The treatment of splenic diseases has changed over the past decade, particularly for trauma, from prompt splenectomy in most cases to splenic salvage whenever possible. The most important factors influencing this change are the recognition that the majority of splenic traumas (grades I–IV) can be managed nonoperatively and the risk of infection after splenectomy.
The spleen is the most important peripheral immune organ and contains more lymphatic tissue than all the lymph nodes in the human body taken together. The spleen is connected to the circulatory system and plays a central role in the immune system.
If the spleen is to continue to fulfil its immunological functions, about 25
% of the original weight of a normal-sized organ should be available for preservation, along with adequate arterial blood supply.
Laparoscopic splenectomy is mainly indicated for haematological disorders and only rarely for trauma.
A partial resection of the spleen may be necessary with benign lesions (cysts, hamartoma, etc.) limited to one pole or half of the organ or for diagnostic purposes if other diagnostic measures have not secured a diagnosis.
Anatomical and technical considerations are important safety prerequisites in splenic surgery. The spleen can be considered to have two separate blood supplies:
(a) The main blood supply from the splenic artery and vein and their branches
(b) Supplemental blood circulation through the vessels in the ligaments
The three major aims during splenic surgery are:
(a) Definitive anatomical dissection of the vessels, avoiding pancreatic injury
(b) Avoiding and controlling active haemorrhage
(c) Partial resection that preserves as much of the spleen as possible
The three major complications during or after splenic surgery are:
(a) Bleeding
(b) Pancreatitis and pancreatic fistula
(c) Infections
Patients who have undergone splenectomy should be informed of their immune deficit and vaccinated against pneumococci.
5.1 Problem
The most important problem during spleen surgery is bleeding, from the hilar vessels or the splenic parenchyma itself; it can occur at any stage of the operation and may be difficult to stop. Peri- and postoperative bleeds occur in up to 10 % of cases and depend on concomitant diseases and risk factors. Patients with haematological diseases and/or anticoagulant therapy are at greater risk; portal hypertension is a further risk factor.
Injuries to neighbouring organs, such as the flexure of the left colon and
especially the tail of the pancreas, are far less common but pose serious complications. Postoperative pancreatitis can follow an injury, but blood supply to the tail of the pancreas may be compromised by proximal ligature of the splenic vessels, causing necrosis and possible formation of persisting fistulas.
Key elements for complication-free splenic surgery are knowledge of the surgical anatomy and laparoscopic expertise, as well as adherence to preventive measures and to the step-by-step dissection techniques.
5.2 Surgical Anatomy of the Spleen
For its size, the spleen is very well perfused. It is a soft lymphatic organ and contains about 1/4 of the body’s total lymphoid tissue, but unlike the lymph nodes, it is integrated into the blood rather than lymphatic circulatory system. The hilum of the spleen is located roughly in the middle of the visceral surface, where the branches of the splenic artery enter and the tributaries of the splenic vein leave. This is the only place where it is not covered by the peritoneum. The spleen is suspended in the left upper quadrant by the splenophrenic, gastrosplenic and splenocolic ligaments; its physiological position and its shape can vary according to the position and distension of the neighbouring organs and the position of the body.
Generally the splenic artery has one branch each to the upper and lower poles and itself enters the spleen in the middle of the hilum so that the spleen can be divided into three segments: upper, middle and lower. These segments are quite autonomous in their arterial and venous circulation. The segments are superposed perpendicularly along the long axis of the spleen and are separated by poorly vascularised planes. The splenic branches are considered to be nonanastomosing terminal arteries, except for some intrahilar shunts; there are also a few intersegmental vessels that allow subtotal permeation of the segments with an increase in pressure. Intersegmental connections allow ligature of the main vessel or a catheter embolisation, which is usually be tolerated without total necrosis. Thanks to these poorly vascularised intersegmental zones, the spleen can be partially resected with minimal blood loss.
Based on the distribution of blood vessels within the splenic parenchyma, we distinguish between a central zone near the hilum, a peripheral zone distant from the hilum and an intermediate zone between the two. Understanding these zones of vascularisation is important for classifying the severity of splenic injuries, particularly intraoperative injuries. An intraoperative injury that involves only peripheral (subcapsular) parenchyma opens the peripheral arterioles and venous sinuses. The trabecular vessels are affected in the intermediate area.
Parenchymal injuries of the medial surface penetrating into the central zone often damage the segmental vessels. Surgical measures are determined by the nature and degree of vascular injuries.
5.3 Diagnosis of the Complications
5.3.1 Bleeding
Intraoperative bleeding is not difficult to diagnose, but small vascular injuries may not be recognised intraoperatively and only become apparent postoperatively. They can be best diagnosed on the basis of laboratory work (CBC), cardiocirculatory parameters (clinically) and ultrasound. Drains are only reliable when there is considerable haemorrhagic output, but a drain with no output is by no means a guarantee that there is no bleeding. A diagnostic CT scan for postoperative bleeding is needed only rarely, if at all, in complex cases.
5.3.2 Injury to the Tail of Pancreas
Intraoperative injuries to the tail of the pancreas are infrequent but can be serious, particularly if not recognised intraoperatively. They occur in patients with difficult anatomy and when there is a poor view, in obese patients and in those with splenomegaly, enlarged hilar lymph nodes and kyphosis. These injuries occur most often in the course of a total splenectomy; with partial splenectomy, there is little likelihood of a pancreas injury due to the anatomical distance. Commonly, injuries to the pancreas become clinically apparent during the postoperative course, with symptoms resembling pancreatitis. If a drain is in place, amylase and lipase can be detected in the drain fluid, but it is clinically important only when the levels exceed the serum value by a factor of three. Besides the clinical course, CT is the most useful diagnostic method and will guide the management when there is a fluid collection that requires drainage. Small injuries to the tail of pancreas usually do not cause complications and heal spontaneously, though they can also lead to clinically relevant fistulas.
The clinical effects of a postoperative pancreatic fistula are graded from A to
5.3.2.1 Grade A
The patient is clinically unremarkable, without persistent fistula or abdominal fluid collection. Diagnosis is made with CT. There is no therapeutic consequence and, in general, the hospital stay is not prolonged.
5.3.2.2 Grade B
These patients are symptomatic but stable, requiring diagnostic evaluation and therapeutic intervention. The patient may complain of abdominal pain, fever, nausea, intolerance of oral intake and bowel-related symptoms.
The fluid collection measures at least 3 × 3 cm by CT or ultrasound (US). Therapeutic interventions are antibiotics and enteral nutrition past the ligament of Treitz or parenteral nutrition. The drain should remain in place until the fistula has healed. Invasive intervention (CT-guided drainage) may be necessary and the hospital stay is usually prolonged.
5.3.2.3 Grade C
Clinically unstable patient (sepsis) requiring intensive care. Therapeutic interventions are percutaneous drainage or re-laparotomy if the drain has become dislocated or is not optimally positioned; haemorrhage is common and high mortality is expected.
Postoperative pancreatic fistula (PPF) after splenectomy is a rare but dreaded and sometimes fatal postoperative surgical complication. The PPF after splenectomy can have serious consequences for the patient (readmission, reoperation, radiologically guided percutaneous drainage, prolonged parenteral antibiotics, numerous follow-up visits) and the related public health costs. Inflammation and sepsis, often associated with such fistulas, are responsible for metabolic disturbances that can culminate in multiorgan failure. Complications and their sequelae can only be prevented with perfect planning and excellent execution of the operation, whereby the importance of careful dissection cannot be overemphasised.
5.3.3 Positioning of the Patient During Laparoscopic Splenectomy
For laparoscopic splenectomy, the position of the patient is at least as important as the choice of trocar sites. The patient is positioned in a right semilateral position with the left arm fixed over the head. This permits a better approach to the spleen via the left thoracic aperture. In this position, the spleen hangs from its dorsolateral ligaments and the other organs shift caudally to expose the splenic hilum.
5.3.3.1 Trocar Placement
Three to four trocars are appropriate in most cases. The trocar placement should be chosen carefully on the basis of the size of the spleen. The first trocar is inserted in the umbilical region using an open technique and serves as the camera port. A 12-mm trocar is inserted next on the left medioclavicular line, either cranially or caudally from the level of the umbilicus, depending on the size of the spleen. It serves as the working trocar through which the endostapler is introduced to ligate the splenic vessels. The third is a 5-mm trocar, placed in the epigastric region; it is the second working trocar and is used exclusively to introduce a grasper or a suction device. These three trocars generally suffice. In exceptional cases, a fourth 5-mm trocar can be inserted for a retractor.
5.3.4 Operative Procedure
5.3.4.1 First Step: Mobilisation
Dissection is usually performed from the caudal to cranial direction with gentle dissection of the omentum from the lower pole and visceral aspect and/or splenic hilum. It is important to dissect close to the spleen but without tearing the capsule. In this phase, the short gastric vessels are also severed. The spleen is dissected and mobilised with ultrasonic scissors or a LigaSure® instrument exclusively, avoiding the use of clips and reducing changes of instruments to allow faster and safer dissection.
When the omental attachments on the medial surface and the short gastric and lower pole vessels have been severed, dorsolateral mobilisation can start with severing of the peritoneal fold. Dorsolateral mobilisation should only be done when all the connections on the visceral side have been severed as the dorsolateral fixation holds the spleen in its natural position and prevents it from falling into the medial surgical field. During this phase, great attention should be paid to the tail of the pancreas, which should be treated with utmost care and not injured. Blood supply to the tail of the pancreas by the last branches of the splenic and gastroepiploic vessels should by all means be preserved.
5.3.4.2 Second Step: Dissection of the Hilar Vessels
The hilar vessels should be dissected cleanly and are best transected with an endostapler. With this instrument, even large arteries and congested vessels can be ligated safely. Depending on the size of the hilum, a 45–60-mm vascular cartridge is usually suitable and assures safe closure of the splenic vessels.
5.3.4.3 Third Step: Prevention of Bleeding
The use of haemostatic substances such as collagen fleece and/or fibrin glue has proved to be valuable when there is a pronounced bleeding tendency, as, for example with hepatic cirrhosis, coagulopathies and thrombocytopenia. A suitable laparoscopic device is used routinely to spray the entire splenic fossa with fibrin sealant (TisseelR, Baxter) and tamponade the stumps of the blood vessels and the edge of the pancreatic tail with collagen fleece (TissuFleeceR or HemopatchR, Baxter). Only in exceptional cases is it necessary to drain the splenic fossa; when it is, the drain is removed on the second postoperative day at the latest.
5.4 Partial Splenectomy
5.4.1 Positioning of the Patient and the Trocar Placement
As for a laparoscopic total splenectomy, for hemisplenectomy the patient is placed on the operating table in a right semilateral position. The positions of the trocars other than the umbilical optic trocar differ, with a 5-mm trocar placed in the medioclavicular line; the epigastric trocar has a diameter of 12 mm. For the transsection of the splenic parenchyma, the endostapler is inserted from the medial direction via the 12-mm trocar port on the epigastrium and not caudally as when the splenic vessels are severed for a total splenectomy.
5.4.2 First Step: Mobilisation
For the partial resection, the dissection begins with mobilisation of only that part of the spleen that is to be resected. If the lower half of the spleen is to be removed, the omental attachments including the branches of the gastroepiploic artery are first severed using ultrasonic scissors or the LigaSure® instrument.
If the upper half is to be removed, mobilisation begins with the medial surface at the intended line for parenchymal transsection above the entrance of the main vessels. After the short gastric vessels have been severed, the peritoneal fold is dissected dorsal to the spleen, completing the mobilisation of the half of the spleen that is to be removed.
5.4.3 Second Step: Vascular Dissection
The vessels of the part of the spleen that is to be removed are severed gently and carefully, either by mechanical coagulation or stapler transection. This is the step with the highest risk of intraoperative bleeding and must be completed carefully.
Bleeding from the spleen is usually due to a capsular tear from tension on attachments or small vessels entering the spleen. Immediate pressure and coagulation with LigaSure® or ultrasonic scissors will usually stop the bleeding.
5.4.4 Third Step: Parenchymal Resection
With few exceptions, the parenchyma can be transected with an endostapler using a 60-mm parenchymal cartridge. The parenchyma is first compressed with a long, atraumatic grasper on the planned transection line that the previous vascular dissection has rendered clearly visible. To avoid tearing the capsule and causing bleeding, compression should be applied slowly and stepwise. Only when the parenchyma has been sufficiently compressed is it stapled through the epigastric 12-mm trocar and the resection performed, usually in two or more steps depending on the size of the organ.
5.4.5 Fourth Step: Securing the Resected Edge and Removal of the Specimen
The cut edge of the remaining portion of the spleen is sealed, preferably with a fibrin glue (Tisseel, Baxter) and collagen fleece (TissuFleece) or covered with a Hemopatch® (Baxter) to prevent afterbleeding. Both the fibrin adhesive and the collagen fleece help the spleen adhere to its surroundings quickly and so reduce the likelihood of torsion or buckling, especially in the venous area.
5.5 Haemostasis in Laparoscopic Spleen Surgery
Haemostasis is one of the greatest challenges in laparoscopic surgery. There can be bleeding with both uneventful and eventful laparoscopies. Scars and adhesions can change the anatomy and complicate dissection. The bleeding risk is also higher in patients with abnormal tissue characteristics due to medications such as cortisone, thrombocyte aggregation inhibitors or anticoagulants.
Bleeding resulting from intraoperative developments and difficulties is usually due to inadequate exposure or inability to manipulate the tissue or to equipment failure.
With all these possible causes of bleeding, the most important thing is prevention.
This means that the surgeon must be alert to the fact that there can always be anatomical variations and must ensure that the correct instrument or dissection device is used. It must be borne in mind that all the high-tech devices
nonetheless have their pitfalls and do not always and in every case have the same safety characteristics. Vessels with a diameter of 5 mm or more should be dissected with the LigaSure® or other ultrasonic dissector or with an endostapler.
Even with all preventive measures in place, there can still be bleeding. To manage it, the following materials should be available in the operating room and not have to be fetched from somewhere else. Most important are sutures for laparoscopy, endoloops, collagen fleece and fibrin adhesive. Before the procedure is begun, the team should discuss what is to be done in the case of acute bleeding.
Fast and effective haemostasis is only possible when the source of the bleeding is visible. This means that with spurting blood, the person operating the camera should, without losing the view, quickly retract the trocar a few millimetres to prevent loss of vision. As the very first measure, simple pressure or pinching can temporarily stop the bleeding and let the team calm down. Before final haemostasis can be achieved, the source of the bleeding will usually need to be dissected free for better visibility. To this end, the operating surgeon should best use his/her nondominant hand to keep the bleeding under control and perform the other manipulations with the dominant hand. For venous bleeds, compression with a small sponge introduced into the abdominal cavity through a 10-mm trocar works best. Arteries with a diameter of up to 7 mm can be sealed with a modern coagulation device, an endoloop or a clip, but venous bleeds require suturing. In advanced laparoscopy, the operating surgeon should have perfect mastery of laparoscopic suturing and intracorporal knotting techniques. After a manoeuvre of this sort, the tail of the pancreas and other neighbouring organs should be inspected for accidental injuries. Spurting arterial bleeds require surgical haemostasis by coagulation or suture. Parenchymal bleeds can be stopped very simply and effectively with FloSeal. Oozing from the spleen can be stopped effectively and once and for all with a Hemopatch® or with compression followed by tamponade with collagen fleece using fibrin adhesive. Before a haemostyptic is applied, compression should be applied patiently as long as necessary.
With complicated procedures, it is usually advantageous to use a drain, preferably an active suction drain which, however, should not be located near the source of bleeding.