after 14 days. Complications have included placement into a redundant sigmoid loop, ileal placement, peritonitis, VP shunt infection, pelvic abscess, as well as numerous site and tube maintenance problems. Ileal and sigmoid placements of tubes have been function-
After 8 weeks the pigtail catheter is changed to a low-profile device or button, e.g., the “Chait TrapdoorTM” (Pediatric Cecostomy Catheter, Cook) (Fig 6). Due to fecal concretions changing the pigtail for the TrapdoorTM over a straight wire 0.35⬙ is sometimes difficult. Use of a hydrophilic glide wire is often helpful. The TrapdoorsTM come in two lengths to accommodate those patients with a thicker abdominal wall. This is then electively replaced annually. As the spring shape of the Chait Trapdoor TM also stiffens with age and with fecal concretions, it becomes very difficult to remove it. Therefore at annual tube changes, the old tube is not removed. Instead a wire is passed only part way into the old C tube, and the external flap of the old tube is then cut around the wire. The new tube is
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Fig 5. (A) AP fluoroscopic view of an air-filled cecum with two retention sutures deployed and an Amplatz wire inserted a short way (stiff part) into the cecal lumen. (B, C) Cecostomy tube in position with contrast in the colon. Note the confusing collection of air-filled loops and VP shunt (B) and spinal hardware (C).
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B. CONNOLLY
manage, may contain a cartilaginous remnant, and can easily perforate during balloon dilation.38 Contraindications include uncorrectable coagulopathy. Relative contraindications include a very brittle or unsafe airway, when dilation can be attempted from below, if the patient has a G tube.
Sedation Most cases are done as a day case. Informed consent is obtained from the parents, outlining the risks of bleeding, esophageal tear, mediastinitis, aspiration, and recurrence of symptoms/ stricture requiring further dilatations.35,39 Dilations are performed under anesthesia, using either intubation or propofol infusion anesthesia, at the discretion of the anesthetist. In those children with epidermolysis bullosa, great care is needed by the anesthetist to avoid blistering of the face, mouth, or airway.
Technique
Fig 6. Short (left) and long (right) trap door cecostomy tube.
advanced over the wire, in so doing pushing the old tube into the cecal lumen, to be passed per rectum later. Retention of one old tube has occurred on one occasion. Irrigations are usually performed every second day. Each child has a somewhat individual routine. The solution used is a phosphate solution 2-4 ml/Kg, followed by salt–water solution until the bowel irrigation fluid is clear. Signs and symptoms of phosphate excess have been seen and include nausea and vomiting, lethargy, and sweating. A reduction in the dose of phosphate used is then required. Liberal oral fluids on the day of the irrigation are also encouraged.
Esophageal Dilatation Indications and Contraindications Unlike in adults where a malignancy is the commonest cause of esophageal stricture, in neonates and children, the common causes are benign, e.g., caustic ingestion, achalasia, and an anastomotic stricture following tracheoesophageal fistula (TEF) repair33-35 (Fig 7A,B). The latter usually occurs in the upper one-third of the esophagus and may require several balloon dilatations to maintain adequate patency. Other indications for stricture dilation include epidermolysis bullosa strictures,36,37 reflux esophagitis with stricture, and rarely, congenital strictures (Fig 7C). Note the latter is difficult to GASTROINTESTINAL INTERVENTIONS—EMPHASIS ON CHILDREN
Usually esophageal dilation is done through the mouth. If performed through a gastrostomy stoma, temporarily remove the G tube over a wire and advance the wire and the balloon up the esophagus from below. From above, the oropharynx is negotiated using a floppy wire (e.g., 0.035⬙ Bentson) and an angled catheter (e.g., JBI 5 Fr.). The upper esophageal pouch is identified with minimum amount of contrast, avoiding overspill into the airway. As the endotracheal tubes (ET tubes) in children are usually uncuffed, this can easily occur. The length and level of the stricture are identified. Then the wire is advanced down into the stomach and the intragastric position is confirmed. Over the same wire, the catheter is exchanged for a suitably sized balloon e.g., 6, 10, 15 mm, or greater for the patients with achalasia. The size is judged by the child’s native esophagus, below the stricture. A 5- or 6-mm balloon is usually a good initial size in an infant post-TEF repair. The balloon is inflated using one-half strength contrast diluted with water, until the waist is seen; this is then stretched gently until the waist disappears. The inflation may be done by hand or by manometer. The balloon is held inflated for less than 30 seconds, to avoid esophageal mucosal ischemia. A contrast check through the distal end of the catheter is performed at the end of the procedure to evaluate the mural integrity and any possible esophageal tear or leak. The appearance often is not any better on immediate check than predilation. The contrast is aspirated from the upper pouch as best as possible, to avoid reflux and overspill into the airway, remembering the pediatric uncuffed ET tubes. Should aspiration occur, the patient requires active observation and may even require an overnight admission.
Postprocedure—Early The patients are allowed clear fluids that evening and full fluids the following day. Antibiotics are not usually employed. Some centers use steroids for those children with epidermolysis bullosa pre- and postdilation to help prevent blistering and recurrent stricture, although it is not our practice to do so.
Postprocedure—Late Many children require repeated dilatations (few require ⬎4) at varying intervals in time, with a high rate of success (up to 85%).34,40,41 Experience with stenting of the esophagus is very limited in children. Given that most strictures are benign and because of
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Fig 7. (A, B, C) Examples of pediatric esophageal strictures: (A) a mild fixed smooth narrowing due to caustic ingestion, (B) a post TEF anastomotic stricture, and (C) a focal stricture of epidermolysis bullosa.
issues adjusting to the child’s growth, and the expected life span for children, stenting is generally avoided unless all other measures have failed. The role of stenting in children is therefore yet to be determined. Choice of suitably sized stents that are removable for the small child remains an issue.
Other Bowel Dilatations Balloon dilation of other areas of the bowel (duodenal strictures, strictures of the small or large bowel secondary to necrotizing enterocolitis, or surgical anastomoses) are less common.42-46 The basic principles as outlined for esophageal dilation apply. There is increasing difficulty achieving any dilation with increasing distance and tortuosity from the orifice of access (mouth, anus, stoma). With tortuosity it is important to avoid excessive centrifugal pressure on the convexity of the guide wire which causes stretching of the bowel and increases the risk of bowel tear or perforation. This is especially true of the neonate or infant whose tissues are more fragile than an older person’s. A pediatric surgeon should be aware and available when these distal dilatations are performed, should the need for emergency laparotomy be required. The likelihood of success decreases as the distance from the access route increases. As with other intestinal interventions, those with con-
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genital heart disease require antibiotic prophylaxis for GI interventional procedures that can be anticipated to cause bleeding.
Miscellaneous Although not strictly enteric interventions, other abdominal interventions include percutaneous transhepatic cholangiography, percutaneous transhepatic transcholecystic cholangiography, pancreatic pseudocyst drainage, liver and spleen biopsies, as well as drainage of intraabdominal abscesses secondary to appendicitis, Crohn’s Disease, and other inflammatory causes. A full description of these procedures is beyond the scope of this article. Although the techniques may be similar to those in adults, however, the size of needles and tubes employed, the indications and pathologies, and the choice of sedation or anesthesia are usually quite different.
References 1. Towbin RB, Ball WS Jr, Bissett GS 3rd: Percutaneous gastrostomy and percutaneous gastrojejunostomy in children: Antegrade approach. Radiology 168(2):473-476, 1988 2. Cahill AM, Kaye RD, Fitz CR, et al: “Push-pull” gastrostomy: A new technique for percutaneous gastrostomy tube insertion in the neonate and young infant. Pediatr Radiol 31(8):550-554, 2001 B. CONNOLLY
3. Wilson L, Oliva-Hemker M: Percutaneous endoscopic gastrostomy in small medically complex infants. Endoscopy 33(5):433-436, 2001 4. Chait PG, Weinberg J, Connolly BL, et al: Retrograde percutaneous gastrostomy and gastrojejunostomy in 505 children: A 4 1/2-year experience. Radiology 201(3):691-695, 1996 5. Kobak GE, McClenathan DT, Schurman SJ: Complications of removing percutaneous endoscopic gastrostomy tubes in children. J Pediatr Gastroenterol Nutr 30(4):404-407, 2000 6. Wollman B, D’Agostino HB, Walus-Wigle JR, et al: Radiologic, endoscopic, and surgical gastrostomy: An institutional evaluation and meta-analysis of the literature. Radiology 197(3):699-704, 1995 7. McLoughlin RF, So B, Gray RR: Fluoroscopically guided percutaneous gastrostomy: Current status. Can Assoc Radiol J 47(1):10-15, 1996 8. Goretsky MF, Johnson N, Farrell M, et al: Alternative techniques of feeding gastrostomy in children: A critical analysis. J Am Coll Surg 182(3):233-240, 1996 9. Marx MV, Williams DM, Perkins AJ, et al: Percutaneous feeding tube placement in pediatric patients: Immediate and 30-day results. J Vasc Interv Radiol 7(1):107-115, 1996 10. Hofner G, Behrens R, Koch A, et al: Enteral nutritional support by percutaneous endoscopic gastrostomy in children with congenital heart disease. Pediatr Cardiol 21(4):341-346, 2000 11. Ramage IJ, Geary DF, Harvey E, et al: Efficacy of gastrostomy feeding in infants and older children receiving chronic peritoneal dialysis. Perit Dial Int 19(3):231-236, 1999 12. Ramage IJ, Harvey E, Geary DF, et al: Complications of gastrostomy feeding in children receiving peritoneal dialysis. Pediatr Nephrol 13(3):249-252, 1999 13. Barron MA, Duncan DS, Green GJ, et al: Efficacy and safety of radiologically placed gastrostomy tubes in paediatric haematology/ oncology patients. Med Pediatr Oncol 34(3):177-182, 2000 14. Peters JM, Simpson P, Tolia V: Experience with gastrojejunal feeding tubes in children. Am J Gastroenterol. 92(3):476-480, 1997 15. Lu DS, Mueller PR, Lee MJ, et al: Gastrostomy conversion to transgastric jejunostomy: Technical problems, causes of failure, and proposed solutions in 63 patients. Radiology 187(3):679-683, 1993 16. Day AS, Beasley SW, Meads A, et al: Morbidity associated with gastrostomy placement in children demands an ongoing integrated approach to care. NZ Med J Apr 13 114(1129):164-167, 2001 17. Sane SS, Towbin A, Bergey EA, et al: Percutaneous gastrostomy tube placement in patients with ventriculoperitoneal shunts. Pediatr Radiol 28(7):521-523, 1998 18. Godbole P, Margabanthu G, Crabbe DC, Thomas A, Puntis JW, Abel G, Arthur RJ, Stringer MD: Limitations and uses of gastrojejunal feeding tubes. Arch Dis Child 86(2):134-137, 2002 19. Gordon JM, Langer JC: Gastrocutaneous fistula in children after removal of gastrostomy tube: Incidence and predictive factors. J Pediatr Surg 4(9):1345-1346, 1999 20. Segal D, Michaud L, Guimber D, et al: Late-onset complications of percutaneous endoscopic gastrostomy in children. J Pediatr Gastroenterol Nutr 33(4):495-500, 2001 21. Connolly BL, Chait PG, Siva-Nandan R, et al: Recognition of intussusception around gastrojejunostomy tubes in children. AJR Am J Roentgenol 170(2):467-470, 1998 22. Hughes UM, Connolly BL, Chait PG, et al: Further report of smallbowel intussusceptions related to gastrojejunostomy tubes. Pediatr Radiol 30(9):614-617, 2000 23. Hughes U, Connolly B: Small-bowel intussusceptions occurring around nasojejunal enteral tubes—Three cases occurring in children. Pediatr Radiol 31(6):456-457, 2001 24. Borge MA, Vesely TM, Picus D: Gastrostomy button placement through percutaneous gastrostomy tracts created with fluoroscopic guidance: Experience in 27 children. J Vasc Interv Radiol. 6(2):179183, 1995
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25. Shandling B, Chait PG, Richards HF: Percutaneous cecostomy: A new technique in the management of fecal incontinence. J Pediatr Surg 31(4):534-537, 1996 26. Chait PG, Shandling B, Richards HF: The cecostomy button. J Pediatr Surg 32(6):849-851, 1997 27. Chait PG, Shandling B, Richards HM, et al: Fecal incontinence in children: Treatment with percutaneous cecostomy tube placement—A prospective study. Radiology 203(3):621-624, 1997 28. Chait PG, Shlomovitz E, Connolly BL, et al: Percutaneous cecostomy: Updates in technique and patient care. Radiology 227(1):246250[Epub 2003 Feb 11], 2003 29. Lee SL, Rowell S, Greenholz SK: Therapeutic cecostomy tubes in infants with imperforate anus and caudal agenesis. J Pediatr Surg 37(3):345-347, 2002 30. Youssef NN, Barksdale Jr E, Griffiths JM, et al: Management of intractable constipation with antegrade enemas in neurologically intact children. J Pediatr Gastroenterol Nutr 34(4):402-405, 2002 31. Driver CP, Barrow C, Fishwick J, et al: The Malone antegrade colonic enema procedure: Outcome and lessons of 6 years’ experience. Pediatr Surg Int 13(5-6):370-372, 1998 32. De Peppo F, Iacobelli BD, De Gennaro M, et al: Percutaneous endoscopic cecostomy for antegrade colonic irrigation in fecally incontinent children. Endoscopy 31(6):501-503, 1999 33. Fasulakis S, Andronikou S: Balloon dilatation in children for oesophageal strictures other than those due to primary repair of oesophageal atresia, interposition or restrictive fundoplication. Pediatr Radiol 33(10):682-687, 2003 34. Yeming W, Somme S, Chenren S, et al: Balloon catheter dilatation in children with congenital and acquired esophageal anomalies. J Pediatr Surg 37(3):398-402, 2002 35. Said M, Mekki M, Golli M, et al: Balloon dilatation of anastomotic strictures secondary to surgical repair of oesophageal atresia. Br J Radiol 76(901):26-31, 2003 36. Fujimoto T, Lane GJ, Miyano T, et al: Esophageal strictures in children with recessive dystrophic epidermolysis bullosa: Experience of balloon dilatation in nine cases. J Pediatr Gastroenterol Nutr 27(5):524-529, 1998 37. Castillo RO, Davies YK, Lin YC, et al: Management of esophageal strictures in children with recessive dystrophic epidermolysis bullosa. J Pediatr Gastroenterol Nutr 34(5):535-541, 2002 38. Feng FH, Kong MS: Congenital esophageal stenosis treated with endoscopic balloon dilation: Report of one case. Acta Paediatr Taiwan 40(5):351-353, 1999 39. Panieri E, Millar AJ, Rode H, et al: Iatrogenic esophageal perforation in children: Patterns of injury, presentation, management, and outcome. J Pediatr Surg 31(7):890-895, 1996 40. Amaral J, Chait PG, Connolly BL: Esophageal balloon dilatation under fluoroscopic guidance in children—Experience of 172 dilatations. J Vasc Interf Radiol (S1–S165) 13(2;Part II):S71 (abstr.) 41. Montilla-Gonzalez Z, Torres P, Rivero E, Moreno E, Romer H: [Usefulness of dilatation in esophageal stricture in children] (abstr.) GEN 47(2):57-60, 1993 42. Renfrew DL, Smith WL, Pringle KC: Per anal balloon dilatation of a post-necrotizing enterocolitis stricture of the sigmoid colon. Pediatr Radiol 16(4):320-321, 1986 43. Dobson HM, Robertson DA: Balloon catheter dilatation of an ileocolic stricture. Clin Radiol 39(2):202-204, 1988 44. de Lange EE, Shaffer HA Jr: Rectal strictures: Treatment with fluoroscopically guided balloon dilation. Radiology 178(2):475-479, 1991 45. Peer A, Klin B, Vinograd I: Balloon catheter dilatation of focal colonic strictures following necrotizing enterocolitis. Cardiovasc Intervent Radiol 16(4):248-250, 1993 46. Johnstone AJ, Hendry GM, Orr JD: Case report: Duodenal and jejunal strictures treated with balloon dilatation through a duodenostomyClin Radiol 45(3):208, 1992
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Although the fundamental principles of interventional and minimally invasive image-guided techniques are the same in children as in adults, nonetheless the spectrum of diseases, the pediatric approach, and the devices used differ significantly from those in adults. The following is a general overview of image-guided gastrointestinal interventions in children and neonates, with emphasis on those aspects peculiar to children. Many of the facets and tips have been learned the hard way over the years, in a busy pediatric practice. Although there are several potential ways to do some of these procedures, the description below reflects our practice and experience. In general terms, minimizing radiation dose is a significant responsibility for the pediatric interventionalist. Reducing the number of exposures, reliance on last image hold, low-dose pulse fluoroscopy, and tight coning are all important. Protection for the radiologist is equally important, but sometimes difficult to achieve, given the small size of many of the patients. © 2003 Elsevier Inc. All rights reserved.
Gastrostomy and Gastrojejunostomy Tubes For infants unable to feed by mouth due to congenital or acquired abnormalities, gastrostomy (G) and gastrojejunostomy (GJ) tubes are life-preserving devices that enable adequate nutrition to be sustained. As distinct from adults in whom feeding tubes are frequently a palliative measure, most children with G and GJ tubes live for a significant length of time; the cumulative effect on society and health care is therefore significant. There are many ways to place feeding tubes, e.g., surgical, PEG, “push–pull”1-3; however, the technique described below is the retrograde radiological method.4 While its advantages lie in its simplicity of placement, suitable for even the most medically fragile of children, its low morbidity, and its low complication rate, these must be balanced against the ease at which it may become accidentally dislodged.5-9
Indications and Contraindications The indications for a G-tube include those patients with oromotor dysfunction, inability to feed or swallow safely, or inability to achieve adequate intake for their caloric needs. The majority of those referred suffer from neurological disorders, e.g., cerebral palsy, syndromic abnormalities, with associated failure to thrive. Children with high caloric needs include those with chronic renal or cardiac failure (to promote growth before surgery or organ transplant) and cystic fibrosis.10-12 Patients with oncological disorders with predictable weight loss, mucositis,
From the Image Guided Therapy Centre, Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, Toronto M5G 1X8, Canada. © 2003 Elsevier Inc. All rights reserved. 1089-2516/03/0604-0006$30.00/0 doi:10.1053/j.tvir.2003.10.001
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or odynophagia are also potential candidates.13 Those with specific metabolic demands (e.g., glycogen storage diseases or ketogenic diets) and those requiring specific medications (e.g., HIV) account for a minority of patients. The indications for a GJ tube include all of the above in those patients with severe gastroesophageal reflux, rendering them at risk for aspiration of gastric contents if fed through a G tube.14 In our institution, children rarely undergo fundoplication, unless they have failed a period of nutrition through a GJ tube. A trial of G feeds is often attempted initially because of maintenance issues with GJ tubes.14 Conversion from a G to a GJ tube is usually easy, but does depend on the angle of the tract.15 A minority of children require a venting G tube and a feeding GJ tube, e.g., Superior mesenteric artery syndrome. There are relatively few contraindications to tube placement; however, they include uncorrectable coagulopathy, occasionally severe visceromegaly or unfavorable anatomy that precludes safe access, and lack of parental consent.
Decision The decision to proceed with a G or GJ tube requires careful consideration and a multidisciplinary integrated approach to care.16 It requires access to the necessary support structure (educator, dietician, occupational therapists, pediatrician, etc.) for ongoing care for the children and their tube maintenance issues, not just the interventional team. Parents must be actively involved in this decision and “buy in” to the decision to proceed, as many are initially reluctant to take this step.10
Consent Informed consent is obtained, outlining the risks including bleeding, infection leading to peritonitis, damage to any other adjacent organ, inability to obtain a safe access route, local site problems, as well as on-going tube maintenance issues.16 The risks of sedation or general anesthetic must also be included.
Sedation A radiologically placed retrograde G or GJ tube can be placed under local anesthetic alone, sedation and local anesthetic, or general anesthetic plus local anesthetic, depending on what is the safest for the patient’s overall medical condition. The following are the regimens and doses we use: Chloral hydrate, 50 to 100 mg/Kg for neonates and infants ⬍6 months or ⬍10 kg; a combination of Nembutal 3 mg/Kg and Demerol 1 mg/Kg for children 10 to 30 kg; a combination of Diazemul 0.1 mg/Kg and Demerol 1 mg/Kg for older children ⬎30 kg. With the latter two combinations, we use the option of giving a second dose if needed. The local anesthetic used is 1% lidocaine, 0.5 ml/Kg, or Marcaine 0.25%, 1 mL/Kg. Many of the children are medically so fragile that local anesthetic alone represents the safest method by which to place a G tube. Pacifiers, distraction meth-
Techniques in Vascular and Interventional Radiology, Vol 6, No 4 (December), 2003: pp 182-191
Fig 1. (A) Lateral fluoroscopy showing an air-filled stomach with NG tube in situ, and barium with air in the colon. A safe access route is seen, above the transverse colon, indicated by metal instrument. (B) Lateral fluoroscopy showing an air-filled stomach with needle entering the stomach above the colon. Contrast drips freely from the needle into the stomach cavity. (C) AP view of the same case showing the needle after puncture, and contrast puddling around the NG tube.
ods, videos, music, etc. are all useful adjunctive tools, depending on the child’s neurological ability.
fill. If the patient has a small silastic feeding tube in place, it is prudent to exchange it for a regular NG tube for efficient gastric drainage postprocedure.
Technique Antibiotics are given before the procedure (Cephazolin 40 mg/ Kg, to a maximum of 2 g). This is also used for children who require cardiac prophylaxis. The lower limits of the liver and spleen are mapped with ultrasound (e.g., 10 MHz linear probe) using an indelible marker on the skin. The position of the lower left costal margin is also marked on the skin before inflation of the stomach with air, as the costal margin in small infants is not prominent, and proximity to it may be overlooked when placing the tube. Ideally one should leave at least two finger breadths between the ribs and the chosen G tube site, as the costal margin descends as the child grows. It may therefore with time encroach on the G tube site and cause severe irritation. Dilute barium (4:1) is administered by rectum by the hangingbag technique (through a 16-22 Fr. Foley catheter with the balloon inflated) to outline the transverse colon. In children with Hirschsprung’s disease water-soluble contrast should be used, rather than barium. Glucagon is administered intravenously; dosage is usually empirically based on patient’s size rather than per kilogram calculation, although such doses are available (rule of thumb: 0.2 mg for the neonate, 0.3 mg for the infant and toddler, 0.4 mg for young child, and 0.5 for the older child). Following the administration of glucagon, air is inflated into the stomach via a nasogastric tube under fluoroscopic control, ensuring that the tip of the NG is within the stomach and not through the pylorus, and that the small bowel does not GASTROINTESTINAL INTERVENTIONS—EMPHASIS ON CHILDREN
Choice of Site Once the stomach is moderately tense with air, a site is chosen below liver, spleen, and left costal margin, and above transverse colon. The ideal location is lateral to the rectus abdominus muscle. If this is not possible, then a midline G tube is next considered; least ideal is one through the rectus muscle. The latter may be acceptable in those children who are hypotonic and severely impaired. The potential area for siting the G tube is however often critically small, leaving the operator little choice. Several steps may increase the potential area for placement: (a) use of ultrasound during the procedure may show the liver margin has moved cranially with gastric distension, opening a wider access window for puncture; (b) if dilated colon compromises access, it can be deflated using a 27-G needle, T-piece, and syringe under fluoroscopic control; (c) as with adults, cranial tilt of the needle and image intensifier may enable clearance of the of the upper margin of the colon. Confirmation ⫾ actual puncture in the lateral view is always helpful to ensure the colon is avoided (Fig 1A). Hardware must be avoided. In those children with abdominal wall defects (e.g., omphalocele) it is imperative to discuss with the surgeons the presence of any synthetic mesh or graft. Avoid traversing this during placement, and a site outside the mesh should be chosen. In children with cardiac pacemakers in situ, they are often placed over the left upper quadrant and are
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Fig 2. (A) Standard Cope loop catheter (gastrostomy tube), showing the tip standing proud of the pigtail. In one severely neurologically impaired child, the G tube migrated into the duodenum. The tip eroded through the bowel wall causing perforation and severe peritonitis. We then changed our design of G tube to that in (B). (B) MAC-LOC Dawson Mueller pigtail (gastrostomy tube) on the left. The size of the pigtail proved too small, leading to a tendency to erosion through the anterior gastric wall and abdominal wall in small children. We now use the pigtail catheter as shown on the right, a MAC-LOC Multipurpose drainage catheter. (C) A standard pediatric GJ tube (above), and a Carey-Alzate GJ tube, suitable for the newborn infants, below.
relatively large for these infants, leaving little space for access. A site as far away as possible should be chosen. Similar approach should be taken in children with a ventriculo-peritoneal shunt.17 Potential infection of hardware must be included in the consent discussion with parents preprocedure. Anatomical variants are not uncommon. Patients with isolate esophageal atresia (and a gasless stomach) may be referred for a G-tube placement for nutrition to promote growth while the esophageal gap narrows. This is technically possible by puncturing the stomach under ultrasound guidance using a 27-G needle, T-piece, and syringe and then inflating the stomach under fluoroscopy. Situs inversus, congenital diaphragmatic hernia, and other anatomical abnormalities are not contraindications to tube placement, but may render the placement more challenging. It behooves the radiologist to stress with the parents the possibility that a safe access route may not be technically possible.
Needle Puncture The stomach is punctured using an 18-G 4-cm-long BSDN entry needle (Cook, Bloomington, IN) preloaded with a pediatric retention suture (Cope, Pediatric Gastrointestinal Suture Anchor set, Cook) with a T-piece and contrast. Avoid using longer needles in the infant as the posterior wall of the stomach can easily be punctured in small infants. Once the intragastric location is confirmed with contrast through the needle, the retention suture is deployed with a 0.035⬙ wire (Fig 1B,C). It is important not to flush contrast through the needle when setting up the tray, as the sticky contrast will make deploying of the suture with the wire very difficult and the fine retention thread
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may snap. Gentle traction is placed on the retention suture using a light mosquito clamp on the end of the thread, to ensure apposition of the stomach wall to the anterior abdominal wall. In children with portal hypertension and known or suspected gastric varices, it is useful to puncture with a combination of real-time ultrasound, fluoroscopy, and simultaneous endoscopy to avoid traversing individual varices.
Tube Placement The tract is dilated with an appropriate-sized dilator. As the pediatric retention suture is fine, one must avoid excessive tension on it during dilation. A push-twist movement of the dilator, while transiently allowing some slack on the retention suture, usually avoids snapping the thread. It is at this point that care and gentleness are needed to avoid tearing a large hole in the gastric wall in infants. The neonatal tissues are fragile and tear easily, especially in the premature infant. The dilator is then removed and over the wire the pigtail catheter is placed (8, 10, or 12 Fr.). It was our practice to use a Cope loop pigtail catheter (Cook) (Fig 2A); we then switched to an Ultrathane MAC-LOC Dawson-Mueller pigtail tube (Fig 2B) and most recently we use a Ultrathane, MAC-LOC Multipurpose drainage catheter with a larger loop (Cook) (Fig 2B). When placing a GJ tube, one must choose whether to use glucagon or not (permits better gastric distension and avoids small bowel filling, but may delay passage of a wire through the pylorus). The duodenum is canulated from the stomach puncture using an angled catheter (e.g., JB1) and a soft floppy-tipped wire (e.g., Bentson). Both are advanced around the duodenum and negotiated to the proximal part of the jejunum, while genB. CONNOLLY
Fig 3. (A) Lateral fluoroscopy of stomach with a new pigtail G tube, showing a moderate pneumoperitoneum outlining the gastric wall. (B) Same patient after most of the air has been aspirated through a 27-G needle, to facilitate apposition of the anterior gastric wall to the abdominal wall. The liver is outlined by air.
tle traction is maintained on the retention thread with a light mosquito clamp. The tract is then dilated to 8 or 10 Fr., and then the GJ tube is then advanced over the wire, usually 8 or 10 Fr., rarely 12 Fr. (Ultrathane Pediatric Gastrojejunostomy Catheter, Cook) (Fig 2C). In the neonate, a Carey Alzate Coons Pediatric/Neonatal Gastrojejunostomy Catheter (Cook), cut to length to reach the proximal jejunum, is suitable (Fig 2C). Confirmation of the position and clearance of the transverse colon is recorded by images in different obliquities. The lateral view is always included to detect if the loop is in the peritoneum. This may occur if the crosspiece of the retention suture folds on itself into a V-shape and pulls through the gastric wall into the peritoneum. The lateral view also confirms clearance from the colon and estimates the degree of pneumoperitoneum. A small pneumoperitoneum is normal, but it is our practice to aspirate any significant pneumoperitoneum using a 27-G needle, T-piece, and syringe, placed in the epigastrium under fluoroscopy (Fig 3A,B). In those patients with a tracheoesophageal fistula who are ventilated and have a G tube placed, a tension pneumoperitoneum can occur immediately or early postprocedure. This should be deflated by a similar method to avoid intraabdominal tamponade and permit apposition of the stomach to the abdominal wall. Finally the retention suture is wrapped around a small roll of gauze and tape is applied to keep the roll secure. Polysporin is applied to the site and an adhesive dressing is applied. A variety of locking/securing devices supplied by different manufacturers may be useful in active children or those severely impaired who are liable to pull out their tubes. The rectal catheter is drained of barium and removed. GASTROINTESTINAL INTERVENTIONS—EMPHASIS ON CHILDREN
Postprocedure—Early It is imperative to keep the stomach empty using both nasogastric drainage and drainage via the new G tube. If a GJ tube has been placed, this is capped off. Following a minimum of 12 hours, and only after bowel sounds have returned, clear fluids (electrolyte solution) are commenced via the G or GJ tube (e.g., 5 mL every 2 hours). A very gradual increase of feeds occurs over the subsequent 36 to 48 hours, planned in conjunction with the dietician, reaching their feeding goal at 48 to 72 hours. Discharge from the hospital usually occurs at about 72 hours. The retention suture is cut flush with the skin after 14 days. Vigilance is imperative to look for signs or symptoms of peritonitis. This may be extremely difficult to detect in the severely neurologically impaired child, who may be irritable and spastic normally. In the first few days postinsertion any concern regarding tolerance of feeds, irritability, abdominal pain, or fever, a G-tube check is mandatory and performed with contrast and fluoroscopy. Feeds are discontinued and triple antibiotics are commenced at the clinical suggestion of peritonitis, even if the G-tube check is normal. Conservative treatment with a minimum of 72 hours of triple antibiotics and cessation of feeds is usually sufficient to treat a G-tube leak, whether documented or only suspected. A pneumoperitoneum can be aspirated even at this stage. Laparotomy is rarely required, but active clinical observation by the interventionalist as well as the surgical team for any deterioration is a must.
Postprocedure—Late Any tube, G or GJ, radiological, PEG, or surgical in nature requires ongoing maintenance, replacement, and revision and
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is subject to major or minor complications, etc.5,11,16,18-20 The family and clinicians need to be aware of this when undertaking tube placement.20 Stoma problems are common, such as superficial site infections. These usually settle with conservative measures such as saline soaks, Polysporin ointment, and rarely oral/IV antibiotics. Tube maintenance issues include tube blockage, dislodgment, and migration. In case the tube comes out, the parents are given a Foley catheter (one size smaller) to place through the stoma to maintain it open and permit feeds. The tract is considered mature after 6 weeks. Before this time, if the tube dislodges, then any tube replacement should be confirmed to be intragastric before recommencing feeds to avoid accidental intraperitoneal feeding. Eight weeks after primary insertion, feeds can be commenced through a replacement Foley once gastric contents are aspirated, without requiring a fluoroscopic check. Intussusception associated with GJ tubes, whether they contain a distal pigtail or a straight distal end, is not uncommon, especially in the young child.21-23 It is possible this may relate to the use of motility agents, uncoordinated peristalsis, and the size of the bowel lumen. The child may be asymptomatic or present with bilious vomiting or irritability with feeds. The diagnosis is made by US ⫾ fluoroscopy. Replacement of the GJ tube over a wire, with a shortened GJ tube without a distal pigtail, usually suffices to reduce the intussusception. We have, however, encountered one patient with ischemia of the bowel secondary to intussusception, despite tube replacement. As the tract matures, the tube may be replaced with a balloon tube (MicKey balloon) or a low profile button (12 Fr. Entristar or 14 Fr. MicKey button). Spontaneous closure of the stoma after elective removal is quick and rarely leads to leakage, as compared with PEG tubes.5,19,24 It is not infrequent that the lower end of the costal margin descends as the child grows, thus encroaching on the gastrostomy site. This may cause painful irritation sufficient to warrant a new G-tube placement.
Cecostomy Cecostomy tubes (C tubes) are small-caliber tubes placed radiologically by image-guidance into the cecum to permit largebowel irrigation. This enables evacuation in a controlled and timely manner, for those children who suffer from fecal incontinence.25-29 The benefits of a C tube include improved social acceptability because of lack of soiling, the ability to administer one’s own bowel irrigations, hence greater physical independence from caregivers giving rectal washouts, as well as numerous psychological benefits.30 Body-image issues can be a problem for some children and teenagers coping with a C tube.
Indications The commonest indication is in children with spina bifida or previous imperforate anus who have a patulous anus without sphincter tone, resulting in fecal incontinence. The C tube is not indicated in those with an intact anal sphincter. C tubes can be placed surgically, endoscopically, or radiologically.29,31,32 The technique described below is the radiological method.25-28 Although the technique is similar to a G tube, it is technically more challenging because of the variability of the anatomy, overlapping air-filled loops of bowel, and the higher risks of infection.
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Consent Parents and children need to be involved in the decision to place a cecostomy tube. Informed consent must be obtained, including the risks of peritonitis, stoma and site problems, and tube maintenance issues. In those with a ventriculoperitoneal shunt the real and yet infrequently seen risk of ascending ventriculitis and shunt infection must be discussed. Given the variability of the cecal position, parents must be forewarned that the tube may be sited anywhere in the abdomen, not always in the right lower quadrant. Occasionally when abnormal anatomy of the colon is predicted because of prior surgery, a watersoluble contrast enema may be requested before the procedure to aid in planning the C tube.
Sedation The procedure is usually performed under sedation and local anesthetic (see details in G&GJ section). For many, the C tube site is below their sensory level, which is a benefit in terms of pain control.
Preprocedure The bowel prep is achieved by 2 days of clear fluids by mouth and associated with phospha soda ingestion the night before (2-3 year ⫽ 5 ml; 4-6 year ⫽ 10 ml; 7-9 year ⫽ 20 ml; ⬎10 year ⫽ 45 ml). Antibiotic prophylaxis (Cefoxitin 25 mg/Kg IV) is given before the procedure.
Technique Latex precautions are exercised routinely as many patients with spina bifida are allergic to latex. Ultrasound and an indelible marker are used to map the liver, gallbladder, and urinary bladder. A large Foley catheter (22-26 Fr.) is placed in the rectum and attached to an enema inflator. Following the administration of glucagon (see the doses in G&GJ section), air is inflated into the rectum. The air is followed fluoroscopically as it retrogradely distends the sigmoid, descending, transverse, and ascending colon; and the cecum is identified ideally before filling of the small bowel (Fig 4A). Sometimes it is very difficult to clearly identify cecum from other overlapping air-filled loops of bowel (Fig 4B). It is important to spend time and care at this stage of the procedure, mapping out with fluoroscopy the anatomy. A safe access route is chosen avoiding the structures mapped and the VP shunt, if present (Fig 4C). Awareness of proximity to the iliac crest or lower costal margin is important to avoid site irritation problems. The cecum is punctured with an 18-G single-wall puncture, 7-cm-long needle (e.g., Merit, Medical, Ireland) preloaded with two pediatric retention sutures (Cope Pediatric Gastrointestinal Suture Anchor set, Cook), and the intraluminal position is confirmed with contrast. The retention sutures are then deployed with a 0.035⬙ Amplatz wire (Fig 5A), and gentle traction is placed on the threads with a light mosquito clamp. Over the wire, the tract is dilated with an 8 Fr. dilator, and then over the wire an 8 Fr. pigtail catheter (MAC-LOC Dawson-Mueller, Cook) is placed (Fig 5B,C). We advance the wire, the dilator, and the pigtail only a short way into the cecal lumen, to avoid having to withdraw too much contaminated wire or tubing back through the tract. The tube is left to free drainage and venting for the following week. The retention sutures are rolled over gauze and B. CONNOLLY
Fig 4. (A) Air-filled cecum clearly identified on AP fluoroscopy, with the access needle prepared to puncture. (B) AP view of the right side of the abdomen with multiple overlapping loops of air-filled bowel. (C) Similar image in another child with a VP shunt seen in the epigastrium (arrows).
secured with tape. The site is dressed with Polysporin and an adhesive dressing. The rectal Foley catheter is removed.
ally adequate, but the latter may result in less effective bowel evacuations.
Postprocedure—Early
Postprocedure—Late
Fluids by mouth can be commenced once bowel sounds return, progressing gradually to diet as tolerated. Our current practice is for a single dose of antibiotics before the procedure. Only if difficulties are encountered during the procedure are triple antibiotics employed for 5 days. The patient is discharged home once eating well, usually after 3 to 5 days. The patient’s usual regimen for washouts is employed after 3 days. Bowel irrigations through the tube are commenced 10 days after C-tube placement. The retention sutures are cut after 14 days. Complications have included placement into a redundant sigmoid loop, ileal placement, peritonitis, VP shunt infection, pelvic abscess, as well as numerous site and tube maintenance problems. Ileal and sigmoid placements of tubes have been function-
After 8 weeks the pigtail catheter is changed to a low-profile device or button, e.g., the “Chait TrapdoorTM” (Pediatric Cecostomy Catheter, Cook) (Fig 6). Due to fecal concretions changing the pigtail for the TrapdoorTM over a straight wire 0.35⬙ is sometimes difficult. Use of a hydrophilic glide wire is often helpful. The TrapdoorsTM come in two lengths to accommodate those patients with a thicker abdominal wall. This is then electively replaced annually. As the spring shape of the Chait Trapdoor TM also stiffens with age and with fecal concretions, it becomes very difficult to remove it. Therefore at annual tube changes, the old tube is not removed. Instead a wire is passed only part way into the old C tube, and the external flap of the old tube is then cut around the wire. The new tube is
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Fig 5. (A) AP fluoroscopic view of an air-filled cecum with two retention sutures deployed and an Amplatz wire inserted a short way (stiff part) into the cecal lumen. (B, C) Cecostomy tube in position with contrast in the colon. Note the confusing collection of air-filled loops and VP shunt (B) and spinal hardware (C).
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B. CONNOLLY
manage, may contain a cartilaginous remnant, and can easily perforate during balloon dilation.38 Contraindications include uncorrectable coagulopathy. Relative contraindications include a very brittle or unsafe airway, when dilation can be attempted from below, if the patient has a G tube.
Sedation Most cases are done as a day case. Informed consent is obtained from the parents, outlining the risks of bleeding, esophageal tear, mediastinitis, aspiration, and recurrence of symptoms/ stricture requiring further dilatations.35,39 Dilations are performed under anesthesia, using either intubation or propofol infusion anesthesia, at the discretion of the anesthetist. In those children with epidermolysis bullosa, great care is needed by the anesthetist to avoid blistering of the face, mouth, or airway.
Technique
Fig 6. Short (left) and long (right) trap door cecostomy tube.
advanced over the wire, in so doing pushing the old tube into the cecal lumen, to be passed per rectum later. Retention of one old tube has occurred on one occasion. Irrigations are usually performed every second day. Each child has a somewhat individual routine. The solution used is a phosphate solution 2-4 ml/Kg, followed by salt–water solution until the bowel irrigation fluid is clear. Signs and symptoms of phosphate excess have been seen and include nausea and vomiting, lethargy, and sweating. A reduction in the dose of phosphate used is then required. Liberal oral fluids on the day of the irrigation are also encouraged.
Esophageal Dilatation Indications and Contraindications Unlike in adults where a malignancy is the commonest cause of esophageal stricture, in neonates and children, the common causes are benign, e.g., caustic ingestion, achalasia, and an anastomotic stricture following tracheoesophageal fistula (TEF) repair33-35 (Fig 7A,B). The latter usually occurs in the upper one-third of the esophagus and may require several balloon dilatations to maintain adequate patency. Other indications for stricture dilation include epidermolysis bullosa strictures,36,37 reflux esophagitis with stricture, and rarely, congenital strictures (Fig 7C). Note the latter is difficult to GASTROINTESTINAL INTERVENTIONS—EMPHASIS ON CHILDREN
Usually esophageal dilation is done through the mouth. If performed through a gastrostomy stoma, temporarily remove the G tube over a wire and advance the wire and the balloon up the esophagus from below. From above, the oropharynx is negotiated using a floppy wire (e.g., 0.035⬙ Bentson) and an angled catheter (e.g., JBI 5 Fr.). The upper esophageal pouch is identified with minimum amount of contrast, avoiding overspill into the airway. As the endotracheal tubes (ET tubes) in children are usually uncuffed, this can easily occur. The length and level of the stricture are identified. Then the wire is advanced down into the stomach and the intragastric position is confirmed. Over the same wire, the catheter is exchanged for a suitably sized balloon e.g., 6, 10, 15 mm, or greater for the patients with achalasia. The size is judged by the child’s native esophagus, below the stricture. A 5- or 6-mm balloon is usually a good initial size in an infant post-TEF repair. The balloon is inflated using one-half strength contrast diluted with water, until the waist is seen; this is then stretched gently until the waist disappears. The inflation may be done by hand or by manometer. The balloon is held inflated for less than 30 seconds, to avoid esophageal mucosal ischemia. A contrast check through the distal end of the catheter is performed at the end of the procedure to evaluate the mural integrity and any possible esophageal tear or leak. The appearance often is not any better on immediate check than predilation. The contrast is aspirated from the upper pouch as best as possible, to avoid reflux and overspill into the airway, remembering the pediatric uncuffed ET tubes. Should aspiration occur, the patient requires active observation and may even require an overnight admission.
Postprocedure—Early The patients are allowed clear fluids that evening and full fluids the following day. Antibiotics are not usually employed. Some centers use steroids for those children with epidermolysis bullosa pre- and postdilation to help prevent blistering and recurrent stricture, although it is not our practice to do so.
Postprocedure—Late Many children require repeated dilatations (few require ⬎4) at varying intervals in time, with a high rate of success (up to 85%).34,40,41 Experience with stenting of the esophagus is very limited in children. Given that most strictures are benign and because of
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Fig 7. (A, B, C) Examples of pediatric esophageal strictures: (A) a mild fixed smooth narrowing due to caustic ingestion, (B) a post TEF anastomotic stricture, and (C) a focal stricture of epidermolysis bullosa.
issues adjusting to the child’s growth, and the expected life span for children, stenting is generally avoided unless all other measures have failed. The role of stenting in children is therefore yet to be determined. Choice of suitably sized stents that are removable for the small child remains an issue.
Other Bowel Dilatations Balloon dilation of other areas of the bowel (duodenal strictures, strictures of the small or large bowel secondary to necrotizing enterocolitis, or surgical anastomoses) are less common.42-46 The basic principles as outlined for esophageal dilation apply. There is increasing difficulty achieving any dilation with increasing distance and tortuosity from the orifice of access (mouth, anus, stoma). With tortuosity it is important to avoid excessive centrifugal pressure on the convexity of the guide wire which causes stretching of the bowel and increases the risk of bowel tear or perforation. This is especially true of the neonate or infant whose tissues are more fragile than an older person’s. A pediatric surgeon should be aware and available when these distal dilatations are performed, should the need for emergency laparotomy be required. The likelihood of success decreases as the distance from the access route increases. As with other intestinal interventions, those with con-
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genital heart disease require antibiotic prophylaxis for GI interventional procedures that can be anticipated to cause bleeding.
Miscellaneous Although not strictly enteric interventions, other abdominal interventions include percutaneous transhepatic cholangiography, percutaneous transhepatic transcholecystic cholangiography, pancreatic pseudocyst drainage, liver and spleen biopsies, as well as drainage of intraabdominal abscesses secondary to appendicitis, Crohn’s Disease, and other inflammatory causes. A full description of these procedures is beyond the scope of this article. Although the techniques may be similar to those in adults, however, the size of needles and tubes employed, the indications and pathologies, and the choice of sedation or anesthesia are usually quite different.
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