INTERNAL HERNIASINTERNAL HERNIASWHAT YOU MUST KNOWWHAT YOU MUST KNOW

Richard M. Gore, MDNorthShore University Health System

University of ChicagoEvanston, IL

SCBT/MR 2010San Diego, California

March 8, 201015:40-15:50

OBJECTIVESOBJECTIVES

•• Emphasize the clinical importance and Emphasize the clinical importance and prevelance of internal herniasprevelance of internal hernias

•• Review the types of internal herniasReview the types of internal hernias•• Describe the clinical and imaging features Describe the clinical and imaging features

of these herniasof these hernias

INTERNAL HERNIASINTERNAL HERNIAS

•• Protrusion of the gut through the Protrusion of the gut through the peritoneum, mesentery, or omentum into a peritoneum, mesentery, or omentum into a compartment in the abdominal cavitycompartment in the abdominal cavity

•• The hernia orifice is usually a preexisting The hernia orifice is usually a preexisting foramen, recess, and fossa but can be foramen, recess, and fossa but can be caused by surgery, ischemia, and traumacaused by surgery, ischemia, and trauma

INTERNAL HERNIASINTERNAL HERNIAS

•• Congenital defects are anomalies of Congenital defects are anomalies of intestinal rotation and mesenteric intestinal rotation and mesenteric attachmentsattachments

•• Autopsy incidence 0.2 Autopsy incidence 0.2 -- 0.9%0.9%

WHY INTERNAL HERNIAS WHY INTERNAL HERNIAS ARE IMPORTANTARE IMPORTANT

•• IH should be a major default diagnosis in IH should be a major default diagnosis in patients with SBO, especially with closed patients with SBO, especially with closed loop or strangulating featuresloop or strangulating features

•• Contributor to tsunami of requests for Contributor to tsunami of requests for outpatient abdominal CT scans for outpatient abdominal CT scans for abdominal discomfort and painabdominal discomfort and pain

•• Source of chronic and intermittent bowel Source of chronic and intermittent bowel obstrutionobstrution

CAUSES OF SMALLCAUSES OF SMALLBOWEL OBSTRUCTION BOWEL OBSTRUCTION

•• ADHESIONS 49%ADHESIONS 49%•• HERNIAS 30%HERNIAS 30%•• NEOPLASMS 15%NEOPLASMS 15%•• OTHER 6%OTHER 6%

HERNIAS AS CAUSE OFHERNIAS AS CAUSE OFBOWEL OBSTRUCTION BOWEL OBSTRUCTION

•• INTERNAL HERNIASINTERNAL HERNIAS 33%33%•• EXTERNAL HERNIASEXTERNAL HERNIAS 66%66%

HERNIAS AS CAUSE OFHERNIAS AS CAUSE OFSTANGULATION STANGULATION

•• INTERNAL HERNIASINTERNAL HERNIAS 40%40%•• EXTERNAL HERNIASEXTERNAL HERNIAS 60%60%

INTERNAL HERNIASINTERNAL HERNIAS

•• Preoperative diagnosis can be difficult: S+S Preoperative diagnosis can be difficult: S+S range from high grade bowel obstruction to range from high grade bowel obstruction to mild digestive complaintsmild digestive complaints

•• If reducible they are often silentIf reducible they are often silent•• IH are the most common cause of strangIH are the most common cause of strang--

ulating obstructionulating obstruction

INTERNAL HERNIASINTERNAL HERNIAS

•• During the past decade the incidence of IH During the past decade the incidence of IH has increased due to more frequent has increased due to more frequent bariatric surgery and liver transplantationbariatric surgery and liver transplantation

•• RYGB is associated with an increased RYGB is associated with an increased incidence of transmesenteric, incidence of transmesenteric, transmesocolic and retroanastomotic transmesocolic and retroanastomotic internal herniasinternal hernias

TYPES OFTYPES OFINTERNAL HERNIASINTERNAL HERNIAS

•• Broad ligamentBroad ligament•• Fossa of DouglasFossa of Douglas•• Perirectal fossaPerirectal fossa

Radiographics 25: 997Radiographics 25: 997--1015, 20051015, 2005

TYPES OFTYPES OFINTERNAL HERNIASINTERNAL HERNIAS

•• Left paraduodenalLeft paraduodenal•• Right paraduodenalRight paraduodenal•• PericecalPericecal•• Foramen of WinslowForamen of Winslow•• TransomentalTransomental•• IntersigmoidIntersigmoid•• TransmesentericTransmesenteric•• RetroanastomoticRetroanastomotic

Radiographics 25: 997Radiographics 25: 997--1015, 20051015, 2005

INTERNAL HERNIASINTERNAL HERNIAS

•• Paraduodenal Paraduodenal 53%53%•• Pericecal Pericecal 13%13%•• Foramen of WinslowForamen of Winslow 8%8%•• TransmesentericTransmesenteric 8%8%•• IntersigmoidIntersigmoid 6%6%•• SupravesicalSupravesical--pelvicpelvic 6%6%•• TransomentalTransomental 11--4%4%

PARADUODENAL HERNIASPARADUODENAL HERNIAS

•• Paraduodenal fossae originate as Paraduodenal fossae originate as congenital peritoneal anomalies due to congenital peritoneal anomalies due to failure of mesenteric fusion with the parietal failure of mesenteric fusion with the parietal peritoneum and an associated abnormal peritoneum and an associated abnormal rotation as the SB is imprisoned beneath rotation as the SB is imprisoned beneath the developing colonthe developing colon

INTERNAL HERNIAS: AIDS ININTERNAL HERNIAS: AIDS INPREOPERATIVE DIAGNOSISPREOPERATIVE DIAGNOSIS

•• Engorged, stretched, and displaced mesenteric Engorged, stretched, and displaced mesenteric vascular pedicle and convergence of vessels at the vascular pedicle and convergence of vessels at the hernia orificehernia orifice

•• Saclike mass or cluster of dilated SB loops at an Saclike mass or cluster of dilated SB loops at an abnormal anatomic location in the setting of SBOabnormal anatomic location in the setting of SBO

•• Knowledge of the normal anatomy of the peritoneal Knowledge of the normal anatomy of the peritoneal cavity and characteristic anatomic locationcavity and characteristic anatomic location

PARADUODENALPARADUODENALFOSSAEFOSSAE

•• Superior duodenal Superior duodenal fossafossa

•• Inferior duodenal Inferior duodenal fossa (Treitz)fossa (Treitz)

•• Paraduodenal fossa Paraduodenal fossa (Landzert)(Landzert)

•• Intermesocolic Intermesocolic (Broesike)(Broesike)

•• Mesentericoparietal Mesentericoparietal (Waldeyer)(Waldeyer)

PARADUODENALPARADUODENALFOSSAEFOSSAE

•• Paraduodenal fossa (Landzert) found in 2% Paraduodenal fossa (Landzert) found in 2% of autopsiesof autopsies-- induces left PDHinduces left PDH

•• Mesentericoparietal (Waldeyer) found in 1% Mesentericoparietal (Waldeyer) found in 1% ofautopsiesofautopsies-- induces right PDHinduces right PDH

PERICECAL HERNIAPERICECAL HERNIA

•• 4 pericecal 4 pericecal recesses can be recesses can be involved with involved with hernias: retrocecal, hernias: retrocecal, paracolic, superior paracolic, superior ileocecal, inferior ileocecal, inferior ileocecalileocecal

•• 13% of all internal 13% of all internal herniashernias

AJR 186: 703AJR 186: 703--717, 2006717, 2006

PERICECAL HERNIAPERICECAL HERNIA

•• Ileal loops occupy the right paracolic gutterIleal loops occupy the right paracolic gutter•• Clustering of fluid filled SB lateral to the cecum and Clustering of fluid filled SB lateral to the cecum and

posterior to the ascending colonposterior to the ascending colon•• Tethering at the aperture of the peritoneal recess Tethering at the aperture of the peritoneal recess

and dilation of SB with a transition zoneand dilation of SB with a transition zone•• Patients may present with acute abdomenPatients may present with acute abdomen•• Chronic incarceration may be difficult to Chronic incarceration may be difficult to

differentiate from IBD, appendiceal disorders and differentiate from IBD, appendiceal disorders and other causes of SBOother causes of SBO

SIGMOID MESOCOLON SIGMOID MESOCOLON HERNIAHERNIA

•• The intersigmoid fossa lies The intersigmoid fossa lies behind the apex of the Vbehind the apex of the V--shaped parietal shaped parietal attachment of the sigmoid attachment of the sigmoid mesocolonmesocolon

•• This pocket is found in This pocket is found in 65% of autopsies 65% of autopsies

•• Accounts of 6% of all Accounts of 6% of all internal herniasinternal hernias

•• Three types: intersigmoid; Three types: intersigmoid; transmesotransmeso--sigmoid; sigmoid; intermesosigmoidintermesosigmoid

AJR 186: 703AJR 186: 703--717, 2006717, 2006

SIGMOID MESOCOLONSIGMOID MESOCOLON

•• CONTAINS THE SIGMOID CONTAINS THE SIGMOID AND HEMORRHOIDAL AND HEMORRHOIDAL VESSELS OF THE IMA AND VESSELS OF THE IMA AND IMVIMV

•• CONTINUOUS WITH THE CONTINUOUS WITH THE BARE AREA OF COLON BARE AREA OF COLON AND RECTUM, AND AND RECTUM, AND BROAD LIGAMENTBROAD LIGAMENT

•• CONFINES THE SPREAD CONFINES THE SPREAD OF DIVERTICULITISOF DIVERTICULITIS

•• PATHWAY OF DISEASE PATHWAY OF DISEASE SPREAD BETWEEN SPREAD BETWEEN SIGMOID AND OVARYSIGMOID AND OVARY

TRANSOMENTAL HERNIATRANSOMENTAL HERNIA

•• Accounts for 1% Accounts for 1% -- 4% of all internal hernias4% of all internal hernias•• Type IType I-- through the free edge of the GOthrough the free edge of the GO•• Type IIType II-- through the GCL into the lesser sacthrough the GCL into the lesser sac

TRANSOMENTAL HERNIATRANSOMENTAL HERNIA

•• Type IType I-- most common, through a slit like most common, through a slit like opening (2opening (2--10 cm in diameter) at the 10 cm in diameter) at the periphery of the free edge of the GOperiphery of the free edge of the GO

•• SB, cecum, and sigmoid may be involvedSB, cecum, and sigmoid may be involved•• Clinical and radiologic features are almost Clinical and radiologic features are almost

identical to transmesenteric herniasidentical to transmesenteric hernias

TRANSMESENTERIC HERNIATRANSMESENTERIC HERNIA

•• In adults most mesenteric defects are the In adults most mesenteric defects are the result of surgery, trauma, or inflammationresult of surgery, trauma, or inflammation

•• SBO develops in most cases due to the SBO develops in most cases due to the absence of a limiting hernia sacabsence of a limiting hernia sac

•• Cannot differentiate closed loop SBO Cannot differentiate closed loop SBO caused by transmesenteric hernia vs caused by transmesenteric hernia vs prolapse of intestine under adhesive bandsprolapse of intestine under adhesive bands

FORAMEN OF WINSLOW FORAMEN OF WINSLOW HERNIAHERNIA

•• 8% of all internal hernias8% of all internal hernias•• SB most frequently involved (60%SB most frequently involved (60%--70%)70%)•• TI, cecum, ascending colon (25TI, cecum, ascending colon (25--30%)30%)•• GB, transverse colon, and omental hernias are rareGB, transverse colon, and omental hernias are rare•• Risk factors: enlarged foramen, excessively mobile Risk factors: enlarged foramen, excessively mobile

gut due to a long mesentery, persistence of the gut due to a long mesentery, persistence of the ascending mesocolon, ascending mesocolon that ascending mesocolon, ascending mesocolon that is not fused to the parietal peritoneumis not fused to the parietal peritoneum

FORAMEN OF WINSLOW FORAMEN OF WINSLOW HERNIA: CT FINDINGSHERNIA: CT FINDINGS

•• Mesentery interposed between IVC and Mesentery interposed between IVC and main portal veinmain portal vein

•• AirAir--filled collection in the less sac with beak filled collection in the less sac with beak directed towards the epiploic foramendirected towards the epiploic foramen

•• Absence of the ascending colon in the right Absence of the ascending colon in the right paracolic gutterparacolic gutter

•• ≥≥ 2 bowel loops in the high subhepatic 2 bowel loops in the high subhepatic spacesspaces

SUPRAVESICAL HERNIASUPRAVESICAL HERNIA

•• Supravesical fossa is located between the Supravesical fossa is located between the remnants of the medial and leftremnants of the medial and left--right right umbilical ligamentsumbilical ligaments

•• Sac may remain above the pelvis forming Sac may remain above the pelvis forming an external supravesical hernia or pass an external supravesical hernia or pass caudally and form an internal supravesical caudally and form an internal supravesical herniahernia

BROAD LIGAMENT HERNIABROAD LIGAMENT HERNIA

•• 4% 4% -- 5% of all internal hernias5% of all internal hernias•• SB is the herniated gut in > 90%SB is the herniated gut in > 90%•• > 85% in parous women> 85% in parous women•• Congenital and aquiredCongenital and aquired•• Acquired defects due to surgical trauma, Acquired defects due to surgical trauma,

pregnancy and birth trauma, perforations pregnancy and birth trauma, perforations following vaginal manipulation, PIDfollowing vaginal manipulation, PID

BROAD LIGAMENT HERNIABROAD LIGAMENT HERNIACLASSIFICATIONCLASSIFICATION

•• Type 1= defect caudal to round ligamentType 1= defect caudal to round ligament•• Type 2 = defect above round ligamentType 2 = defect above round ligament•• Type 3= defect between the round and Type 3= defect between the round and

broad ligament through the broad ligament through the mesoligamentum teresmesoligamentum teres

BROAD LIGAMENT HERNIABROAD LIGAMENT HERNIACT FINDINGSCT FINDINGS

•• Cluster of dilated SB with ACluster of dilated SB with A--F levels in the F levels in the pelvic cavitypelvic cavity

•• Distended bowel loops compress the Distended bowel loops compress the rectosigmoid dorsolaterally and the uterus rectosigmoid dorsolaterally and the uterus ventrallyventrally

TRANSMESENTERIC OR TRANSMESENTERIC OR RETROANASTOMOTIC INTERNAL HERNIAS RETROANASTOMOTIC INTERNAL HERNIAS

FOLLOWING LIVER TRANSLANTATIONFOLLOWING LIVER TRANSLANTATION

•• SBOSBO 100%100%•• Medial duodenojejunal junctionMedial duodenojejunal junction 100%100%•• Central displacement of colonCentral displacement of colon 100%100%•• Engorged mesenteric vesselsEngorged mesenteric vessels 100%100%•• Crowding mesenteric vesselsCrowding mesenteric vessels 100%100%•• Cluster of SB loopsCluster of SB loops 88%88%

Blacher Radiology 218:384Blacher Radiology 218:384--388, 2001388, 2001

TRANSMESENTERIC OR TRANSMESENTERIC OR RETROANASTOMOTIC INTERNAL HERNIAS RETROANASTOMOTIC INTERNAL HERNIAS

FOLLOWING LIVER TRANSLANTATIONFOLLOWING LIVER TRANSLANTATION

•• Central displacement of colonCentral displacement of colon 88%88%•• Lack of overlying omental fatLack of overlying omental fat 88%88%•• Depressed duodenojejunumDepressed duodenojejunum 75%75%•• AscitesAscites 50%50%•• Whirl signWhirl sign 50%50%•• Mural SB thickeningMural SB thickening 50%50%•• Saclike massSaclike mass 25%25%

Blacher Radiology 218:384Blacher Radiology 218:384--388, 2001388, 2001

INTERNAL HERNIAS INTERNAL HERNIAS ASSOCIATED WITH RYGBASSOCIATED WITH RYGB

•• TransmesocolicTransmesocolic•• Small bowel mesenterySmall bowel mesentery•• Petersen typePetersen type

INTERNAL HERNIAS ASSOCIATED WITH INTERNAL HERNIAS ASSOCIATED WITH GASTRIC BYPASS: CT FINDINGSGASTRIC BYPASS: CT FINDINGS

•• Swirled mesenterySwirled mesentery•• MushroomMushroom•• Hurricane eyeHurricane eye•• SBOSBO•• Clustered loopsClustered loops•• SB behind SMASB behind SMA•• R sided anastomosisR sided anastomosis

Lockhart AJR 188: 745Lockhart AJR 188: 745--750, 2007750, 2007

THINK INTERNAL HERNIATHINK INTERNAL HERNIA

•• GASTRIC BYPASS PATIENTGASTRIC BYPASS PATIENT

•• OBSTRUCTION WITH NO EXTERNAL OBSTRUCTION WITH NO EXTERNAL HERNIA OR HISTORY OF SURGERYHERNIA OR HISTORY OF SURGERY

•• CLOSED LOOP OR STRANGULATIONCLOSED LOOP OR STRANGULATION

BE VERY SUSPICIOUSBE VERY SUSPICIOUS

•• Gut in abnormal locationGut in abnormal location•• Swirled mesenterySwirled mesentery•• SacSac--like collection of gutlike collection of gut