MSC - F. Surgery Answers 2025
.pdf
9. Strangulation of hernia. Etiopathogenesis, clinical picture.
Definition
A strangulated hernia is a surgical emergency where herniated contents (typically bowel or omentum) are trapped and blood supply is compromised, leading to ischemia and necrosis. It is the most dangerous complication of hernias.
Epidemiology
Inguinal hernias: Most common (50–58% of strangulations), especially in men (85%).
Femoral and umbilical hernias: More common in women.
Most often occurs in elderly patients.
Pathogenesis (Mechanisms of Strangulation)
Types of Strangulation:
1. Elastic Strangulation:
oSudden rise in intra-abdominal pressure (coughing, straining, lifting).
oHernial orifice stretches → viscera enter sac → orifice contracts → tight constriction.
oAffects mesenteric vessels → rapid ischemia.
2.Fecal Strangulation:
oSeen in older adults.
oDistended adducting loop presses abducting loop against the hernial ring.
oProgresses slower but leads to compression and ischemia.
3.Mixed Strangulation:
oCombination of elastic and fecal mechanisms.
4. Special Types:
oRichter’s Hernia (Parietal Strangulation): Only part of the intestinal wall is strangulated → may not present with obstruction signs.
oRetrograde (W-shaped) Hernia: Two bowel loops inside sac, central loop in abdomen is strangulated, often missed.
oIntra-sac Incarceration: Entrapment occurs inside the sac due to adhesions or fibrous bands.
Pathological Changes
Strangulation sulcus: Groove from constriction ring.
Ischemia and necrosis of the bowel wall.
Hernial fluid (serous or hemorrhagic).
May lead to perforation, peritonitis, or phlegmon of the hernia sac.
Clinical Features
Subjective Symptoms:
Sudden severe pain at hernia site.
Irreducible swelling (previously reducible).
Nausea and vomiting.
Abdominal distension, constipation, no flatus (signs of obstruction).
Late: fecal vomiting, toxic appearance, shock, hyperemia of skin.
Objective Signs:
Tender, tense, non-reducible hernia.
Absent cough impulse.
Percussion: Tympanic (if gas) or dull (if omentum/herniated fluid).
No bowel sounds, absent peristalsis in affected loop.
10. Strangulation of hernia. Clinical picture, tactics and features of surgical treatment.
Clinical Features
Subjective Symptoms:
Sudden severe pain at hernia site.
Irreducible swelling (previously reducible).
Nausea and vomiting.
Abdominal distension, constipation, no flatus (signs of obstruction).
Late: fecal vomiting, toxic appearance, shock, hyperemia of skin.
Objective Signs:
Tender, tense, non-reducible hernia.
Absent cough impulse.
Percussion: Tympanic (if gas) or dull (if omentum/herniated fluid).
No bowel sounds, absent peristalsis in affected loop.
Diagnostic Challenges
Richter’s Hernia: No full obstruction; can be misdiagnosed.
Retrograde Hernia: Abdominal loop is strangulated—hard to detect preop.
"False" Strangulation (Brock’s Hernia): Exudate collects due to intraabdominal inflammation—not true strangulation.
Treatment
Indication: Emergency Surgery – Do not attempt forced reduction (can cause false reduction and missed necrosis).
Surgical Steps:
1.Approach & Exposure
Layered dissection to expose hernial sac.
2.Opening Sac
Drain hernial fluid (may be serous or hemorrhagic).
3.Strangulation Ring Release
Under direct vision, release the constricting ring carefully to avoid damaging bowel.
4.Viability Assessment of the Strangulated Organ
Criteria for viable bowel:
o Pink color
o Glistering serosa
o Peristalsis present
oPulsation in mesenteric arteries
Criteria for non-viability:
oDark, dull, flaccid, no peristalsis
o Absent arterial pulsation
oStrangulation groove and subserosal hematomas
5.Resection (If Needed)
Resect necrotic bowel.
oAdducting loop: 30–40 cm
oAbducting loop: ~10 cm
Perform primary anastomosis or exteriorization (in case of peritonitis).
6.Hernia Repair (Hernioplasty)
Close the hernial defect.
Mesh repair usually avoided in contaminated fields.
7.Post-op Intubation
Intestinal tube may be used to decompress and protect anastomosis.
Complications
Peritonitis
Sepsis
Intestinal perforation
Recurrence if hernia repair is suboptimal
11.Complications of forced hernia reduction.
Complications of Forced and Spontaneous Reduction of Strangulated Hernia
1. Complications of Forced Reduction
Forced (manual) reduction of a strangulated hernia is strongly discouraged due to the risk of:
False (Imaginary) Reduction: The hernia contents may be pushed into the preperitoneal space or another compartment of a multilocular sac, while strangulation persists.
Delayed Diagnosis: Clinician may be misled by apparent reduction, resulting in missed ischemia or necrosis.
Peritonitis and Sepsis: Necrotic bowel left untreated can lead to intraabdominal infection.
Intra-intestinal Bleeding: Resulting from mucosal necrosis.
Surgical Implication: Any history of forced reduction with ongoing abdominal symptoms warrants immediate surgical exploration to assess bowel viability and prevent progression to peritonitis.
2. Spontaneous Reduction of a Strangulated Hernia
Spontaneous reduction refers to the return of hernia contents into the abdominal cavity without manipulation, which may occur during transport, induction of anesthesia, or spontaneously at rest.
Risks include:
Overlooked Necrosis: The reduced bowel may be non-viable and a potential source of intra-abdominal infection or bleeding.
Peritonitis: May develop hours after spontaneous reduction if necrotic bowel is not addressed.
False Security: The absence of a hernia bulge can delay diagnosis.
Surgical Tactics and Management
If signs of peritonitis or bleeding are present:
Immediate midline laparotomy is indicated.
Resection of non-viable bowel to the level of healthy perfused segments.
Thorough inspection of the abdominal cavity.
If no peritoneal signs are present:
Patient should be admitted for close observation (not discharged).
Monitor for fever, increasing abdominal tenderness, or signs of obstruction.
If symptoms develop, proceed with emergency surgery.
If the patient remains stable for 24–48 hours:
Elective hernia repair may be performed after appropriate investigations.
Late Complications of Spontaneous Reduction
Chronic Intestinal Obstruction: Due to adhesions or strictures from prior ischemic injury.
Symptoms include abdominal pain, bloating, altered bowel habits.
12.Rare types of hernia infringement. Retrograde and parietal (Richter) strangulation.
Rare Types of Hernia Strangulation
1.Mechanisms of Strangulation
Elastic Strangulation:
Caused by sudden increase in intra-abdominal pressure (e.g., coughing, straining). The hernial orifice stretches, allowing bowel to enter, then quickly contracts, leading to mesenteric compression and ischemia.
Acute onset, rapid progression to gangrene.
Fecal Strangulation:
Occurs from overdistension of the adducting bowel loop, which compresses the adjacent (abducting) loop at the hernial orifice.
Slower onset, less mesenteric involvement initially.
2.Rare Types of Infringement
A.Richter’s Hernia (Parietal Strangulation)
Only part of the bowel wall (usually antimesenteric border) is trapped.
Most common in femoral hernias, less often in inguinal or obturator hernias.
No signs of classic intestinal obstruction (bowel lumen remains patent).
Symptoms:
o Local tenderness over hernia site
o Mild or no vomiting
o Diarrhea or normal stool passage possible
o Delayed signs → peritonitis or sepsis
Clinical Concern:
Diagnosis is often delayed due to absent obstruction. Surgical exploration may reveal necrotic bowel with normal bowel movements pre-op.
B.Retrograde Strangulation (Maydl’s Hernia)
Involves two loops of bowel in the hernia sac with the connecting loop inside the abdomen, forming a ‘W’ shape.
The intra-abdominal (central) loop becomes strangulated first.
Seen in large inguinal hernias.
Clinical Clues:
Hernial sac may contain viable bowel loops
Signs of intestinal obstruction and tenderness above the hernia site
High risk of missed diagnosis and early generalized peritonitis
Surgical Note:
Always inspect the intra-abdominal segment thoroughly even if the visible bowel in the sac looks healthy.
C.Strangulated Omentocele
Omentum alone becomes strangulated.
Lacks features of obstruction.
Localized pain and swelling; vomiting is minimal or absent.
Delayed onset of gangrene, starts distally.
Can lead to secondary infection (e.g., scrotal abscess in inguinal hernia).
Conclusion
Richter’s and Maydl’s hernias are atypical and prone to delayed diagnosis.
High index of suspicion is needed, especially in femoral hernias or when clinical features don’t match classical obstruction.
Prompt surgical intervention is essential to prevent bowel necrosis and peritonitis.
13.Phlegmon of the hernial sac. Etiopathogenesis, clinical picture, treatment.
Phlegmon of the Hernial Sac
Etiopathogenesis
Occurs due to necrosis of bowel in a strangulated hernia, followed by bacterial infection.
The infection spreads from the hernial sac into surrounding soft tissues and potentially the abdominal wall.
Commonly seen in neglected or delayed strangulated hernias (>3–5 days).
Clinical Features
Local signs:
o Redness, tenderness, and swelling over the hernia site
o Increased size of the hernia
oInduration and possible fluctuation if abscess forms
Systemic signs:
oFever, tachycardia
oFeatures of intestinal obstruction: pain, distension, vomiting, constipation
o Early signs of peritonitis
Diagnosis
Clinical history of prolonged incarceration and local inflammation
Physical signs of infection and intestinal obstruction
X-ray/Imaging: multiple small bowel air-fluid levels, dilated loops
Diagnosis is clinical, imaging supports obstruction or perforation
Surgical Management
Always an emergency surgery. Two-stage approach preferred:
Stage 1: Midline Laparotomy
Reduces the risk of contaminating the peritoneal cavity
Identify and resect non-viable bowel from the abdominal side
Perform primary anastomosis or diverting stoma depending on condition
Suturing of peritoneum around the hernial neck may isolate abscess
Stage 2: Local Hernia Approach
Open the hernial sac externally
Remove purulent contents and necrotic tissue
Avoid dissection of sac from surrounding tissues
No hernia repair (plastic surgery) in presence of infection
Tamponade the cavity and provide drainage
Key Points
Hernia repair is contraindicated in infected field
Aim is infection control and life-saving, not recurrence prevention
Delayed elective hernioplasty can be done after full recovery
14.Irreducible hernia. Etiopathogenesis, clinical picture and treatment. Differential diagnosis of an irreducible and strangulated hernia.
Irreducible Hernia
Definition
An irreducible hernia is a hernia in which the contents cannot be returned to the abdominal cavity, but without signs of strangulation (i.e., no compromise of blood supply).
Etiopathogenesis
Results from chronic hernia with:
o Repeated protrusion and retraction of contents.