5.5
Pyloric obstruction is a type of gastric outlet obstruction that develops when the pylorus, the valve between the stomach and the duodenum, becomes narrowed or blocked, preventing effective gastric emptying.
The causes of pyloric obstruction are broadly classified as non-cancerous or cancerous.
Non-cancerous causes include conditions such as chronic peptic ulcer disease, which may cause scarring and narrowing of the pyloric canal.
Cancerous causes include tumors like gastric or duodenal carcinoma.
As a result of these conditions, gastric contents accumulate and the stomach becomes distended.
Initially, patients may tolerate liquids better than solids, but as the blockage worsens, even fluids begin to accumulate in the stomach.
Vomiting of undigested food is common and can lead to dehydration and electrolyte imbalances, such as hypokalemia, hypochloremia, and metabolic alkalosis.
Pyloric obstruction, also referred to as gastric outlet obstruction, is a condition characterized by narrowing or blockage at the pylorus—the muscular valve regulating the flow of stomach contents into the duodenum. When this passage becomes impaired, the stomach cannot effectively empty its contents into the small intestine. This disruption leads to a range of gastrointestinal symptoms, including early satiety, bloating, epigastric pain, postprandial nausea, persistent vomiting, and unintentional weight loss.
Etiology
The causes of pyloric obstruction are broadly classified as non-cancerous or cancerous.
Non-cancerous causes include:
Cancerous causes include:
Pathophysiology
Pathophysiologically, impaired gastric emptying leads to the retention of ingested material, which progressively distends the stomach. Initially, individuals may better tolerate liquids than solids, but as the obstruction worsens, even fluids may become poorly tolerated. Vomiting becomes frequent and may involve undigested food from previous meals. Over time, the stomach may lose its ability to contract, further exacerbating the stasis.
Complications include dehydration and electrolyte imbalances, such as hypochloremic and hypokalemic metabolic alkalosis, resulting from repeated vomiting. Chronic obstruction can also lead to malnutrition, especially in patients with concurrent malignancy.
Additionally, prolonged retention of gastric contents raises the risk of aspiration pneumonia, particularly in individuals with compromised airway protection. Timely identification of the underlying cause is critical for effective treatment, as management varies significantly between structural and functional etiologies.
Pyloric obstruction is a type of gastric outlet obstruction that develops when the pylorus, the valve between the stomach and the duodenum, becomes narrowed or blocked, preventing effective gastric emptying.
The causes of pyloric obstruction are broadly classified as non-cancerous or cancerous.
Non-cancerous causes include conditions such as chronic peptic ulcer disease, which may cause scarring and narrowing of the pyloric canal.
Cancerous causes include tumors like gastric or duodenal carcinoma.
As a result of these conditions, gastric contents accumulate and the stomach becomes distended.
Initially, patients may tolerate liquids better than solids, but as the blockage worsens, even fluids begin to accumulate in the stomach.
Vomiting of undigested food is common and can lead to dehydration and electrolyte imbalances, such as hypokalemia, hypochloremia, and metabolic alkalosis.
From Chapter 5:
Now Playing
Gastrointestinal System Disorders
184 Views
Gastrointestinal System Disorders
338 Views
Gastrointestinal System Disorders
344 Views
Gastrointestinal System Disorders
397 Views
Gastrointestinal System Disorders
246 Views
Gastrointestinal System Disorders
164 Views
Gastrointestinal System Disorders
232 Views
Gastrointestinal System Disorders
178 Views
Gastrointestinal System Disorders
241 Views
Gastrointestinal System Disorders
198 Views
Gastrointestinal System Disorders
176 Views
Gastrointestinal System Disorders
157 Views
Gastrointestinal System Disorders
261 Views
Gastrointestinal System Disorders
145 Views
Gastrointestinal System Disorders
180 Views
See More