splenectomy if splenic hilum nodes were grossly normal.130

Other tumors of the left upper quadrant and retroperitoneum may require splenectomy including

large renal cell carcinomas, left adrenal tumors, and retroperitoneal sarcomas that may infiltrate

upwards into the spleen. Often the use of splenectomy performed in these situations is to provide

adequate exposure to cleanly dissect bulky disease that lies posterior to the spleen. Although the

asplenic state does make patients susceptible to infections, the spleen should be viewed as an

expendable organ if necessary to accomplish complete resection of malignancies and there should be no

hesitation to remove the spleen in those settings to achieve the appropriate complete resection.

IATROGENIC SPLENECTOMY

A poorly reported and uncommonly discussed area of spleen surgery would be removal or preservation

of the iatrogenically traumatized spleen during unrelated abdominal operations. Procedures in which

there is mobilization of the left upper quadrant with reflection of the spleen and pancreas medially to

expose retroperitoneal tissue, such as in left adrenalectomy, and left nephrectomy put the spleen at

risk.131 Simple mobilization of the splenic flexure of the colon can lead to bleeding from the inferior

pole of the spleen that may be difficult to control. The ligaments that go directly from the omentum to

the capsule of the spleen may be the most common cause of iatrogenic splenic trauma as it is quite a

common practice to aggressively retract the omentum as needed for exposure. There are direct branches

that are sometimes sizable from the omentum to the splenic capsule, which could result in capsular

disruption and troublesome bleeding. A national database on antireflux procedures of 86,411 patients

reported an incidence of iatrogenic splenectomy of 2.3%, which translates into 1987 iatrogenic

splenectomies for that indication alone.132

Probably the best data for the incidence of iatrogenic splenectomy come from the recently reported

series from Vanderbilt, which listed 73 iatrogenic splenectomies over a 10-year period or an average of

7 per year.26 This comprised 8.1% of all splenectomies performed during that time interval. There are

probably additional numerous times minor or moderate injuries are inadvertently made to the spleen

during unrelated surgeries in which the spleen was not removed but was repaired or salvaged. Just as in

trauma to the spleen, the techniques of splenorrhaphy can be employed to preserve the spleen. A recent

report indicates that the use of a mesh wrap splenorrhaphy even in the setting of bowel surgery does

not lead to an increased incidence of infection.31 For minor capsular disruption, the use of the argon

beam coagulator for surface cautery is a helpful technique.

Several studies have looked at the incidence and effects of inadvertent splenic injury during

colectomy. The Mayo Clinic surveyed 13,897 colectomies and found 59 splenic injuries (0.42%). The

majority of these occurred during mobilization of the splenic flexure.133 The 30-day morbidity rate for

this subgroup of patients was 34% and, most concerning, the mortality rate was 17%. There were no

clear episodes of sepsis. A second large study from the California Cancer Registry of almost 42,000

patients showed that there was a similar rate of inadvertent splenectomy of 0.58%.134 Again, this was

associated with a distal transverse colon or splenic flexure primary and increased the length of hospital

stay by 37.4%. It also increased the probability of perioperative death to 40%. In a large study using the

National Inpatient Sample database reviewing 975,825 patients undergoing colectomy between 2006

and 2008, the rate of splenic injury was 0.96%, 84.75% of which cases were treated with total

splenectomy, with the majority of remainder being treated by splenorrhaphy (13.6%).135 Factors

independently associated with splenic injury included, not unexpectedly, transverse, left or total

colectomy, but also open operation, malignant tumor, diverticulitis, teaching hospital status, peripheral

vascular disease, and emergent admission. Other studies have also found a lower incidence of splenic

injury in laparoscopic versus open colonic resections and to what extent this is attributable to technical

differences (e.g., better visualization laparoscopically in dissecting the splenic flexure) or to patient

selection remains to be defined.

The primary teaching point regarding iatrogenic injuries is that the best way to preserve the spleen is

not to damage it in the first place. This requires caution in mobilizing tissue in and around the spleen as

well as visual inspection of the attachments of the spleen prior to blunt mobilization. Whenever

possible, the spleen should be attempted to be preserved to decrease the risk of postsplenectomy sepsis.

DIAGNOSTIC SPLENECTOMY

2010

One indication for splenectomy is for diagnosis in an otherwise asymptomatic patient. The situation in

which splenectomy may be needed to make a diagnosis includes when a dissecting mass lesion is seen

within the spleen on CT scan, ultrasound, or MRI scan for which a definitive diagnosis cannot be made

radiographically. Another example is when patients have either palpable spleens on physical

examination or enlarged spleens by scan and otherwise have no clear diagnostic disorder. Table 73-9

lists the final pathology diagnoses in spleens removed for these two indications over a 10-year period in

two major academic medical centers.24 In that series, a total of 122 diagnostic splenectomies were

performed, 52 of which were for a splenic mass and 41 for splenomegaly with no other clear diagnosis.

An additional 29 were done to further characterize a known hematologic malignancy.

For the patients who have an isolated splenic mass, 60% turned out to be malignant lesions and 40%

turned out to be benign lesions (Table 73-9).24 The majority of the malignant lesions were lymphoma

with another large group being metastatic carcinomas including some in which the primary diagnosis

had not been made previously. There were two patients with metastatic sarcoma to the spleen. In the

benign diagnoses, more than half were cysts and there were also splenic hamartomas and splenic

hemangiomas. In a recent series of patients undergoing splenectomy at Memorial Sloan-Kettering

Cancer Center for lesions identified on imaging, the incidence of malignancy in the splenectomy

specimen was 63% (93 of 148 cases).136 The most common malignant pathologies were ovarian cancer,

melanoma, and colorectal cancer. Prior history of cancer was the only independent predictor associated

with malignant histology in the spleen specimen.

Table 73-9 Final Pathologic Diagnoses in 122 Spleens Removed for Diagnostic

Purposes

In terms of diagnosis of an isolated splenic mass, the majority of these lesions could have been

diagnosed by doing a fine needle aspiration biopsy. Certain of these lesions such as the cystic lesions or

the hemangiomas would have classic appearance on gadolinium enhanced MRI scan and it is another

imaging modality that could be utilized to sort out mass lesions without tissue biopsy. Although there

may be some hesitation to do fine needle aspiration biopsies on splenic lesions, due to the risk of

bleeding for most mass lesions this would have made the diagnosis and with the exception of splenic

hemangiomas essentially all of these lesions could be aspirated without any significant consequence.

The second diagnostic indication for splenectomy is unexplained splenomegaly. In this series over 10

years there were 41 cases, or 4 cases per year at these two hospitals in which a massively enlarged

spleen was removed purely for diagnosis.24 The majority of these (58%) turned out to be lymphoma.

The remaining 42% were split relatively evenly between benign lymphoid proliferation, benign vascular

2011

lesions, granulomatous disease, as well as splenic infarction and hemorrhage. The role of fine needle

aspiration and other percutaneous biopsy for splenomegaly is quite limited as there is considerable risk

of bleeding and this form of biopsy would generally be low yield in terms of establishing a diagnosis for

this indication.

Another type of diagnostic procedure would be a staging laparotomy for Hodgkin disease. Discussion

of this procedure is largely of historical interest as it has limited use in today’s current practice in

treating this form of lymphoma. A standard practice for pathologic staging between 1960 and 1990 was

performance of a staging laparotomy in most patients with Hodgkin disease. The reason to perform this

invasive procedure was based on reports that laparotomy altered the clinical stage of disease in

approximately 35% of patients and would impact on therapeutic management. Staging laparotomy was

typically performed via an upper abdominal midline incision.137 This included exploration of the entire

abdomen for any abnormal lymph nodes including nodes identified by lymphogram. Even if no

abnormalities were found, multiple tissues were removed for pathologic assessment. This included

removal of the spleen, bilobar hepatic wedge resections, and bilobar hepatic core biopsies, and multiple

lymph nodes samplings.

There are several reasons why the incidence of performing staging laparotomy has decreased over the

past 10 to 15 years,138 and the primary reason is that it does not alter treatment of Hodgkin disease

based on results of recent clinical series. The treatment of patients with stage IB, IIB, IIIB, IVB, IIIA, and

IVA Hodgkin disease almost always involves systemic chemotherapy. The only patients who could

theoretically benefit from staging laparotomy at present are patients with stage IA or IIA Hodgkin

disease who typically may receive treatment with radiation therapy. Even in this subgroup of patients,

there is a trend toward not performing staging laparotomy. First, many oncologists use combination

chemotherapy even for early-stage disease. Second, for patients who were treated with radiation

therapy alone for stage IA and IIA disease, it has been demonstrated in several recent clinical series that

ultimate outcome is equivalent whether these patients undergo staging laparotomy or whether they are

treated up front with radiation therapy.139,140 The reason is that if these patients recur outside of the

radiation field during long-term follow-up, they can frequently be salvaged with systemic

chemotherapy. Third, performance of staging laparotomy is obviously a major abdominal operation

with potential for morbidity and also the reality that treatment of Hodgkin disease will be delayed

typically between 4 and 6 weeks. Finally, there are data that patients who survive Hodgkin disease and

receive combination chemotherapy are at increased risk for the development of a secondary malignancy

that is primarily acute, non–lymphocytic leukemia (ANLL).141,142 In some series, the risk of developing

ANLL is increased up to 10-fold in patients who have undergone splenectomy as part of their staging

work-up for Hodgkin disease compared with patients undergoing similar chemotherapy regimens who

did not undergo splenectomy. For all of these reasons, this procedure, which accounted for a large

number of the splenectomies performed in major tertiary referral centers and cancer centers, is rarely

performed at the present time.

VASCULAR DISORDERS OF THE SPLEEN

Vascular problems with the spleen that can lead to splenectomy include both the venous and arterial

problems. The most common situation would be splenic vein thrombosis and splenectomy in this setting

is curative for the patient. Splenic artery aneurysms are one of the more common visceral aneurysms

and also can be an indication for splenectomy.

Splenic Vein Thrombosis

Splenic vein thrombosis is an unusual cause of upper gastrointestinal hemorrhage that can be cured by

splenectomy. The pathophysiology of this disease is an isolated thrombosis of the splenic vein as it

travels along the posterior pancreatic body and tail. The splenic venous outflow is then diverted to the

short gastric vessels as collateral venous outflow channels. This increased flow via the short gastric

veins leads to a high pressure with a dilatation of the submucosal venous plexus primarily in the gastric

cardia and fundus with eventual development of gastric varices.143

The cause of the splenic vein thrombosis does not involve any pathology of the spleen, but rather

typically pathology of the pancreas and possibly the stomach. Pancreatitis or pancreatic pseudocyst is

the cause of splenic vein thrombosis in more than 50% of patients in most series. Pancreatic carcinoma

with direct invasion and infiltration of the splenic vein is the second most common cause. Other unusual

2012