Introduction
Laparoscopic surgery
Laparoscopic surgery is a noteworthy diagnostic and therapeutic surgical procedure, which is proposed as the gold standard method since the first successful laparoscopic cholecystectomy in 1987. Laparoscopy is among minimal access techniques, reduces the traumas resulted from the surgical interventions and reveals considerable therapeutic outcomes. Various advantages of this method over the conventional open surgeries have led to the worldwide popularity of this procedure for treating numerous organs. Small incision is the major benefit of laparoscopy, which results in lower pain and recovery time, and small post-operative scars. Reduced hemorrhage, early mobilization of the patients, lower hospital staying, and minimal exposure of internal organ which reduce the risk of various infections, are other considerable features of laparoscopy (1).
These days, due to significant improvements in performance of laparoscopy, it is used for different indications including cholecystectomy, appendectomy, vagotomy, nephrectomy, herniorrhaphy, hysterectomy, ovarian cystectomy, pancreaticoduodenectomy, rectopexy, and etc (2).
Different risk factors might adversely affect the laparoscopic operation and outcomes based on the type of laparoscopy and the involved organ.
Major complications of each laparoscopic operation can be studied in different groups including peritoneum access complexity, complications following pneumoperitoneum, and the complications of the procedure.
Pneumoperitoneum
Because of the requirement for adequate visualization to increase the possibility of enhanced performance and organ manipulating during the surgery, pneumoperitoneum is necessary in every laparoscopic surgery. Creation of pneumoperitoneum using carbon dioxide (CO2) is one of the major aspects of the surgery that might lead to the various physiological complications. The creation of pneumoperitoneum results in increased pressure of the intra-abdominal, raised diaphragm, downturned functional residual capacity (FRC), and the induced hypoxemia which might lead to pulmonary changes and should be managed during the surgery (3). Reported cardiovascular changes include elevated the systemic vascular resistance, arterial and central venous pressures, decreasing the venous return, and cardiac index (4).
Based on studies, various cardiovascular and cardiopulmonary changes occur during the laparoscopy which might be the consequences of patient position, CO2 absorption, ventilation, and operation times and method (5).
It has been recommended that additional pre-operative considerations should be undertaken in patients who are pregnant, obese, or those with previous operations or cardiopulmonary problems.

Splenomegaly
Splenomegaly is a disease condition resulted from different factors and disorders including infections (infectious mononucleosis, viral hepatitis, septicemia, typhoid, cytomegalovirus, toxoplasmosis, tuberculosis, HIV, leishmaniasis, malaria), hematological conditions (myelofibrosis, chronic myeloid leukemia, lymphoma, leukemia, congenital causes), inflammations and malignancies and etc. The etiology of splenomegaly is different between developing and developed countries. The definitions of the splenomegaly varies according to every article but majorly, spleens more than 1.5kg weight or 10 times larger than normal size are proposed as splenomegaly, however, the exact size of the spleen is hard to be assessed (6). Before deciding for splenectomy, the occurrence of splenomegaly should be accurately diagnosed based on the patients’ clinical features, different experiments, and splenic biopsy.
Computed tomography scans and ultrasound procedures are helpful in providing the more accurate evaluation of the spleen size for massive splenomegaly.

Splenectomy
Splenectomy is a diagnostic and therapeutic method, which can be used for removing the defected spleen. The occurrence of spleen failures might be resulted conditions such as refractory, relapse, or chronic diseases, which have failed pharmacotherapy responses or other treatments. Hemolytic anemias, hemolytic purpuras, secondary hypersplenism, and other primary hematologic disorders might lead to the spleen damages and eventually complete splenectomy (7).
Splenectomy in patients with hematologic disorders has been previously reported as a procedure with post-operative morbidity and mortality risk of almost 52% and 9%, respectively. Septic complications were proposed as the major causes of post-splenectomy mortality. The frequency of post-operative complications had been suggested to be higher in patients with spleen larger than 2000 gr (8). Due to the lower prevalence of spleen disorders which need splenectomy surgery it is not easy to perform clinical trials. In various studies, the properties and benefits of open splenectomy have been compared with laparoscopic method. The extraction of the spleen is a complex issue, which led to various controversies about the suitability of laparoscopy for this purpose. According to studies, splenectomy might reveal some major therapeutic efficacies (reversing the cytopenia associated with hypersplenism) in addition to diagnostic benefits (9).

Laparoscopic splenectomy
The first laparoscopic splenectomy was achieved successfully in 1991 by Delaitre et al. which increased the prevalence of using this method in comparison with conventional open surgeries (10). Previously, splenomegaly was known as the contraindication of laparoscopic splenectomy. In recent years, due to significant improvements of the clinical procedures, laparoscopy has shown outstanding achievements in splenectomy of patients with splenomegly (11,12).
Idiopathic thrombocytopenic purpura (ITP) not assisted with splenomegaly and patients who are young with normal spleen size are the major indications of laparoscopic splenectomy. Based on some studies about the methods used for the treatment of idiopathic thrombocytopenic purpura (ITP), the laparoscopic splenectomy has been proposed as the gold standard method compared to the open splenectomy. In one study on the ITP, the preference of laparoscopy was independent from parameters including patient’s age, sex, comorbidity, and the size of the spleen. Short hospitalization after the laparoscopy and more quick mobilization of the patients were reported as the major advantages of laparoscopy in ITP patients. In another study, patients`age and spleen size were considered as the prognostic parameters of the laparoscopic results (9,13,14).
Enlarged spleens or massive splenomegaly need more sophisticated methods for splenectomy. Targarona et al. evaluated the effect of spleen size on post-operative outcomes of laparoscopy and open surgery. In this regard, the preoperative pneumococcal vaccine and antibiotic prophylaxis reduced the risk of different possible infections. It is proposed by Targarona et al. that spleens close to anterior iliac spine or those which surpass the midline, are suitable cases for open surgery, but patients with mobile inferior splenic pole and a distensible abdomen are acceptable cases for the laparoscopic method (15).
Results obtained by another study suggested that laparoscopic splenectomy reveals similar results regarding the post-operative morbidity, hospitalization, and the transfusion requirement rate in patients with larger spleens compared with those with normal size spleen (16).
Although laparoscopy revealed higher efficacy over the open surgery regarding the splenectomy of patients with hematological diseases with normal or relatively large spleens, controversial and inconsistent results have been obtained based on different studies about the efficacy of laparoscopy in massive splenomegaly (over than 1000 grams in weight) (17). One study revealed almost 33% morbidity rate during massive laparoscopic splenectomy and proposed the spleen size as the significant prognostic variable of morbidity and conversion rate to open surgery. Due to the reduced abdominal size in patients with massive splenomegaly during the surgery and lower possibility for manipulating the organ, the conversion of laparoscopy method to open surgery might happen. Bleeding was proposed as one of the major complications of the laparoscopy of massive splenomegaly cases (18). Almost 10-fold increase in post-surgical morbidity rate with longer hospitalization has been reported in 2004 as results of the laparoscopy of patients with massive splenomegaly (19). In contrast to the mentioned study, others have indicated no limitation for performing laparoscopy in patients with significantly massive splenomegaly. It is also indicated that laparoscopy appears to be associated with less blood loss, transfusion necessity, hospitalization, revision, and death (20). Hand-assisted laparoscopic approach is another type of laparoscopy that might be applied for the supra-massive splenomegaly (19,21).
In Table 1, information of recent trials, which have compared the efficacy of laparoscopy and open surgery for splenectomy of patients with massive splenomegaly secondary to various hematological diseases, ITP, and other disorders are summarized.
 According to the study of Vecchio, spleen size and splenectomy surgery can be suggested as risk factors for portal vein thrombosis as a post-splenectomy complication. Although the occurrence of this complication is rare, it should be diagnosed and managed carefully by accurate follow-up. In the study of Vecchio et al., no significant difference was observed in the frequency of portal vein thrombosis between laparoscopy and open surgery and heparin was suggested to apply for all the patients who have been under the splenectomy (22,23).
Sickle cell disease (SCD) is another disorder that usually represents with spleen involvement and finally the patients` splenomegaly with severe adhesion. Laparoscopy has been proposed as a preferred method, which can be performed concomitantly with cholecystectomy in SCD patients. Laparoscopic splenectomy in SCD patients has revealed reduced transfusion requirement rate and other post-operative complications including acute chest syndrome (24). Articles studied the efficacy of different methods in splenectomy, all have suggested laparoscopy as the preferred method to open surgery (24, 26). According to Maurus et al, spleen size should not be the only considered parameter while choosing the proper splenectomy method; the possibility of conducting laparoscopy splenectomy should be evaluated as an important priority regarding to the patients` conditions and history (25). In various studies on splenomegaly secondary to different hematological disorders, laparoscopy have been proposed as a technically demanding procedure due to reduced peritoneal cavity, decreased ability for organ moving, and increased adhesion of the organ as a result of spleen enlargement (27). In these studies, laparoscopy can be associated with higher rate of conversion to open surgery, bleeding, operation duration, and major post-operative complications if not be managed via skilled experienced surgeon (27,29,30).
 
Conclusion
According to articles and different conducted trials, it is not easy to propose an evidence-based management strategy for the splenectomy of patients with splenomegaly. Based on various studies, laparoscopy would be recommended as the preferred procedure even for patients with massive spelenomegaly, due to several advantages over other methods of the splenectomy. No significant differences have been observed between methods regarding the patients` bleeding and mortality rate. Further reliable trials are needed for obtaining more comprehensive evaluations of splenectomy method benefits.

Acknowledgement
We would like to thank Clinical Research Development Center of Ghaem Hospital for their assistant in this manuscript. This study was supported by a grant from the Vice Chancellor for Research of the Mashhad University of Medical Sciences for the research project as a medical student thesis with approval number of 910312.

 Conflict of Interest
The authors declare no conflict of interest.