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General Surgery
Spleen
Built from Skandalakis' Surgical Anatomy: The Embryologic and Anatomic Basis of Modern Surgery
What’s inside
12 sections · 194 slides
Embryogenesis and congenital anomalies
- Hua To (115-205 A.D.) performed possible splenectomies in China The Jewish Talmud described the spleen, techol, as the seat of laughter Maimonides (1135-1204) described blood-purifying properties of the spleen The table opposite sets out the anatomic and surgical history of the organ Read it as the slow separation of splenic myth from splenic physiology Note how recently splenic preservation, rather than removal, became the goal
- Anatomic and Surgical History of the Spleen
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Anatomic and Surgical History of the Spleen (continued)
- Spleen is mesodermal in origin and is the largest lymphatic organ Around the fifth week mesenchymal cells appear between the leaflets of the dorsal mesogastrium Coelomic epithelium of the dorsal mesentery contributes to the early spleen Dorsal mesogastrium supports the embryonic stomach and expands at 5-6 weeks into the greater omentum Mesenchymal cells differentiate into both the capsule and the connective tissue framework
- Spleen stays within the mesenteric expansion but does not follow the omentum downwards It lies between the leaves of the dorsal mesogastrium in fetal and adult life All these events occur on the left side, in the left upper quadrant Origin is neither midline nor bilateral Left surface of the mesogastrium fuses with peritoneum over the left kidney
- Development of the spleen. A. The splenic primordium as it appears on the left side of the dorsal mesogastrium at 6 weeks. B. At 2 months. C. At 4 months. D. Angiogenesis is beginning in the early splenic primordia.
- Development of the spleen. A. The splenic primordium as it appears on the left side of the dorsal mesogastrium at 6 weeks. B. At 2 months. C. At 4 months. D. Angiogenesis is beginning in the early splenic primordia.
- Peritoneal reflections of the spleen develop from the primitive dorsal mesentery. A. Relationships during the primitive embryonic stage. B. Relationships in the adult.
- Development of the splenic ligaments. A. Gastric and splenic rotation. B. Formation of omental bursa and its relation to the spleen. C. Beginning of formation of the greater omentum and its relationship to spleen. D. Formation of two major splenic ligaments.
- True epithelium with a visible basement membrane at 10-20 days Clefts of mesenchymal origin (sinusoids without endothelial lining) at 29-30 days Characteristic shape assumed in the early fetal period; fetal lobulation disappears late prenatally Surface immunoglobulin-bearing B cells and rosette-forming T cells appear around 13 weeks IgM and IgG synthesised in the third trimester; IgA and possibly IgE are not made in fetal life Splenic lobules form around central arteries early in the second trimester
- Asplenia may accompany several other congenital anomalies and is autosomal recessive Splenic hypoplasia is inherited as autosomal dominant Polysplenia may likewise be associated with several other congenital anomalies Polysplenia is distinct from accessory spleen In accessory spleen the normal spleen is present, joined by one or more small separate nodules
- Most compelling evidence points to an error in development of the primary supporting ligaments Ligaments may be too long, too short, too wide, too narrow, abnormally fused, or absent Six ligaments are directly associated: gastrosplenic, splenorenal, splenophrenic, splenocolic, pancreatosplenic, presplenic fold Two are indirectly associated: pancreaticocolic and phrenicocolic Laxity plus abnormally long splenic vessels produces excessive mobility and ptosis Literature blames gastrosplenic, splenorenal and phrenicocolic ligaments most often
- Major and minor splenic ligaments.
- Abnormal fixation allows torsion about an elongated vascular pedicle, causing infarction Presents as an asymptomatic mass, a mass with pain, or an acute abdomen Desai et al. recommend splenopexy as definitive treatment in children, except with infarction Splenectomy if there is no evidence of blood flow to the spleen Rare in children: Abell found only one patient under 10 among 97 cases with torsion Spector and Chappell reported association with gastric volvulus; consider prophylactic gastropexy
- Splenic tissue may fuse with male and female gonads, and with pancreas and liver In males indicated by splenic tissue in the left scrotum Occasionally associated with two rare defects: ectromelia and micrognathia Putschar and Manion: continuous type has a cord of splenic or fibrous tissue to the main spleen Discontinuous type has discrete splenic masses fused to gonadal-mesonephric structures Far less common in women: of 84 reported cases only 6 were female
- Congenital splenic cysts are lined with epithelium; several hundred epithelial cysts reported by 1970 Most reported cases involved children and young adults Panossian et al. reported an epidermoid cyst presenting as generalised peritonitis Accessory spleens are found in one fifth to one third of autopsies Seventy-five per cent of accessory spleens lie at the hilum (splenic porta) Rarely is accessory splenic tissue found in more than two locations
- Habib et al.: accessory spleens occur in 11 to 44 per cent, more with haematological disease May stay silent or cause pathology; abscess is rare but enters the differential of sepsis or PUO CT is the imaging modality of choice and may guide percutaneous drainage Wekerle et al. reported intrahepatic splenic tissue in recurrent idiopathic thrombocytopenic purpura Splenosis is peritoneal splenic tissue from autotransplantation after injury Reported to cause intestinal obstruction from adhesions, pain from torsion, gastric masses mimicking carcinoma
Topography, size and shape
- Lies in the left upper quadrant in a niche formed by the diaphragm posterolaterally Stomach lies anteromedially; left kidney and left adrenal posteromedially Phrenicocolic ligament lies below; chest wall (9th to 11th left ribs) laterally Tail of pancreas is related to the splenic hilum in most cases; not normally palpable Separated from the ribs by the diaphragm and costodiaphragmatic recess; descends 2-5 cm on deep inspiration On roentgenograms typically about 5 cm wide and 14 cm long
- Location of the spleen.
- Recorded extremes of splenic weight are 1 ounce and 20 pounds Spleens of extreme size may be healthy or diseased Size increases with rising blood pressure and after meals Size decreases with exercise and immediately postmortem Splenic lymphoid tissue diminishes after the age of about 10 years Some involution of the whole organ occurs after the age of 60 years
- Michels described three forms: wedge-shaped in 44%, tetrahedral in 42%, triangular in 14% A more useful system recognises two forms Compact type (30%): almost even borders, narrow hilum, few and large arterial branches Distributed type (70%): notched borders, large hilum, small and numerous arterial branches In an enlarged spleen a notched anterior border can be palpated
- Shapes of the spleen.
- Classification of spleen shape based on general arterial distribution.
- Two surfaces for practical purposes: parietal and visceral Convex parietal surface is related to the diaphragm Concave visceral surface relates to stomach, kidney, colon and tail of pancreas On the hilar surface the entering and exiting vessels usually form the letter S Two borders: superior (anterior) and inferior (posterior) Superior border separates gastric from diaphragmatic area; inferior separates renal from diaphragmatic
- Splenic borders.
- Left suprahepatic space: bounded medially by falciform ligament, above by left coronary and triangular ligaments Inferiorly the suprahepatic space opens into the general peritoneal cavity Left infrahepatic space is divided by the hepatogastric ligament, stomach and gastrocolic ligament Anterior division is the perigastric space; posterior division is the lesser sac The healthy spleen is closely related to the lesser sac Lesser sac is almost closed by the splenorenal and gastrosplenic ligaments
Segmental anatomy
- Knowledge of splenic segmentation is imperative for segmental resection Kyber may have been the first to suggest splenic segmentation Skandalakis et al.: there is no consistent segmental arterial anatomy Arterial collaterals prevent a standardised anatomic partial splenectomy based on blood supply Embryological explanation: the organ forms by fusion of vascularised isolated mesenchymal aggregates
- Cast of the spleen with a bifurcated splenic artery. 1, superior segment, 2, inferior segment.
- Gupta et al.: spleens had two lobes (superior and inferior) or three (superior, middle, inferior) Mandarim-Lacerda et al., 66 full-term newborns: two lobar branches in the majority Liu et al., 850 spleens: two lobar arteries in most specimens Remaining specimens in these series had one, three or four lobar arteries The table opposite compares the three studies side by side
- Distribution of "Lobes," "Lobar Branches," and "Lobar Arteries" in Splenic Specimens from Three Studies
- Vasculature of splenic hilum and intraspleen. 1. Common splenic artery; 2. Lobar arteries; 3. Segmental arteries; 4. Submental arteries. Relatively avascular planes between lobes or segments are observed.
- Liu et al. found three to eight segmental arteries in a subgroup of specimens Polar arteries were present in 83% of the spleens Liu examined Redmond et al. found three to seven segments; Voboril reported as many as 10 Vasculature of each segment is largely independent of its neighbours Planes separating segments lie obliquely to the long axis Planes often do not traverse the full thickness from visceral to parietal surface
- Distribution of Polar Arteries in 280 Splenic Specimens
- Arrangement of intrasplenic vasculature manifests transverse pattern of arterial supply to lobes or segments. Spleen is defined as having three to five segments. Anatomically, they are named in sequence of segment 1 to segment 5 from superior pole to inferior pole (S1-S5).
- Diagram illustrating segments and subsegments. 1, polar subsegment; 2, central subsegment; 3, central segment; 4 polar segment.
- Cast of a spleen containing five segments. Blue and yellow, polar; white, green and red, central. Note the avascular planes between the segments.
- Confusion exists between splenic lobe, pole and segment Extrasplenic bifurcation of the splenic artery produces two lobes, superior and inferior Authors propose 'segments' for splenic parts separated by avascular planes Dawson et al.: 71% of spleens had two lobes, 29% three; half were subdivided into two segments Garcia-Porrero and Lemes found intrasplenic arterial anastomoses in about 30.5% of specimens Mandarim-Lacerda: 16.7% of newborn specimens had intersegmental anastomoses
- Cast of a spleen containing anastomoses between the inferior and superior segments.
- Dixon et al.: intrasplenic vessels are lobar and segmented, generally without intersegmental communication They divided the spleen into three-dimensional zones: hilar, intermediate and peripheral Each zone requires a different technique for haemostasis Peripheral zone (arteriolar and venous injury): conservative measures such as microfibrillar collagen Intermediate and hilar zones: ligation, to control trabecular and segmental vessels
- Regions indicated are shaped as a three-dimensional cone described by the length of a radius originating at the point of entrance of the major artery into the spleen. All regions contain penicilli, venules, and sinuses with addition of larger vessels as the hilum is approached.
Peritoneum and ligaments
- Right and left layers of the greater omentum separate to enclose the spleen almost completely The organ is bare only at the hilum The visceral peritoneum provides the serosal covering, or capsule The capsule is as friable as the spleen itself and as easily injured Peritoneal layers enclosing the spleen form its two chief ligaments
- Sagittal view of peritoneum covering the spleen.
- Gastrosplenic and splenorenal ligaments are the two chief ligaments Both are portions of the embryonic dorsal mesentery, or mesogastrium The leaves of the mesogastrium separate to surround the spleen Together these two ligaments form the splenic pedicle Minor ligaments: splenophrenic, splenocolic, pancreaticosplenic, presplenic fold Topographically related: phrenicocolic and pancreaticocolic ligaments
- Peritoneal attachments of the spleen. Inset: Hilum of the spleen, showing the short gastric and gastroepiploic vessels in the gastrosplenic ligament.
- The splenic pedicle. A. Long pedicle with a presplenic fold. B. Short pedicle.
- The portion of dorsal mesentery between stomach and spleen Whitesell: best thought of as a triangle Sides are the upper greater curvature of the stomach and the medial border of the spleen At the apex the superior pole lies close to the stomach and may be fixed to it At the base the inferior pole lies 5 to 7 cm from the stomach Cranial part contains the short gastric arteries; caudal part the left gastroepiploic vessels
- The gastrosplenic ligament connects the stomach and spleen. The two organs may be in contact superiorly, and the ligament is short. Inferiorly, the two organs are 5 to 7 cm apart and the ligament is longer.
- Posterior portion of the primitive dorsal mesogastrium Envelops the splenic vessels and the tail of the pancreas Incising it and mobilising the pancreatic tail reestablishes the primitive condition Its existence is often overlooked: in ten randomly selected operation notes it was never mentioned Outer layer of the gastrosplenic ligament forms the posterior layer of the splenorenal ligament Careless division of the gastrosplenic ligament can therefore injure the short gastric vessels
- The pedicle may be narrow or wide, depending on how much mesogastrium was absorbed into the body wall Effective mobilisation depends not on the ligament but on the length of the splenic vessels after incision A short splenic artery can make it impossible to deliver the spleen out of the abdomen Gently pushing the tail of the pancreas away from the hilum increases splenic mobility Rosen et al.: the splenorenal ligament ranges from 2.5 to 5.5 cm in length
- Splenophrenic ligament: reflection of the mesenteric leaves to posterior body wall and diaphragm It lies at the upper pole, close to the stomach; may be a reflection of the gastrosplenic ligament Usually avascular, but inspect it for bleeding after section If it reaches the hilum it may contain the pancreatic tail and all the splenic vessels Splenocolic ligament: remnant of the extreme left end of the transverse mesocolon Being a secondary attachment it should contain no large vessels, but polar vessels may lie close
- Pancreaticosplenic ligament is present when the pancreatic tail does not touch the spleen It is a cordlike formation, usually thin, and often carries the caudal pancreatic artery Presplenic fold lies anterior to the gastrosplenic ligament, described by Henry Usually free on its lateral border, but may be attached in a large diseased spleen May derive from the anterior limb of the inverted-Y arrangement of some hila Often contains the left gastroepiploic vessels
- Develops at the midgut-hindgut junction after the descending colon becomes retroperitoneal It is the rudimentary left end of the transverse mesocolon; smooth muscle migrates in from mesocolic taeniae Fixes the splenic flexure in place and is deformed by the growing spleen into a pocket Extends between splenic flexure and diaphragm; the spleen rests on it but is not attached to it Acts as a barricade at the left paracolic gutter There is no right phrenicocolic ligament, so 'left phrenicocolic' is a misnomer
- Relation of the pancreaticocolic, phrenicocolic, and splenocolic ligaments to the spleen.
- Several unnamed peritoneal folds exist that anatomic textbooks do not describe clearly The most constant is an avascular fold from the left upper omentum to the lower pole of the spleen Morgenstern named it the criminal fold because careless traction traumatises the spleen Rarely, ligamentous bands connect the summit of the convex surface to the diaphragm Sustentaculum lienis: a horizontal shelf between the phrenosplenic and splenocolic attachments Poulin and Thibault: rarely seen at open surgery but readily seen through the laparoscope
- Highly diagrammatic presentation of the spleno-omental "criminal" fold of Morgenstern from the left upper quadrant (LUQ) of the omentum to the medial part (MP) of the lower splenic segment and lower pole (P).
- Suspensory ligaments of the spleen.
Splenic mobility
- Ligaments determining splenic position
- Schematic drawing of horizontal sections viewed from the head illustrates Taveras' 65 concept of the mobility of organs caused by change in position. A. With the patient in the supine position, the liver and spleen remain in a posterior position. B. With the patient in the left lateral decubitus position, the right kidney and descending duodenum drop forward and the left lobe of the liver extends anteriorly toward the stomach, causing a prominent indentation on the anterior surface of the stomach. C. With the patient in the right lateral decubitus position, the left kidney and spleen and tail of the pancreas extend forward. The descending duodenum drops laterally and posteriorly, effacing the inferior vena cava. The left lobe of the liver does not indent the anterior surface of the stomach as prominently as in the left decubitus position.
- Peritoneal covering of the splenic vessels is continuous with the splenic capsule Pancreatic fluid in acute pancreatitis can violate that covering This can produce an intrasplenic pancreatic pseudocyst with splenic rupture and haemorrhage McMahon et al. reported one such event and collected 19 previously reported cases
Arterial supply
- In most people the splenic artery is a branch of the celiac trunk It arises with the common hepatic and left gastric arteries The commonest form of the celiac trunk is tripodal Michels: the tripodal form occurs in 82% of individuals Van Damme and Bonte report the tripodal form in 86% Atypical origins replace the tripod with a dipodal or tetrapodal pattern
- Usually courses leftward in close relation to the upper border of the pancreas Occasionally runs in front of or completely behind the pancreas Very rarely lies partially or totally within the pancreatic parenchyma Termination at the splenic porta is unpredictable in its number of branches Length varies from 8 to 32 cm and diameter from 0.5 to 1.2 cm Passes retroperitoneally under the posterior wall of the omental bursa, looping above and below the pancreas
- Relation of splenic artery and splenic vein. A. Vein posterior to artery (this is the usual pattern). B. Vein both anterior and posterior to artery. C. Vein anterior to artery (this is the least common configuration).
- Relation of splenic artery and splenic vein. A. Vein posterior to artery (this is the usual pattern). B. Vein both anterior and posterior to artery. C. Vein anterior to artery (this is the least common configuration).
- Relation of splenic artery and splenic vein. A. Vein posterior to artery (this is the usual pattern). B. Vein both anterior and posterior to artery. C. Vein anterior to artery (this is the least common configuration).
- Michels' four-part segmental classification: suprapancreatic, pancreatic, prepancreatic, prehilar Most commonly divides into two major branches, in 80 to 94% of cases Less commonly it divides into three principal branches Garcia-Porrero and Lemes: branches varied from 5 to 20, averaging 11 Michels found terminal branch numbers ranging between 3 and 38 Skandalakis et al., after 29 cadaver dissections, saw no consistent pattern of branching
- Segmental Origin of Splenic Arterial Branches
- Segmental Origin of Splenic Arterial Branches (continued)
- Segmental Origin of Splenic Arterial Branches (continued)
- General scheme of splenic artery branches. Asterisk () indicates present in only 20 percent of cases.
- Skandalakis et al.: in 29 dissections all short gastric arteries arose from proper splenic branches Helm: common origin from the left gastroepiploic artery or from proper splenic branches Michels found an average of two to four, and as many as nine Four to six were found in each specimen of the Skandalakis series, 145 in 29 cadavers They were considered end arteries, not anastomosing at the greater curvature They anastomose with the cardiac branches of the left gastric artery
- Keramidas: the short gastric arteries provide the collateral circulation of the spleen Farag et al.: they sustain only the upper third of a normal spleen after removal of the lower two-thirds Petroianu: in 50 patients with schistosomal portal hypertension, splenogastric arteries numbered 1 to 13 In 32 of those cases the upper pole stayed viable after division of both splenic artery and vein Viability was presumed to arise from gastric-to-splenic parenchymal anastomoses Romero-Torres: true splenic supply is splenic artery plus short gastrics plus left gastroepiploic
- Michels: the left gastroepiploic arises from the splenic trunk 72% of the time It arises from the inferior terminal splenic branch or its branches 22% of the time Skandalakis series: from the distal splenic trunk in 18 and from terminal hilar branches in 10 cadavers Posterior gastric artery supplies the dorsum of the fundus and upper body of the stomach It arises from the main splenic stem before the terminal bi- or trifurcation at the hilum Reported incidence ranges from 4% to 99% across studies from 1729 to 1991
- Reported Incidence of Posterior Gastric Artery
- Reported Incidence of Posterior Gastric Artery (continued)
- Reported Incidence of Posterior Gastric Artery (continued)
- Reported Incidence of Posterior Gastric Artery (continued)
- Dorsal pancreatic artery is Kirk's supreme pancreatic artery; about 1.5 mm across, posterior to the splenic vein Michels considered it the most variable of the celiacomesenteric vessels Lippert and Pabst: arises from splenic artery 40%, celiac trunk 28%, common hepatic 17%, SMA 15% It gives the transverse (inferior) pancreatic artery to the left Its right branch anastomoses with arteries on the ventral surface of the pancreatic head Transverse pancreatic artery may be single, double or absent, and may or may not anastomose with splenic arteries
- Possible sites of origin of the dorsal pancreatic artery (percentages from Lippert and Pabst 82 ). More than half of these arteries arise from the proximal splenic artery or the celiac trunk.
- Possible configurations of the blood supply to the distal pancreas. Type I, blood supply from the splenic artery only. Type II, blood supply from the splenic and transverse pancreatic arteries with anastomosis in the tail of the pancreas. Type III, blood supply from splenic and transverse pancreatic arteries without distal anastomoses. This type is susceptible to infarction from emboli in the transverse artery.
- Highly diagrammatic illustration of two variations of the great pancreatic artery.
- Great pancreatic artery (arteria pancreatica magna of Von Haller) is one of the largest splenic branches It is the chief blood supply of the distal body and tail of the pancreas If singular it usually arises from the midportion of the splenic artery Van Damme and Bonte: one caudal pancreatic artery in 32%, two in 46%, more in 22% Caudal pancreatic arteries arise from the terminal splenic artery, left gastroepiploic or a hilar branch When present at the hilum a caudal pancreatic artery can supply accessory splenic tissue
- Simple portal-azygous "disconnection." A, Ligature of the left gastric vessels. B, Coagulation (or clipping) and cutting of the vasa brevia. C, Continuous locking suture of the anterior and posterior walls of the stomach. (With permission of R. Romero-Torres; modified.)
Venous drainage, lymphatics and innervation
- Originates from several veins leaving the hilum, joining at variable distances from it Polar tributaries are not uncommon Large in calibre but without the tortuosity of the splenic artery Passes through the splenorenal ligament with the artery and pancreatic tail, deep to the pancreas Receives pancreatic tributaries, lying inferior to the splenic artery and indenting the dorsal pancreas Joins the superior mesenteric vein deep to the pancreatic neck to form the portal vein
- Anatomy of the splenic vein.
- Lymphatic vessels arise from the splenic capsule and some larger trabeculae There is no provision of lymphatics for the splenic pulp Rouviere's splenic chain: suprapancreatic nodes, infrapancreatic nodes, afferent and efferent vessels Weiss et al.: pancreatic tumours divide the splenic nodes into hilar and pancreatic tail groups Splenopancreatic glands along the splenic artery form the largest group of splenic nodes These nodes drain the stomach as much as the spleen
- Lymphatic drainage of the spleen.
- Nerve supply arises from the more medial and anterior parts of the celiac plexus Visceral fibres accompany the splenic vessels into the hilum Allen stated that fibres from the right vagus or posterior vagal trunk also reach the spleen This has been questioned by degeneration studies after vagotomy in cats Myelinated, probably sensory fibres occur at about 1:20 to unmyelinated autonomic fibres Sensory fibres terminate in the spinal cord at T6 to T8
- Splenic innervation.
Histology and physiology
- The spleen is 75-85 per cent red pulp and approximately 20 per cent white pulp Some arterioles open directly into sinusoids as a closed circulation Others open into meshwork as part of an open circulation Open circulation processes 80-90 per cent of splenic blood flow In open circulation blood passes through capillaries into the red pulp Red pulp macrophages in intercellular gaps phagocytose damaged red cells and particulate matter
- Splenic blood flow and red cell handling
- Functions of the spleen
- Splenic Functions
- Splenic Functions (continued)
Surgery of the spleen
- Sample Preoperative Checklist
- Sample Preoperative Checklist (continued)
- Total open splenectomy may be performed by an anterior or a posterior approach Anterior: incise the gastrocolic ligament, enter the lesser sac, then ligate the splenic artery Posterior: incise the posterior layer of the splenorenal ligament and mobilise the spleen to the right The posterior approach then ligates the artery while working in the greater peritoneal cavity The aim of both approaches is ligation of the splenic pedicle Choice depends on the indication, the disease and the surgeon's knowledge of splenic anatomy
- The anterior and posterior approaches to total splenectomy.
- Steps of the anterior approach
- Mass ligation follows incision of the posterior part of the splenorenal ligament The ligature includes the presplenic fold and the gastrosplenic ligament It also includes the splenic artery and the incised portion of the splenorenal ligament With a well-developed presplenic fold, six sheets of peritoneum, fat, nodes and pancreas may fuse into one mass The lesser sac and the space between presplenic fold and gastrosplenic ligament may be obliterated
- Diagrammatic section through the splenic pedicle containing presplenic fold, gastrosplenic ligament, and splenorenal ligament. Vessels, fat, lymph nodes, accessory spleens, and the tail of the pancreas are all present.
- Splenectomy by the anterior approach. A, Anterior approach and access to the lesser sac. B, Ligation of the splenic artery and the short gastric arteries and vein. C, Ligation of the splenic vein.
- Splenectomy by the posterior approach.
- The Technical Steps in Performing a Splenectomy
- Requires mature judgement and technical skill: knowing when to preserve and when to excise Decision rests on the age of the patient, the condition of the patient and the condition of the spleen Every attempt should be made to preserve the spleen in children, whose exposure to encapsulated organisms is limited Above about age 30 splenic preservation becomes less necessary and less important In older patients preservation is decided by grade of injury and haemodynamic and metabolic stability
- Complete mobilisation of the spleen is absolutely necessary This means freeing all retroperitoneal, diaphragmatic and colonic attachments All the short gastric vessels should be divided to allow full examination for injury The paediatric splenic capsule is relatively thick because the myoepithelial capsule is retained As the spleen matures the myoepithelial elements thin out The paediatric capsule is more forgiving and holds sutures far better than the adult capsule
- Partial splenectomy is a feasible method of preserving immunologic function after trauma At least one-third and preferably one-half of viable spleen should be preserved Essential steps: adequate incision and temporary splenic artery occlusion Then atraumatic mobilisation and selective ligation of segmental vasculature Then controlled intrasplenic dissection with individual ligation or clipping of intraparenchymal vessels Drains are not recommended unless there is concomitant pancreatic injury
- Poulin and Thibault: know the standard anatomy and variations before attempting the operation Brunt et al.: it should be the procedure of choice for a normal or near-normal sized spleen Waldhausen and Tapper found it safe in children with faster return to normal activity Park et al.: the lateral approach takes longer but gives less blood loss and shorter stay Diaz et al.: hospitalisation 2.3 days versus 8.8 days for open splenectomy Targarona: avoid parenchymal rupture, cell spillage and retained accessory spleens
- Splenectomy is of little or no benefit in sickle-cell anaemia, cold antibody immune haemolytic anaemia and G6PD deficiency Operative morbidity of splenectomy is 15-50 per cent and mortality 6-27 per cent Goal is rapid, safe removal with minimal blood loss and minimal injury to adjacent structures Commonest complications to avoid: atelectasis, subphrenic abscess and postoperative haemorrhage from the splenic bed Al-Salem: splenectomy for massive splenomegaly in children is safe with good perioperative care
- After rupture, evaluate the organ and decide whether it is salvageable Consider partial splenectomy or splenorrhaphy Evaluate topical items, haemostatic agents or a splenic mesh wrap Consider autotransplantation to preserve immunological function Weber et al.: autotransplantation into the greater omentum when in situ preservation is impossible Metwally and Ravo: partial splenectomy survives bacterial challenge better than autotransplantation
- A, Splenic rupture with hematoma. B, Splenorrhaphy with omental fixation. C, Partial splenectomy with omental fixation.
- Splenic mesh wrap. Top left, Passage of injured spleen through hole in center of mesh. Top right, Wrapping spleen in mesh. Bottom, Sewing opposite edges of mesh to each other to create tamponade.
- Autotransplantation.
- Nonoperative management has emerged as the commonest method of splenic conservation Powell et al.: successful in more than 90 per cent of children with blunt splenic trauma It has not been as successful in adults, whose splenic anatomy and injury mechanism differ Krause et al.: stable patients aged 55 and over without major transfusion or other abdominal injury may qualify Velmahos et al.: more than one unit transfused or severe blunt injury predicts eventual surgery Peitzman et al.: 38.5 per cent went straight to laparotomy; 54.8 per cent were managed nonoperatively
- Flow chart for decisions in the management of splenic injuries. Asterisk () indicates transfusions required for abdominal injury. DPL, diagnostic peritoneal lavage; RBC, red blood cell count; CT, computed tomography; US, ultrasonography. (Modified by DV Feliciano from Luna GK, Dellinger EP. Nonoperative observation therapy for splenic injuries: a safe therapeutic option? Am J Surg 1987;153:463; with permission.)
- Midline incision is the incision of choice for most indications Suits trauma, hypersplenism with coagulation problems, staging laparotomy and massive splenomegaly Advantages: safe removal of any size spleen, quick to make, little blood loss It also allows full abdominal exploration and treatment of associated problems Left subcostal incision suits a mass in a normal or twice-normal spleen with no other procedure planned No difference in postoperative complications between midline and subcostal incisions
- Incision for total splenectomy.
- Advice on drains ranges from always to never Drains are used to prevent a left subphrenic collection and abscess Risk of subphrenic infection rises when the gut is opened, in hypersplenism, and with pancreatic injury or malignancy The main problem is ascending infection inoculating the splenic bed A drain may therefore cause rather than prevent a subphrenic abscess Carmichael et al. supported selective splenic bed drainage
- Ellison and Fabri: 4.2 per cent subphrenic abscess in 1,944 splenectomies Across five studies, 6.5 to 48 per cent subphrenic infection with drains versus 0.4 to 12 per cent without Pachter et al., randomised: no subphrenic infection in either 23 undrained or 30 Jackson-Pratt drained patients Ugochukwu and Irving: 282 splenectomies with closed suction drains removed at 3 to 5 days, 0.71 per cent infection Chassin advises drainage for pancreatic injury or incomplete haemostasis Three drain types: Penrose (no suction, two-way route), open sump suction, closed suction (may occlude with clot)
- Splenic artery aneurysms are the commonest visceral artery aneurysms and may be multiple They occur most frequently in the distal splenic artery Multiparous women are a well-recognised risk group, by an uncertain mechanism Portal hypertension is associated with increased risk, probably from increased splenic flow Most are asymptomatic and are found as a calcified lesion in the left upper quadrant Majeski: imaging distinguishes an aneurysm from a calcified tortuous splenic artery
- Some present with left upper quadrant pain; a small percentage proceed to rupture Of those that rupture, 25 per cent show the double-rupture phenomenon Bleeding is first contained in the lesser sac before free rupture into the peritoneal cavity Pregnant women are at particular risk; resect ideally in the midtrimester Aneurysms under 2.5 cm may be observed carefully Estimated prevalence ranges from 0.098 to 10.4 per cent; 0.16 per cent in 28,500 unselected autopsies
- Aneurysms away from the celiac axis, outside the pancreas and away from the hilum: excise with proximal and distal ligation Aneurysms deeply embedded in the pancreas: ligate the feeding vessels and leave the devascularised sac in situ Aneurysms at the splenic hilum require concomitant splenectomy Partial embedding in the distal pancreas may warrant distal pancreatectomy with splenectomy Symptomatic or expanding aneurysms should undergo resection Embolisation is feasible, particularly when surgery is contraindicated
- Type of procedure performed is dictated largely by the site of the aneurysm. Top left, When feasible, the aneurysm should be excised and the splenic artery ligated. Bottom left, If the aneurysmal sac is embedded within the pancreas, then proximal and distal ligation of the artery should be performed. Right. Distal aneurysms may be treated by excision with either the spleen or a concomitant distal pancreatectomy.
- Selected aneurysms may be successfully embolized with Gianturco coils.
- Hilum and pancreatic tail touch in about one third of individuals They lie within 1 cm of each other in about half the population In 50 per cent the closest approach of the pancreas is at the middle of the spleen In 42 per cent the closest approach is near the inferior pole The great pancreatic artery is the major artery limiting mobilisation of pancreas from spleen Whitesell: the tail can be dissected back 3.5 to 5.0 cm; Phelan et al. suggest 2 to 3 cm
- Relations of the tail of the pancreas to the spleen.
Indications for splenectomy
- The four indications for splenectomy
- Trauma is the primary disorder causing splenic haemorrhage; external or internal External trauma is the commonest disorder of the spleen, blunt or penetrating The spleen is injured by blunt trauma more often than any other abdominal organ Blunt injury typically accompanies rib fractures or contusion of the left flank or lower chest Chest radiograph may show elevated diaphragm, rib fractures or pleural effusion Its protected posterior position means high-energy blunt trauma splits or fragments the solid organ
- The Traumatic Indications for Splenectomy in Hemorrhage
- Internal trauma accounts for 10 to 30 per cent of splenic injuries and splenectomies Most often intraoperative injury; infrequently spontaneous rupture of an enlarged spleen Intraoperative splenic injury complicates 2 per cent of abdominal operations Commonest mechanism: traction on the greater omentum avulsing its attachment to the inferior pole Avoid it by ligating and dividing that attachment, or retracting towards the patient's left foot Spontaneous rupture is unlikely in a normal spleen; commonest causes are malaria and infectious mononucleosis
- The Nontraumatic Indications for Splenectomy
- The Nontraumatic Indications for Splenectomy (continued)
- Accelerated removal of one cell line gives anaemia, leukopenia or thrombocytopenia Involvement of all three lines produces pancytopenia Hypersplenism is an exaggeration of the normal splenic physiologic state Characterised by splenic enlargement, fall in one or more blood lines, and compensatory marrow hyperplasia There is increased cell turnover of the affected cell lines The diagnosis is correct only if some improvement follows splenectomy
- Primary hypersplenism is a diagnosis of exclusion, with no apparent aetiology True primary hypersplenism is exceedingly rare and usually found in women Diagnosis is made only after an extensive search for other causes Secondary hypersplenism is found in association with a specific disease process Splenomegaly is enlargement from any cause; hypersplenism is excessive removal causing cytopenia More than 90 per cent of patients with hypersplenism do not have splenomegaly
- Diseases Associated with Secondary Hypersplenism
- Diseases Associated with Secondary Hypersplenism (continued)
- Diseases Associated with Secondary Hypersplenism (continued)
- Four categories cause cytopenia: congenital anaemias, haemolytic anaemias, white cell malignancies, miscellaneous Spherocytosis and elliptocytosis produce round and ovoid red cells respectively Their shape makes passage through the splenic filter difficult Red cells pass through the spleen about 1,000 times per day, giving cords and sinuses many chances to trap them Splenectomy removes the filter and improves red cell survival Schwartz: for hereditary spherocytosis splenectomy is curative; for ITP it is therapeutic
- ITP involves an immune mechanism causing premature platelet destruction and low counts Signs are purpura or ecchymosis and bleeding into gastrointestinal, urinary or genital tract Occurs mostly in women and may follow an upper respiratory infection Initial treatment is with steroids If steroids fail or disease recurs, splenectomy produces a favourable response 85 to 95 per cent of the time Removal of accessory spleens must also be done; ITP is about 20 per cent of haematological splenectomies
- Lymphoma and leukaemia can produce hypersplenism during their chronic course Lymphocytic lymphoma and chronic lymphocytic leukaemia cause splenic infiltration and splenomegaly This gives slow transit of blood elements through the spleen and pancytopenia Chromium-labelled red cell studies confirm splenic sequestration Splenectomy can ameliorate the pancytopenia in these patients Cusack et al.: early splenectomy in CLL with Hb 10 g/dL or platelets 50 x 10^9/L improves survival
- Since 1971 laparotomy has been recommended for more accurate staging of Hodgkin's lymphoma Taylor et al.: of 825 patients staged, 356 (43%) had their clinical stage changed Stage increased in 296 patients (36%) and decreased in 60 (7%) Splenectomy must remain part of staging: the spleen was the only involved tissue in 160 of 321 positive cases With better imaging, reliance on staging laparotomy has diminished Baccarani: laparoscopic staging is oncologically equivalent and functionally superior to open staging
- Ann Arbor Staging System for Hodgkin's Disease
- The tissues to be removed or to undergo biopsy in a staging laparotomy for Hodgkin's disease. Splenectomy, liver biopsy, and lymph node sampling in the specific sites are shown. Bone marrow biopsy can be done if necessary.
- In North America nonparasitic cysts are far commoner than parasitic ones Nonparasitic cysts usually occur between the ages of 10 and 40 years In decreasing frequency: pseudocysts, haemangiomas, epidermoid cysts and dermoid cysts Most splenic cysts are unilocular (80%), so CT is the preferred detection method Splenectomy is usually the treatment of choice except for small nonparasitic cysts Commonest splenic tumours are vascular: haemangioma, haemangioendothelioma, lymphangioma, hamartoma
- Malignant Splenic Lesions
- Malignant Splenic Lesions (continued)
- Malignant Splenic Lesions (continued)
Anatomic complications of splenic surgery
- Summary of Anatomic Complications of Some Splenic Procedures: vascular injury
- Summary of Anatomic Complications of Some Splenic Procedures: vascular injury (continued)
- Summary of Anatomic Complications of Some Splenic Procedures: organ injury
- Summary of Anatomic Complications of Some Splenic Procedures: inadequate procedure
- Summary of Anatomic Complications of Some Splenic Procedures: inadequate procedure (continued)
- Postsplenectomy haemorrhage results from surgical error or from haemolytic disease causing pathological bleeding Martin and Cooper: haemorrhage mentioned in 2.8 per cent of 777 splenectomies by 11 authors Vascularisation of the splenic ligaments increases with portal hypertension Careful division and ligation between clamps is therefore essential Two major sources of bleeding after arterial ligation and splenic removal exist The short gastric veins are a further source
- First source: polar arteries arising proximal to the ligature A superior polar artery may arise from the third segment of the splenic artery Second source: retrograde bleeding from splenic arteries distal to the ligature Short gastric, caudal pancreatic and left gastroepiploic arteries may arise beyond the ligation point Such vessels must be identified and ligated separately Where possible the ligation should be distal to the origin of the left gastroepiploic artery
- Diaphragmatic trauma is recognised; a full-thickness defect is repaired with through-and-through interrupted nonabsorbable sutures Proximity of the pancreatic tail may cause injury to pancreatic ducts, vessels or the tail itself Duct or vessel injury is treated by ligation; severe tail injury requires resection with closed drainage Fourteen pancreatic injuries (2.2 per cent) occurred among 632 splenectomies in four series Gastric injury or ischaemia of the gastric remnant may follow sacrifice of the short gastric arteries Gastrorrhaphy and inversion is the procedure of choice for superficial or full-thickness gastric injury
- Distal transverse colon, splenic flexure and proximal descending colon may be injured The segments related through the splenocolic and phrenicocolic ligaments are most vulnerable The pancreaticocolic ligament is occasionally involved, depending on its width and the spleen's size Gentle handling and ligation of these ligaments avoids colonic injury; repair the wall in two layers A megaspleen may be fixed to the left adrenal, kidney and ureter Bleeding must be controlled; an injured ureter needs anastomosis
The spleen in malignancy and systemic disease
- Metastatic carcinoma of the spleen is rare Routine autopsy series find splenic involvement in 0.3 to 9 per cent of patients with cancer Berge: of 4,404 postmortem cases with spread, only 312 (7.1%) had splenic metastasis Splenic metastasis usually reflects late disseminated disease Berge found microscopic splenic metastasis in 70 per cent of subjects with metastases in six or more organs Marymont and Gross: 30-67 per cent of splenic metastases arise from breast and lung primaries
- Proposed bases of splenic resistance to metastasis
- Hull et al. attributed splenic protection in rats against chemically induced colonic tumours to immunologic surveillance Production of antineoplastic substances by the spleen has been reported Miller and Milton: tumour cells implanted in mice grow more slowly in spleen than in liver Sato et al.: growth of colonic tumours in mice was enhanced after splenectomy Wanebo et al.: 5-year survival after gastrectomy 20.9% with elective splenectomy versus 31% without (P<0.0001) Davis et al.: splenectomy is a probable factor in decreased survival after surgery for regional colorectal cancer
- Liver and spleen are fellow travellers in several well-known diseases Splenomegaly tends to accompany hepatomegaly The spleen is extremely sensitive to elevation of vascular pressure Splenomegaly can follow hepatic portal hypertension because of the vascular relations of the two organs Splenic involvement in Budd-Chiari syndrome is well known Venography, splenoportography and splenorenal shunts have been developed
- Diagrammatic illustration of the selective distal splenorenal shunt.
- Pancreatitis and pancreatic carcinoma are the commonest causes of splenic vessel occlusion Splenic venous thrombosis frequently complicates pancreatic cancer and is easily diagnosed on CT Arterial thrombosis is rarely observed Chronic pancreatitis can cause splenic rupture via peptic digestion and an intrasplenic pseudocyst Haemorrhagic pleural effusion may follow such an event Frey et al.: pseudoaneurysms from pancreatitis are under 5 per cent of splenic artery aneurysms
- Pseudoaneurysms resulting from pancreatitis may cause hemorrhage by rupture either into the pancreatic ductal system or directly into the stomach or duodenum. SA, splenic artery.
- Diagrammatic representation of collateral circulation characteristic of isolated occlusion of the splenic vein.
- HIV infection may result in immune thrombocytopenia The aetiology is not entirely clear but treatment resembles that of classic ITP Response to steroids is unpredictable and short-lived Splenectomy gives immediate resolution of thrombocytopenia in the majority of cases It does not appear to increase the incidence of opportunistic infections Tsoukas et al.: absence of a spleen in asymptomatic HIV may benefit disease progression
- Four indications: hemorrhage, hypersplenism, Hodgkin's staging, hodgepodge Preserve the spleen where possible, above all in children; partial resection beats autotransplantation Anterior approach ligates the artery through the lesser sac; posterior approach mobilises first Artery before vein: the spleen decompresses into the portal system and shrinks Ligate distal to the left gastroepiploic origin and hunt polar vessels before closing If you drain, drain closed and remove it in 3 to 5 days
- References
- References (continued)
- Skandalakis' Surgical Anatomy: The Embryologic and Anatomic Basis of Modern Surgery
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