Stomach Bed

Structures Forming the Stomach Bed

• Sleisenger and Fordtran's GI and Liver Disease: "The anterior surface of the body [of pancreas] is covered by peritoneum of the omental bursa, which separates the stomach from the pancreas. The antrum and body of the stomach and the transverse mesocolon contact the body anteriorly."

Key Points

Clinical Relevance

1. Posterior gastric ulcer perforation: A posterior gastric ulcer can perforate into the lesser sac and erode into the structures of the stomach bed, most classically the splenic artery (causing massive hemorrhage) or the pancreas (causing pancreatitis/fistula).
2. Carcinoma of the stomach (posterior wall): Spread posteriorly can involve the pancreas, left kidney, adrenal, or splenic vessels - making surgical resection difficult or impossible.
3. Pancreatic pseudocyst: Can bulge anteriorly into the lesser sac between the stomach and the stomach bed, and is seen just posterior to the stomach on imaging. As noted in Schwartz's Principles of Surgery: "Once the gastrocolic omentum is divided, the body and tail of the pancreas can be seen along the floor of the lesser sac, just posterior to the stomach."
4. Splenic surgery and left kidney exposure: Surgeons approach the left kidney and adrenal gland through the stomach bed by entering the lesser sac.

Summary Mnemonic - "DSAKPT"

• D - Diaphragm (left crus and dome)
• S - Spleen (left end)
• A - Adrenal (left suprarenal gland)
• K - Kidney (upper left)
• P - Pancreas (body and tail)
• T - Transverse mesocolon (and splenic artery along pancreatic upper border)

Sources: Gray's Anatomy for Students; Color Atlas of Human Anatomy Vol. 2, Internal Organs; Sleisenger and Fordtran's GI and Liver Disease; Schwartz's Principles of Surgery, 11e

1. Prostate Cancer - Brain Metastasis

Overview

Routes of Metastasis

• Brain is the most common intracranial site of metastases generally
• Prostate cancer has a particular predilection for the dura (dural metastases), and may be the only site of metastasis in otherwise well-treated patients
• Goldman-Cecil Medicine: "Dural metastases most commonly arise from breast or prostate cancer, frequently from a metastasis."
• Plum and Posner's Stupor and Coma: "Breast and prostate cancer and M4-type acute myelomonocytic leukemia have a particular predilection for the dura."

Key Clinical Points

2. Meckel's Diverticulum

Definition

Rule of 2s (Classic Mnemonic)

• 2% of the population
• 2 inches (~5 cm) long
• 2 feet (~60 cm) from the ileocaecal valve
• 2 types of ectopic mucosa (gastric most common, pancreatic)
• 2 times more symptomatic in males
• 2 years - most present before age 2

Complications (from Bailey and Love's and S Das)

Surgical Rule

• Wide-mouthed, non-thickened incidental Meckel's = can leave alone
• Symptomatic or narrow-necked = diverticulectomy or segmental ileal resection (for bleeding, as the ulcer is usually adjacent to the diverticulum, not inside it)

3. Haemorrhoids (Piles)

Definition

Anatomy

• Internal haemorrhoids: above the dentate line; covered by mucosa; arise from the internal haemorrhoidal (superior rectal) plexus
• External haemorrhoids: below the dentate line; covered by squamous skin; arise from the inferior haemorrhoidal plexus
• Classic positions: 3, 7, and 11 o'clock (patient in lithotomy position) = right anterior, right posterior, left lateral

Pathophysiology

• Upright posture + no venous valves in the portal system + raised intra-abdominal pressure (straining, pregnancy) → venous congestion
• Shearing forces → mucosal trauma (bleeding) and caudal displacement (prolapse)

Degrees of Internal Haemorrhoids

Symptoms

• Bright red, painless bleeding (on paper or splash in pan)
• Pruritus (from mucus discharge)
• Pain = suggests another diagnosis (fissure, thrombosed external haemorrhoid)
• Mucus discharge, prolapse

Treatment

• 1st/2nd degree: dietary advice, rubber band ligation, sclerotherapy
• 3rd/4th degree: haemorrhoidectomy (Milligan-Morgan)

4. Varicocele

Definition

Anatomy of the Pampiniform Plexus

Epidemiology & Laterality

• 90% left-sided (due to the right-angle drainage of the left testicular vein into the left renal vein vs. the oblique drainage of the right testicular vein into the IVC)
• Also: angulation at the left testicular vein-renal vein junction, greater hydrostatic pressure on the left
• Isolated right-sided varicocele = red flag - must exclude retroperitoneal mass or renal tumour (right testicular vein drains at an acute angle to the IVC; right-sided obstruction suggests extrinsic compression)

Clinical Features

• Dragging discomfort in the scrotum, worse at end of day / when standing
• On examination (standing): "bag of worms" feel on palpation
• Varicocele decompresses when lying down (distinguishes from secondary obstruction)
• Long-standing cases: testicular atrophy and reduced sperm quality

Grading (Clinical)

• Grade I: palpable only on Valsalva
• Grade II: palpable without Valsalva
• Grade III: visible through scrotal skin

Secondary Varicocele

• Left renal cell carcinoma compressing the left renal vein → left testicular vein obstruction
• Does NOT decompress on lying down

Treatment

• Surgical ligation (inguinal/subinguinal/retroperitoneal approach)
• Radiological embolization via right femoral → IVC → left renal vein → left testicular vein

5. Omphalocele vs. Umbilical Hernia

Omphalocele (Exomphalos)

• Covered by a sac of fused amnion + peritoneum (avascular)
• Umbilical cord inserts into the apex of the sac
• Abdominal wall musculature is intact around the defect
• Large omphaloceles contain liver and spleen outside the cavity
• Associated anomalies in ~50-75% of cases:
  • Beckwith-Wiedemann syndrome (gigantism, macroglossia, umbilical defect, hypoglycemia)
  • Chromosomal anomalies (trisomies 13, 15, 18, 21)
  • OEIS complex (Omphalocele, Exstrophy, Imperforate anus, Spinal defects)
  • Cardiac defects, pentalogy of Cantrell

Umbilical Hernia

6. Faecal Fistula

Definition

Types

1. Faecal fistula from large bowel - may develop due to leakage from a suture line or anastomosis
2. Umbilical faecal fistula - due to a patent vitello-intestinal (omphalomesenteric) duct (the same duct remnant as Meckel's diverticulum); presents as faecal discharge from the umbilicus
3. Gastrocolic fistula - communication between stomach and colon; causes faeculent vomiting
4. Enterovaginal / enterovesical fistula - bowel to vagina or bladder

Causes

• Post-operative anastomotic leak (most common in surgical practice)
• Crohn's disease
• Diverticular disease
• Radiation enteritis
• Malignancy
• Trauma
• Patent vitello-intestinal duct (congenital)

Management (Intestinal Fistula)

• Conservative: NBM + NG drainage + IV nutrition (TPN) + fluid/electrolyte replacement; may take weeks to seal
• Contrast studies to identify the fistula level and check for distal obstruction
• If conservative fails or there is distal obstruction: surgical resection of fistulated segment
• Small bowel fistulae are more serious (loss of digestive enzymes causes skin excoriation and significant fluid/electrolyte losses)

7. Cremasteric Reflex

Definition

Reflex Arc

Clinical Significance

1. Testicular Torsion: Absence of the cremasteric reflex on the affected side is a key clinical sign. Campbell Walsh Urology: "The most common physical findings are generalized testicular tenderness, abnormal orientation of the testis, and absent cremasteric reflex." However, a present cremasteric reflex does NOT rule out torsion (sensitivity 73-96%).
2. Spinal cord assessment: Tests the integrity of the L1-L2 spinal segment. Absent in L2 lesions.
3. Age-related variation: More active in children; tends to diminish with age; may be absent in certain neurological disorders.
4. Genitofemoral nerve injury: e.g., during inguinal hernia repair - can abolish the cremasteric reflex on the ipsilateral side.

Sources: Bailey and Love's Short Practice of Surgery, 28e; Gray's Anatomy for Students; S Das - A Manual on Clinical Surgery, 13e; Campbell-Walsh-Wein Urology; Harrison's Principles of Internal Medicine, 22e; Goldman-Cecil Medicine; Sleisenger and Fordtran's GI and Liver Disease; Localization in Clinical Neurology, 8e; Developing Human - Clinically Oriented Embryology