Contents Show
What is pyloric stenosisPyloric stenosis (also called hypertrophic pyloric stenosis) is an uncommon condition in infants where there is a narrowing of the pylorus, the opening from the stomach into the small intestine (duodenum) that blocks food from entering the small intestine. Normally, a muscular valve (pylorus) between the stomach and small intestine holds food in the stomach until it is ready for the next stage in the digestive process (see Figures 1 and 2). In pyloric stenosis, the pylorus muscles thicken and become abnormally large, blocking food from reaching the small intestine (Figures 3 and 4). The exact cause of the thickening is unknown. Genes may play a role, since children of parents who had pyloric stenosis are more likely to have this condition. Other risk factors include certain antibiotics, too much acid in the first part of the small intestine (duodenum), and certain diseases a baby is born with, such as diabetes. Pyloric stenosis occurs most often in infants younger than 6 months. It is more common in boys than in girls. Pyloric stenosis is relatively common and has a male predilection (male:female ratio of ~4:1), and is more commonly seen in Caucasians 1). While symptoms may start as early as 3 to 5 weeks after birth, it typically occurs between the 6 to 12 weeks of age. First born children are at higher risk and there may be a positive family history in some cases. If a parent had pyloric stenosis, then a baby has up to a 20% risk of developing it. Incidence of hypertrophic pyloric stenosis is approximately 2-5 per 1,000 births per year in most white populations in United States. Hypertrophic pyloric stenosis is less common in India and among black and other Asian populations. Clinical presentation of pyloric stenosis is typical with non-bilious projectile vomiting. Pyloric stenosis can lead to dehydration and weight loss. Babies with pyloric stenosis may seem to be hungry all the time. The hypertrophied pylorus can be palpated as an olive-sized mass in the right upper quadrant. A succussion splash may be audible, and although common, is only relevant if heard hours after the last meal 2). Surgery cures pyloric stenosis. When to see a doctor See your baby’s doctor if your baby:
Figure 1. Stomach Figure 2. Pylorus of the stomach Figure 3. Hypertrophic pyloric stenosis – in pyloric stenosis, the pylorus muscles thicken, blocking food from entering the baby’s small intestine. Figure 4. Pyloric stenosis ultrasound Note: Abdominal ultrasound shows an elongated pyloric canal with increased pyloric muscle thickness. Redundant pyloric mucosa is seen projecting into the gastric antrum on longitudinal image (antral nipple). Pyloric stenosis in adultsIdiopathic hypertrophic pyloric stenosis, in adults, is a rare disease 3). Pyloric stenosis in adults is a rare disease and presents in adult life as pyloric obstruction, without a history of vomiting in infancy or other gastrointestinal symptoms. Abdominal distention relieved by vomiting is usually the only physical sign. All patients experience weight loss 4). Diagnosis is made with barium contrast upper gastrointestinal series and upper endoscopy 5). Malignancy has to be ruled out. Optimal treatment should provide relief of obstruction, low recurrence and low operative morbidity, since adult idiopathic hypertrophic pyloric stenosis is a benign disease. Pyloromyotomy, pyloroplasty, gastrojejunostomy, endoscopic dilatation and gastrectomy have all been recommended for adult idiopathic hypertrophic pyloric stenosis 6). Adult hypertrophic pyloric stenosis is classified into three types 7):
Diagnosis is based upon history, clinical and radiological findings and endoscopic appearance. The main symptom in every patient is postprandial upper abdominal distension. The discomfort is relieved by vomiting. Nausea and pain are minimal during vomiting. Anorexia and early satiety can be present. All patients experience weight loss. The absence of pain at the onset of symptoms is a significant diagnostic point. The duration of symptoms can range from 5 weeks to 16 years 9). Several radiological signs have been described related to adult idiopathic hypertrophic pyloric stenosis. The length of a normal pyloric canal is no more than 1 cm. In adult idiopathic hypertrophic pyloric stenosis, the length may extend up to 4 cm. A convex indentation at the base of the duodenal bulb, known as Kirklin’s sign, is another indication of adult idiopathic hypertrophic pyloric stenosis. An eccentric or concentric narrowing of the pyloric region is the “string sign.” The “Twining’s” sign is a barium filling defect, which can project to either or both sides of the pylorus. It is located 4 to 6 cm proximal to the base of the duodenal bulb 10). Some or all these findings can distinguish adult idiopathic hypertrophic pyloric stenosis from other diseases. In contrast, there are reports that “typical” cases are rare, and the radiological picture is highly variable. Some patients with adult idiopathic hypertrophic pyloric stenosis have repeatedly normal radiographs. In addition, patients with pyloric carcinoma have had x-rays similar to those seen in adult idiopathic hypertrophic pyloric stenosis 11). Endoscopically, the pylorus is fixed, markedly narrow and has a smooth border. Its appearance has been described as the “cervix sign,” or even as a “donut.” The pylorus fails to close completely even though the peristaltic waves appear to culminate in some degree of contraction in the pyloric area. The main advantage of endoscopy is that it can easily differentiate adult idiopathic hypertrophic pyloric stenosis from other diseases that cause gastric outlet obstruction 12). Biopsy should always be taken to exclude malignancy 13). Surgical exploration has been advised to establish diagnosis and provide treatment. Gastrectomy, gastrojejunostomy, pyloromyotomy and pyloroplasty have been recommended for adult idiopathic hypertrophic pyloric stenosis. Full-thickness biopsy is proposed for the exclusion of malignancy 14). Most reports in the literature have advocated subtotal distal gastric resection. Pyloromyotomy is undesirable because of possible mucosal laceration and late diverticula. Pyloroplasty is considered technically difficult if the pylorus is grossly thickened and is reserved for the debilitated patient 15). Brahos and Meck have performed a double pyloroplasty in one patient. The closure was completed without tension, and a wide pyloric channel was produced 16). The benign nature of the disease prompted Levine et al 17) to suggest non-operative diagnosis and treatment. The authors have concluded that laparotomy is not required for the diagnosis and that gastroscopic findings are more important than radiographic findings. Dye et al treated a poor operative candidate with endoscopic dilatation. Examination with barium on the following day showed only a slightly wider pyloric channel. The patient subsequently was placed on a solid diet but had occasional vomiting 18). Endoscopic balloon dilatation performed for benign pyloric stenosis from other causes resulted in a high recurrent obstruction rate. In two separate studies, the authors suggested that endoscopic dilatation may palliate symptoms but should be reserved only for patients with high operative risk 19). The patient we are presenting had only temporary relief after two balloon dilatations. The benign nature of the disease in adults mandates a surgical treatment that can be performed safely and effectively with low morbidity and mortality rate. It is reasonable to relieve the pyloric obstruction as directly and atraumatically as possible. A major operation like gastric resection seems unnecessary for a benign process. The diagnosis can be performed more safely with endoscopy, and pyloroplasty has less morbidity than gastrectomy. Laparoscopic pyloroplasty is a technically feasible operation requiring laparoscopic suturing skills. It can be safely performed in adult idiopathic hypertrophic pyloric stenosis. It provides treatment while preserving the benefits of a minimally invasive surgical technique in the debilitated patient. Laparoscopic pyloroplasty is safe, effective and offers decreased pain, hospital stay and postoperative disability. Larger studies and longer follow-up are required for its establishment as the treatment of choice. Pyloric stenosis long term effectsPyloric stenosis can lead to:
Pyloric stenosis outlook (prognosis)Surgery usually relieves all symptoms. As soon as several hours after surgery, the infant can start small, frequent feedings. Pyloric stenosis causesThe causes of pyloric stenosis are unknown, but genetic and environmental factors might play a role. Pyloric stenosis usually isn’t present at birth and probably develops afterward. Hypertrophic pyloric stenosis is the result of both hyperplasia and hypertrophy of the pyloric circular muscles fibers. The pathogenesis of this is not understood. There are four main theories 20):
Risk factors for pyloric stenosisRisk factors for pyloric stenosis include:
Pyloric stenosis symptomsSigns of pyloric stenosis usually appear within three to five weeks after birth. Pyloric stenosis is rare in babies older than age 3 months. Signs and symptoms include:
Other symptoms may include:
Other conditions can cause similar problems. For instance:
Pyloric stenosis diagnosisThe condition is usually diagnosed before the baby is 6 months old. Your baby’s doctor will start with a physical examination. Sometimes, the doctor can feel an olive-shaped lump — the enlarged pyloric muscle — when examining the baby’s abdomen. The peristaltic waves in the baby’s abdomen are another telltale sign of pyloric stenosis. A physical exam may reveal:
Your doctor might also recommend:
Plain radiograph Abdominal x-ray findings are non-specific but may show a distended stomach with minimal distal intestinal bowel gas. Fluoroscopy An upper gastrointestinal series (barium meal) excludes other, more serious causes of pathology, but the findings of a upper gastrointestinal series infer rather than directly visualize the hypertrophied muscle. On upper gastrointestinal fluoroscopy:
Ultrasound Ultrasound is the modality of choice in the right clinical setting because of its advantages over a barium meal are that it directly visualises the pyloric muscle and does not use ionising radiation. Unfortunately, it is incapable of excluding other diagnoses such as midgut volvulus. Easy ultrasound technique is to find gallbladder then turn the probe obliquely sagittal to the body in an attempt to find pylorus longitudinally. The hypertrophied muscle is hypoechoic, and the central mucosa is hyperechoic. Diagnostic measurements include (mnemonic “number pi”):
With the patient right side down the pylorus should be watched and should not be seen to open. Described sonographic signs include:
Pyloric stenosis treatmentInitial medical management is essential with rehydration and correction of electrolyte imbalances. This should be completed prior to surgical intervention. Treatment is surgical with a pyloromyotomy in which the pyloric muscle is divided down to the submucosa. This can be performed both open and laparoscopically. The operation is curative and has very low morbidity 21). Pyloric stenosis surgerySurgery is needed to treat pyloric stenosis. The procedure (pyloromyotomy) is often scheduled on the same day as the diagnosis. If your baby is dehydrated or has an electrolyte imbalance, he or she will have fluid replacement before surgery. In pyloromyotomy, the surgeon cuts only through the outside layer of the thickened pylorus muscle, allowing the inner lining to bulge out. This opens a channel for food to pass through to the small intestine. Pyloromyotomy is often done using minimally invasive surgery. A slender viewing instrument (laparoscope) is inserted through a small incision near the baby’s navel. Recovery from a laparoscopic procedure is usually quicker than recovery from traditional surgery, and the procedure leaves a smaller scar. Figure 5. Pyloric stenosis surgery (Pyloromyotomy) After pyloric stenosis surgery:
Most babies return to normal feedings fairly quickly, usually 3 to 4 hours after the surgery. Because of swelling at the surgery site, a baby may still vomit small amounts for a day or so. If there are no complications, most babies who have had pyloromyotomy can return to a normal feeding schedule and go home within 24 to 48 hours of the surgery. If you’re breastfeeding, you might worry about continuing while your baby is hospitalized. The hospital staff should be able to provide a breast pump and help you use it so that you can continue to express milk until your baby can feed regularly. After a successful pyloromyotomy, your baby won’t need to follow any special feeding schedules. Your doctor will probably want to examine your child at a follow-up appointment to make sure the surgical site is healing properly and that your baby is feeding well and maintaining or gaining weight. Pyloric stenosis should not happen again after a pyloromyotomy. If your baby still has symptoms weeks after the surgery, there might be another medical problem, such as gastritis or gastroesophageal reflux, so let your doctor know right away. Potential complications from pyloric stenosis surgery include bleeding and infection. However, complications aren’t common, and the results of surgery are generally excellent. References [ + ] What happens if pyloric stenosis is left untreated?If left untreated, hypertrophic pyloric stenosis can cause: Dehydration. Electrolyte imbalance. Lethargy.
What is the most common symptom in a child with pyloric stenosis?The most common symptoms noted in a baby with pyloric stenosis is forceful, projectile vomiting. This kind of vomiting is different from a "wet burp" that a baby may have at the end of a feeding. Large amounts of breast milk or formula are vomited, and may go several feet across a room.
What organs are affected by pyloric stenosis?Pyloric stenosis is the narrowing of the lower portion of the stomach (pylorus) that leads into the small intestine. The muscles in this part of the stomach thicken, narrowing the opening of the pylorus and preventing food from moving from the stomach to the intestine.
What is the prognosis of pyloric stenosis?In general, patients who receive surgical treatment for pyloric stenosis have an excellent recovery and very few suffer any long-term problems as a result of the disease. After surgery, your baby may be fed special fluids for one or two feedings and then breast milk or formula within 24 hours.
|