Splenic Conditions Flashcards
What are the functions of the spleen?
The spleen is primarily a filter, which removes old and damaged red blood cells and platelets.
It also contains immunological cells, including T- and B-cells and reticuloendothelial cells, which remove opsonized bacteria and other particles from the blood.
What is the surgical anatomy of the spleen?
The spleen is roughly divided into three sections: the upper pole, the body and the lower pole.
The arterial supply and venous drainage of the upper pole is from the short gastric vessels, the body is supplied by the main hilar vessels, and the lower pole is supplied by gastroepiploic and omental vessels.
The main splenic artery is a branch of the celiac artery, and the main splenic vein joins the superior mesenteric vein to form the portal vein which then drains into the liver.
The spleen is fixed to the diaphragm and to the lateral abdominal wall by peritoneal attachments which prevent torsion or volvulus of the spleen.
What are the steps of a splenectomy?
The steps of a splenectomy are
- Division of the attachments to the diaphragm and retroperitoneum,
- Division of the lower pole vessels,
- Division of the hilar vessels,
- Division of the short gastric vessels,
- Removal of the spleen, and
- Identification and excision of accessory spleens.
In most cases, the operation can be done laparoscopically, in which case division of the lateral attachments are often done at the end of the procedure after division of the vessels, and the spleen is placed into a bag inside the abdomen so the neck of the bag can be brought out through a port site and the spleen can be morcellated within the bag and removed in pieces.
What is the technique of partial splenectomy?
The goal of a partial splenectomy is to leave a sufficient amount of spleen behind to retain splenic function (although it is not known exactly how much residual spleen is necessary for that purpose).
For spherocytosis, the preferred approach is to divide the lower pole vessels and the main hilar vessels, leaving the upper pole based on the short gastric vessels and stabilized with the phrenosplenic connec- tions.
For a splenic cyst or mass, the surgeon must assess the blood supply to the affected segment and make a decision which part of the spleen to leave behind with an intact blood supply.
Because the spleen is very hard in patients with spherocytosis, the spleen must be divided with a sealing device; in patients with a splenic cyst or mass the residual normal spleen can usually be divided with a stapler.
What is the best management for splenic trauma? [1]
Most children with splenic injury can be managed non-operatively with activity restriction and fluid resuscitation.
The indications for transfusion include unstable vital signs after receiving 20 cc/kg of isotonic fluid, a hemoglobin level of less than 7.0 gm/dl, or signs of active bleeding.
The indication for emergency splenectomy is persistent hemodynamic instability despite blood transfusion.
If laparotomy is necessary, the surgeon should attempt to salvage some or all of the spleen if possible.
For those managed non-operatively, discharge can be done when the child is stable and eating, and activity limitation should be maintained for injury grade + two weeks.
What are the indications for splenectomy in children with immune throm- bocytopenia purpura (ITP)?
ITP is an immunological condition in which the child makes antibodies to his own platelets, which are then destroyed by the spleen.
Most children have the acute form that resolves on its own.
Many children with the chronic form can be successfully treated medically with steroids or intravenous immunoglobulin (IVIG).
Splenectomy is recommended for those who have persistent recurring thrombocytopenia despite medical therapy, or for those who have complications from the medical therapy itself.
What are the perioperative considerations when doing a splenectomy for a child with ITP?
Ideally, the platelet count should be at least 50,000 at the time of splenectomy.
This can usually be accomplished by treating with IVIG within a week of the planned surgery.
For those who cannot achieve an adequate platelet count, platelets should be infused just prior to surgery and continued until after the arterial supply to the spleen has been taken.
Key technical points during the surgery include ensuring that the spleen is completely excised without spilling any splenic tissue, and ensuring that any accessory spleens are identified and excised.
What should be done with a child who has persistent or recurrent thrombocytopenia after a splenectomy for ITP?
The two main reasons for thrombocytopenia after a splenectomy are retained accessory splenic tissue, or breakdown of platelets by reticuloendothelial cells in the liver or bone marrow.
A nuclear spleen scan should be done to identify any residual splenic tissue, and if found this tissue should be removed at a second operation.
What are the indications for splenectomy in children with sickle cell disease (SCD)?
Most children with SCD undergo auto-amputation of the spleen by the age of 10 or so and are therefore not candidates for splenectomy.
However, a small minority will develop a sequestration crisis before that time, which can result in extremely low hemoglobin levels and can be fatal.
Therefore, any child with SCD who has had even one sequestration crisis should have a splenectomy.
What are the perioperative considerations when doing a splenectomy for a child with sickle cell disease? [2]
Children with SCD are susceptible to acute chest syndrome after a general anesthetic and surgical procedure, which can be severe and even fatal.
There is general agreement that these children should be well-hydrated and should have an adequate hemoglobin level prior to surgery, but there is continuing controversy about what that level should be, and whether routine preoperative transfusion is beneficial.
Postoperatively it is important to maintain hydration and hemoglobin level, and to adequately prevent postoperative pain.
What are the indications for splenectomy in children with spherocytosis?
Children with moderate or severe forms of spherocytosis may be considered for splenectomy because of ongoing transfusion requirements, lethargy, jaundice, or discomfort from a massively enlarged spleen.
What are the advantages and disadvantages of partial splenectomy for
children with spherocytosis? [3]
Partial splenectomy, removing approximately 80% of the spleen, has been shown to be very effective in treating the anemia, jaundice and symptoms in children with spherocytosis, while theoretically decreasing the long-term risks of post-splenectomy sepsis and thrombosis.
The operation can be done laparoscopically, but is associated with a higher perioperative transfusion requirement, more pain, and a longer hospital stay than laparoscopic total splenectomy.
There is also a 10–15% risk of regrowth of the splenic remnant with recurrent symptoms and need for a completion splenectomy in the future.
What are the perioperative considerations when doing a splenectomy for a child with spherocytosis?
Most children with spherocytosis are otherwise healthy and can tolerate splenectomy well.
Almost half of patients with spherocytosis will develop gallstones; if they are symptomatic the gallbladder should be removed at the time of splenectomy.
There is controversy about whether asymptomatic gallstones should be removed at the time of splenectomy.
How should splenic cysts be managed?
Splenic cysts are usually congenital and have an epithelial lining.
These must be differentiated from echinococcal cysts, which should be removed, and liquification of a post-traumatic splenic hematoma, which will usually resolve over time.
Symptomatic epithelial cysts should be removed by partial splenectomy if possible, or total splenectomy if partial splenectomy is not technically feasible.
Asymptomatic epithelial cysts can be managed expectantly with serial imaging, but should be removed if they become symptomatic, or if they enlarge beyond 5 cm in diameter.
Techniques such as unroofing or marsupialization, although less invasive, are associated with a very high incidence of recurrence.
How should solid splenic masses be managed?
Solid splenic masses are rare, and usually represent benign lesions such as hemangioma or hamartoma.
These can be managed expectantly if they are asymptomatic, but excision with partial or total splenectomy should be considered if they become symptomatic or enlarge under observation.
Are there any other indications for splenectomy?
Occasionally splenectomy will be indicated for hypersplenism due to portal hypertension, splenic vein thrombosis, HIV infection, glycogen storage disease, or idiopathic splenomegaly.
In some cases of lymphoproliferative disease the diagnosis of lymphoma or leukemia will be suspected, and the spleen will be removed for a tissue diagnosis.
Splenic abscess can usually be managed with antibiotics, but occasionally will require splenectomy.
What is post-splenectomy sepsis and how can it be prevented? [4]
The spleen is involved in preventing infection with encapsulated organisms like Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis. Splenectomy increases the risk of overwhelming post-splenectomy infection (OPSI), which is fatal in more than 50% of cases.
Because of this, all patients undergoing splenectomy should be immunized prior to the operation against all three organisms, and should take prophylactic antibiotics after splenectomy.
Patients who have a splenectomy for trauma should be immunized after they have recovered from their injuries.
What are the risks of thrombosis after splenectomy?
Early after total splenectomy the platelet count in most patients becomes markedly elevated, although this improves over time.
There may be a role for anti-platelet therapy if it exceeds 1,000,000.
There is also a recognized risk of portal vein thrombosis early after splenectomy, a risk which appears to be higher in adults than in children.
Recent long-term follow-up studies have also suggested that there may be an increased risk of thrombotic complications, including thromboembolic pulmonary hypertension, in adults who have had a previous splenectomy.
Regarding splenectomy, all of the following are false except:
A. Electrocoagulation should not be used to achieve haemostasis.
B. Subcostal incision is preferred over midline incision for splenectomy after trauma.
C. Squeeze spleen gently to return as much blood as possible before clamping vessels.
D. Splenic vein should be clamped before artery.
E. Posterior peritoneum and fascia is closed by non-absorbable suture.
C
Squeeze spleen gently to return as much blood as possible before clamping vessels.
Hemostasis during splenectomy after trauma is achieved using electrocoagulation, argon beam coagulation, plagete in suture and absorbable mash.
Midline incision is preferred in splenectomy after trauma, while subcostal incision is good for elective splenectomy.
It is preferable to clamp splenic artery first.
Absorbable suture is used for closure of posterior peritoneum and fascia.
Syed/MCQ
For overwhelming post-splenectomy infection, which of the following is false?
A. Mortality rate is 25 percent.
B. It is caused by pneumococcus (most common), Haemophilus influenzae, and meningococcus.
C. Risk is high in children less than 5 years of age.
D. It is more common in first two years after splenectomy.
E. It is more common in children undergoes elective splenectomy for haematological disease.
A
The incidence of infection after splenectomy in children under 16 years old is 4.4 percent, with a mortality rate of 2.2 percent.
Syed/MCQ
Of the spleen’s many peritoneal attachments, the only vascularised ligaments are:
A the lienorenal ligament containing the splenic vessels and the lienophrenic ligament containing the short gastric vessels
B the lienocolic ligament containing the splenic vessels and the lieno-renal ligament containing the short gastric vessels
C the lienogastric ligament containing the splenic vessels and the lienorenal ligament containing the short gastric vessels
D the lienorenal ligament containing the splenic vessels and the lienogastric ligament containing the short gastric vessels
E the lienogastric ligament containing the splenic and short gastric vessels.
D
The spleen has up to six peritoneal attachments including the lienorenal ligament, which courses along the anterior surface of the left kidney and contains the splenic artery and the splenic vein, and the lienogastric ligament, which envelops the short gastric vessels.
The avascular attachments of the spleen include the lienocolic, lienophrenic, lienopancreatic ligaments and the sometimes-present presplenic fold.
SPSE 1
Which of the following is not true regarding the development and basic physiology of the spleen?
A The splenic primordium originates in the dorsal mesogastrium at around 5 weeks’ gestation.
B The spleen is the primary organ of haematopoiesis until approximately 1 year of age.
C The spleen consists of red pulp and white pulp. The red pulp is primarily responsible for haemofiltration and removal of damaged/ senescent red blood cells and opsonised bacterial particles, while the white pulp contains lymphoid follicles and is a site of antigen presentation and initiation of the humoral immune response.
D The ‘closed’ circulatory theory describes a small portion of splenic blood flow that progresses directly from the arterial to the venous circulation through the splenic capillary bed.
E The ‘open’ circulatory theory describes the majority of the splenic blood that flows from the splenic arterioles into a sinusoidal network lined by the reticuloendothelial cells prior to entering the venous circulation.
B
The spleen is the primary organ of haematopoiesis until approximately 5 months’ gestation, at which point the bone marrow assumes the production of both red and white blood cells.
With gastric rotation, the dorsal mesogastrium folds to situate the spleen in the left upper quadrant anterior to the left kidney.
The dorsal aspect of the dorsal mesogastrium forms the lienorenal ligament while the more ventral portion forms the lienogastric ligament and extends caudad to form the greater omentum.
The two major functions of the spleen are haematological (‘pitting’ and ‘culling’ of red blood cells) and immunologic (production of opsonins and complement, filtration of antigens, antibody production, and stimulation of the lymphoid proliferation).
These functions primarily take place in the red and white pulp, respectively.
A small percentage of the splenic blood flow bypasses the reticuloendothelial system through the ‘closed’ circulation while the majority flows through the reticuloendothelial meshwork and venous sinusoids of the ‘open’ circulation.
SPSE 1
During a routine prenatal ultrasound the diagnosis of transposition of the great vessels is made. The ultrasonographer has difficulty visualising the spleen. All of the following are associated with congenital asplenia except:
A right-sided stomach B biliary atresia C isomerism of the right atrial appendage D Howell–Jolly bodies on postnatal peripheral blood smear e increased rate of postnatal infection with encapsulated bacteria. During a routine prenatal ultrasound the diagnosis of transposition of the great vessels is made. The ultrasonographer has difficulty visualising the spleen. All of the following are associated with congenital asplenia except:
A right-sided stomach
B biliary atresia
C isomerism of the right atrial appendage
D Howell–Jolly bodies on postnatal peripheral blood smear
E increased rate of postnatal infection with encapsulated bacteria.
B
The condition described is congenital asplenism, which is frequently associated with severe cyanotic heart disease, isomerism of the right atrial appendage, a right-sided stomach, central displacement of the liver and peripheral blood smear findings consistent with splenic insufficiency.
Ivemark’s syndrome or asplenia syndrome is the presence of visceral heterotaxy with bilateral rightsidedness. This syndrome is also associated with malrotation and increased frequency of midgut volvulus.
Congenital polysplenism is associated with biliary atresia, situs inversus, absent inferior vena cava, preduodenal portal vein and aberrant hepatic artery.
SPSE 1
A 14-year-old female is struck by a car while riding her bicycle and sustains a grade 4 splenic laceration requiring an emergency splenectomy. Fifteen years later the patient presents again with an adhesive smallbowel obstruction requiring repeat laparotomy. The lysis of adhesions is carried out without difficulty; however, at the time of the operation she is found to have multiple 5 mm to 4 cm purple, fleshy nodules implanted on the surface of the liver, stomach and omentum. Which of the following statements is true about this patient’s condition?
A The most common location for this tissue to be found is within the splenic hilum.
B The tissue is a congenital anomaly that occurs in 20%–30% of the general population.
C The nodules likely represent a malignant process and should be completely resected.
D This process occurs secondary to seeding of the peritoneum with splenic particles following splenic rupture and frequently provides adequate immunologic function to obviate the need for postsplenectomy vaccination.
E This tissue is likely to look similar to normal splenic tissue, histologically, with the exception of having a fibrotic capsule, multiple small vascular tributaries, and an incomplete or disorganised trabecular network.
E
The condition described in this question is splenosis. It results from seeding of the peritoneum following splenic trauma and is most frequently found on the surface of the liver, stomach and omentum.
It is a completely benign process and does not need to be resected unless it is causing a problem secondary to a mass effect.
Histologically, the splenosis nodules appear similar to native spleen; however, they lack the dominant trabecular arterial inflow and structured splenic capsule.
Splenosis often performs pitting and culling (i.e. removes deformed or senescent red blood cells), but for incompletely understood reasons, it does not provide the immunologic function of the native spleen.
As a result, such individuals should be treated as asplenic. options A and B refer to accessory spleens.
SPSE 1
