Wilkie’s Syndrome

Wilkie’s Syndrome (Superior Mesenteric Artery Syndrome – SMAS)

Rare Gastro-Vascular Disorder

Characterized By: Compression of the third part of the duodenum between the abdominal aorta and the superior mesenteric artery.
Result: Can lead to bowel obstruction and nonspecific abdominal symptoms.

Etiology

Aortomesenteric Angle: Normally 38-65 degrees.
Cause: Acute reduction in the mesenteric fat pad cushion.
Factors Contributing to Compression: Abnormal gastrointestinal anatomy, spinal surgery, rapid weight loss (anorexia nervosa, malabsorption, cancer), pediatric growth spurts.

Clinical Presentation

Symptoms: Nausea, vomiting, early satiety, postprandial pain.
Challenges in Diagnosis: Overlapping symptoms with various causes of intestinal obstruction (diabetes mellitus, collagen vascular disease, etc.).

Diagnosis

Diagnostic Gold Standard: Enhanced CT scan.
Importance of Suspicion: High index of suspicion in cases of severe weight loss and upper gastrointestinal symptoms.

Treatment Options

Conservative Initial Treatment: Recommended for all patients. Includes adequate nutrition, nasogastric decompression, and postprandial positioning.
Nutritional Support: Enteral and parenteral support may be necessary.
Surgical Intervention: Considered when conservative measures fail. Indications include long-standing weight loss, duodenal dilatation with stasis, and complicating peptic ulcer disease.
Surgical Procedures: Duodenojejunostomy or gastrojejunostomy to bypass the obstruction.

In summary, Wilkie’s Syndrome (SMAS) is a rare gastro-vascular disorder characterized by duodenal compression, leading to bowel obstruction and nonspecific abdominal symptoms. Diagnosis can be challenging due to overlapping symptoms with other conditions, but a high index of suspicion is crucial. Treatment options range from conservative measures to surgical intervention, depending on the patient’s response to initial therapy and the severity of the condition.

Epidemiology

Incidence: Wilkie’s Syndrome (Superior Mesenteric Artery Syndrome – SMAS) is a rare condition with a variable incidence ranging from 0.013% to 0.78% based on radiographic studies.
Prevalence by Gender: It is more prevalent among females.
Age Group: Typically affects patients aged 10 to 39 years.
Challenges in Estimation: The exact incidence of SMAS is not well-established due to its rarity and nonspecific symptoms, which often lead to misdiagnosis or underdiagnosis.

This highlights the rarity and diagnostic challenges associated with SMAS, making it important for healthcare professionals to consider this condition in patients presenting with relevant symptoms.

Etiology

Wilkie’s Syndrome, also known as Superior Mesenteric Artery Syndrome (SMAS), is a rare condition characterized by the compression of the third portion of the duodenum between the abdominal aorta and the superior mesenteric artery (SMA). This compression occurs when the aortomesenteric angle narrows from its normal range of 25° to 60°. The causes and risk factors associated with SMAS include:

Congenital Anomalies: Some individuals may have congenital factors that predispose them to SMAS.
Acquired Factors: These include:
- Significant Weight Loss: Rapid and significant weight loss can lead to a decrease in the mesenteric fat pad, contributing to SMAS.
- Lumbar Hyperlordosis: Abnormal curvature of the lumbar spine can play a role in narrowing the aortomesenteric angle.
- Restorative Proctocolectomy with Ileal-Anal Anastomosis: This surgical procedure has been associated with the development of SMAS.
- Hypermetabolism: Conditions like trauma and burns can lead to hypermetabolism, which may contribute to SMAS.
- Dietary Conditions: Anorexia and other dietary factors can lead to weight loss and increase the risk of SMAS.
- Prolonged Bed Rest: Extended periods of supine bed rest can be a risk factor.
- Surgical Procedures: Certain surgeries, such as left nephrectomy, ileo-anal pouch surgery, and scoliosis surgery, can increase the risk of SMAS.
Risk Factors: Several risk factors increase the likelihood of developing SMAS, including:
- Asthenic Body Composition: Individuals with a lean body composition are at higher risk.
- Kyphosis: Abnormal curvature of the spine in the sagittal plane can be a risk factor.
- Low Body Mass Index (BMI): A low BMI is associated with an increased risk.
- Loss of Body Mass after Surgery: Post-surgical weight loss can contribute to SMAS.
- Use of Body Casts: The use of body casts can lead to compression of the duodenum.
- Rapid Growth: Periods of rapid growth, such as during adolescence, can increase the risk.
- Prolonged Bed Rest: Extended periods of bed rest are a risk factor.

Due to its rarity and nonspecific symptoms, SMAS can be challenging to diagnose. It is crucial for healthcare professionals to maintain a high level of suspicion in cases of severe weight loss and upper gastrointestinal symptoms to ensure timely diagnosis and treatment. Enhanced CT is considered the gold standard diagnostic modality for SMAS. Treatment options include conservative measures such as adequate nutrition and surgical intervention when conservative approaches are ineffective.

Sign and Symptoms

Wilkie’s Syndrome, also known as Superior Mesenteric Artery Syndrome (SMAS), manifests with a wide range of variable and non-specific symptoms. The most frequently reported symptoms include:

Abdominal pain: This is the most common symptom, reported in 92% of cases. The pain can vary in intensity and may be crampy or intermittent.
Nausea and vomiting: These symptoms are a result of the compression of the duodenum and are reported in 77% of cases. Vomiting can sometimes be bilious (green or yellow in color).
Early satiety: Patients with SMAS often experience a feeling of fullness after consuming only a small amount of food.
Postprandial pain: Pain that occurs after eating is a characteristic symptom of SMAS.
Weight loss: Weight loss is reported in 69.2% of cases and can be attributed to symptoms like early satiety and postprandial pain.
Anorexia: Loss of appetite is common and can contribute to weight loss.
Upper abdominal distension and epigastric tenderness: These symptoms can occur due to the obstruction of the duodenum.
Bilious vomiting: Vomiting that is green or yellow in color may indicate the presence of bile.

It’s important to note that the symptoms of Wilkie’s Syndrome can vary greatly from one individual to another and may fluctuate in intensity. They can develop slowly over time or be severely disabling. Due to the non-specific nature of these symptoms, a high degree of clinical suspicion is required for an accurate diagnosis, and diagnostic imaging, such as enhanced CT, is often necessary to confirm the condition.

Diagnosis of Wilkie’s Syndrome

The diagnosis of Wilkie’s Syndrome, also known as Superior Mesenteric Artery Syndrome (SMAS), can be challenging due to its rarity and nonspecific symptoms. Several diagnostic methods can be employed to confirm the condition:

Enhanced CT (Computed Tomography): This is considered the gold standard diagnostic modality for SMAS. It provides detailed cross-sectional images of the abdomen, allowing for the visualization of anatomical structures and the degree of compression of the duodenum. CT scans can show gastric and duodenal dilation, a narrowed aortomesenteric angle, and the anatomical relationship between the aorta and superior mesenteric artery.
Radiographic Studies: Other radiographic studies can also be helpful in confirming the diagnosis. These may include upper gastrointestinal (GI) series and hypotonic duodenography. These tests can provide dynamic images of the gastrointestinal tract, showing the location and extent of the obstruction.

The diagnosis of SMAS is typically based on a combination of clinical presentation and radiologic evidence of obstruction. Key radiologic findings, such as duodenal dilation and a narrowed aortomesenteric angle, are essential for confirming the diagnosis. Given the challenging nature of this condition, a high degree of clinical suspicion is crucial, especially in individuals with severe weight loss and upper gastrointestinal symptoms, to prompt appropriate diagnostic evaluation.

Differential diagnosis for Wilkie’s Syndrome

The differential diagnosis for Wilkie’s Syndrome, or Superior Mesenteric Artery Syndrome (SMAS), includes various conditions that can present with similar symptoms. These conditions often involve gastrointestinal and nutritional issues and can be challenging to distinguish from SMAS. Here are some conditions to consider in the differential diagnosis:

Anorexia Nervosa and Bulimia: Eating disorders like anorexia nervosa and bulimia can lead to significant weight loss and gastrointestinal symptoms, which may overlap with the symptoms of SMAS. In these disorders, individuals often have altered eating patterns and may experience nausea, vomiting, and abdominal pain.
Diabetes Mellitus: Diabetes can lead to a condition called gastroparesis, characterized by delayed gastric emptying. This delayed emptying can result in symptoms similar to SMAS, such as abdominal discomfort, early satiety, and vomiting.
Collagen Vascular Conditions: Conditions like systemic lupus erythematosus and scleroderma, which fall under collagen vascular diseases, can affect the gastrointestinal tract and cause symptoms that mimic SMAS. These conditions may lead to changes in the structure and function of the digestive system.
Chronic Idiopathic Intestinal Pseudoobstruction: This condition is characterized by symptoms of bowel obstruction without a physical blockage. It can result in abdominal pain, bloating, and other gastrointestinal symptoms similar to SMAS.
Mechanical Obstruction: Conditions like peptic ulcer disease or the presence of a duodenal web can physically block the gastrointestinal tract, leading to symptoms that overlap with SMAS.

Given the nonspecific nature of the symptoms associated with Wilkie’s Syndrome and the potential overlap with other conditions, a thorough clinical evaluation and diagnostic workup are essential for accurate diagnosis and appropriate treatment. High clinical suspicion is crucial, especially in individuals with severe weight loss and upper gastrointestinal symptoms, to ensure timely diagnosis and intervention.

Treatment of Wilkie’s Syndrome

The treatment of Wilkie’s Syndrome, or Superior Mesenteric Artery Syndrome (SMAS), involves both conservative and surgical approaches, and the choice of treatment depends on the severity of the condition and the response to initial interventions. Here are the key aspects of treatment for SMAS:

Conservative Therapy: Conservative management is often the initial approach for SMAS and includes the following:
- Gastrointestinal Decompression: This involves measures to relieve pressure on the compressed duodenum. It may include nasogastric or nasojejunal tube placement for decompression.
- Correction of Electrolyte Abnormalities: Addressing any electrolyte imbalances that may have occurred due to vomiting and inadequate nutrient absorption.
- Nutritional Support: Providing adequate nutrition through enteral or parenteral routes to address malnutrition and weight loss. Nutritional support aims to improve the patient’s overall health and nutritional status.
- Postural Changes: Modifying the patient’s position after meals, such as adopting a knee-to-chest position, to potentially alleviate the compression of the duodenum.
Surgical Intervention: If conservative measures fail to provide relief from symptoms or if the condition is severe, surgical intervention may be necessary. The primary surgical procedure for SMAS is duodenojejunostomy, which involves creating a bypass between the duodenum and jejunum to bypass the compressed section of the duodenum.
- Duodenojejunostomy: This procedure can be performed as an open surgery or laparoscopically. It has a high success rate and is considered the surgical treatment of choice for SMAS.
- Minimally Invasive Approaches: In some cases, minimally invasive techniques like laparoscopic duodenojejunostomy or single-incision laparoscopic procedures may be considered.
- Other Surgical Options: Alternative surgical options include gastrojejunostomy and division of the ligament of Treitz with duodenal mobilization. The choice of procedure depends on the specific case and the surgeon’s expertise.
Nutritional Support: In cases where the patient’s nutritional status remains compromised, non-surgical options such as endoscopy-assisted jejunal feeding tube placement may be considered. This can help improve nutrition and reduce the risk of complications.

The choice of treatment should be individualized based on the patient’s condition, the severity of symptoms, and the response to conservative therapy. Close collaboration between the healthcare team, including gastroenterologists and surgeons, is essential to determine the most appropriate treatment plan for each patient with SMAS.

Prognosis

The prognosis for Wilkie’s Syndrome, or Superior Mesenteric Artery Syndrome (SMAS), is generally favorable when appropriate treatment is provided. Here are key points regarding the prognosis of SMAS:

Conservative Management: Many cases of SMAS respond well to conservative management, which includes measures like nutritional support, postural changes, and correction of electrolyte abnormalities. Conservative treatment can be effective in relieving symptoms and improving the patient’s nutritional status.
Surgical Intervention: When conservative measures fail to alleviate symptoms, surgical intervention, such as duodenojejunostomy, has a high success rate, with reported success rates of approximately 90%. This surgical procedure can effectively bypass the compressed portion of the duodenum, providing relief from the obstruction.
Complications: If left untreated, SMAS can lead to significant morbidity and mortality. Complications may include malnutrition, dehydration, electrolyte imbalances, gastric pneumatosis (presence of gas in the gastric wall), and portal venous gas (presence of gas in the portal vein). Therefore, early diagnosis and treatment are crucial to prevent these complications.
Psychological Impact: SMAS can have a psychological impact on patients. The persistence of symptoms can lead to anxiety and depressive disorders. Additionally, some patients may have been previously misdiagnosed with an eating disorder, which can further contribute to psychological distress and delay the correct diagnosis and treatment.
Recovery: With the correct diagnosis and initiation of appropriate treatment, patients with SMAS can experience a complete recovery. This emphasizes the importance of accurate and timely diagnosis to provide relief from symptoms and improve the patient’s overall well-being.

In summary, SMAS has a favorable prognosis when diagnosed and treated promptly and accurately. Conservative management and surgical intervention have been successful in alleviating symptoms and improving the quality of life for patients with SMAS. Early intervention is essential to prevent complications and address the psychological impact of the condition.