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laparoscopic procedures have been proposed to reproduce the surgical steps of open surgery and decrease morbidity , postoperative pain , and hospital stay .
laparoscopic surgery for adrenal tumors was firstly reported in 1992 by gagner et al . who used the transperitoneal approach in three patients .
the benefits of laparoscopy on postoperative pain , cosmesis , hospital stay , and convalescence are widely recognized .
the upper limit of tumor size for laparoscopic surgery was thought to be 6  cm , for two main reasons : ( i ) the technique to remove a large tumor by laparoscopy is difficult ; ( ii ) large tumors have higher possibility of malignancy .
but , there are some series of reports that laparoscopic surgery of the large pheochromocytomas was safe and effective . from 2009 to 2014
, we evaluated 110 cases of adrenal diseases including the diameter of > 5  cm adrenal tumor who underwent laparoscopic adrenalectomy .
the procedures are usually performed with the patient in a flank position ( 90 ) with the operating table fixed and then we elevated and exposed the surgical area between the costal margin and the iliac crest , and a 2  cm skin incision was made on the middle axillary line above the iliac crest . the fascia was exposed and incised over the same length , the muscle layers were divided bluntly , and the peritoneum was free from the abdominal wall by a finger dissection . inserting the 10  mm trochar , co2 was insufflated to a maximum pressure of 2.0  kpa , and then the laparoscope was introduced .
the peritoneal sac was mobilized medially to allow for the introduction of two additional trochars on the anterior axillary line at the level of the two preceding trochars .
gerota 's fascia was identified and opened to expose the upper pole of the kidney and the adrenal gland .
statistical analysis used two - sample wilcoxon rank - sum ( mann - whitney ) test via stata7 software .
p value less than 0.05 was considered statistically significant . from 2009 to 2014 , 110 patients diagnosed with adrenal benign tumors by ct scan were treated by retroperitoneal laparoscopic adrenalectomy at huashan hospital of fudan university , china .
the patients were analyzed retrospectively , including 65 on the left , 39 on the right side , and 6 on both sides , in 43 men and 67 women aged 2279 ( mean 50 ) years .
the laparoscopic approach has been the procedure of choice for surgery of benign adrenal tumors , and the upper limit of tumor size was thought to be 6  cm .
109 cases were successfully completed , but one case was converted into open surgery because the bleeding was out of control ( pathology diagnosed adrenal cortical carcinoma ) . the mean operating time and
intraoperative blood loss were 102.536 ( 35327 )  mins and 81.454 ( 5700 )  ml , respectively .
cortical adenoma was the most common pathology ( 62.727% ) , followed by cortical hyperplasia and myelolipoma ( 9.091% ) , pheochromocytoma ( 6.364% ) , cyst ( 3.636% ) , adrenal cortical carcinoma ( 2.727% ) , lipoma ( 1.818% ) , neurofibroma ( 0.909% ) , spindle cell tumor ( 0.909% ) , cystic tumor ( 0.909% ) , inflammatory mass ( 0.909% ) , and lymphangioma ( 0.909% ) ( table 2 ) .
we divided all patients into 3 groups which were benign tumor , pheochromocytoma , and malignant tumor groups and analyzed the average diameter , operating time , and intraoperative blood loss of each group .
based on pathologic specimens and ct scans , the tumor average diameter was 2.688  cm ( 0.66 ) .
the average diameters of benign tumors , pheochromocytomas , and malignant tumors were 2.607  cm ( 0.66 ) , 3.214  cm ( 23.5 ) , and 3.5  cm ( 3 - 4 ) , respectively .
the malignant tumors were bigger than the other tumors but without statistical significance ( p > 0.05 ) .
one case was converted into open surgery and the operating time was 327  mins because the bleeding was out of control ( pathology diagnosed adrenal cortical carcinoma ) .
the average operating times of benign tumors , pheochromocytomas , and malignant tumors were 97.62  mins ( 35280 ) , 140.14  mins ( 90205 ) , and 178.67  mins ( 60327 ) , respectively .
the intraoperative blood loss of benign tumors , pheochromocytomas , and malignant tumors was 8  ml ( 8400 ) , 85.71 ( 0400 ) , and 0  ml , respectively .
the intraoperative blood loss and average operating time of pheochromocytomas were significantly more than the benign tumors ( p < 0.05 ) , but malignant tumors between benign tumors or pheochromocytomas were without statistical significance ( p > 0.05 ) ( figure 1 ) .
the choice of the surgical approaches of laparoscopic adrenalectomy depends on the operators ' habits and experience .
the intraoperative blood loss of pheochromocytomas was significantly more than the benign tumors ( p < 0.05 ) .
first , control the blood pressure before operation by cardura . if it is necessary , use  receptor blocker .
second , the operators should carefully read the ct and mri imaging data and ensure the location of the tumor and the relationship with the surrounding organs and tissues .
third , during the operation , clamp the fat around adrenal gland gently and cut off the small blood vessel by ultrasonic knife to decrease bleeding to maintain visual field .
the vital management is to dissociate adrenal central vein enough , with 3 titanium clips ligation .
if the vessel is thick , using the ham - o - lock ligation is necessary . with regard to the diameter
> 5  cm of adrenal tumor or large pheochromocytomas , we prefer transabdominal approach .
compared to retroperitoneal la , transabdominal approach is risky and can injure intestine , liver , spleen , and other adjacent organs but has the advantages of the obvious anatomical landmarks , wider operation space , and more convenience during the operation .
the large adrenal tumors have higher malignant incident rate , and most of the researchers do not recommend resecting the malignant tumors by laparoscopic adrenalectomy because those are large , rich in blood supply , with thin envelope surrounding tissue invasion . in addition , laparoscopic clamping separation may lead to tumor rupture , local recurrence , or trochar implant .
some researchers held negative attitude of laparoscopic operation for larger adrenal tumors . nevertheless , confirming the adrenal malignant tumors is difficult by imaging . under imaging ,
the malignant tumors present irregular boundary , local invasion , and uneven and high density , and so do benign tumors .
sturgeon et al . discovered more malignant incidence rate of the large adrenal tumor ( < 4  cm = 5% , 4  cm = 10% , and 8  cm = 47% ) .
our data showed three malignant tumors were 3  cm , 3.5  cm , and 4  cm , respectively ( < 4  cm = 2.22% , 4  cm = 5% ) .
if we only consider the tumor size as the surgical approaching standard , many patients will undergo unnecessary open operation .
and lombardi et al showed 3-year disease - free survival rate and local recurrence rate were similar to open operation .
as for trocar metastasis , it is a rare complication of laparoscopic operation [ 7 , 8 ] .
our data showed that the average diameter , operating time , and intraoperative blood loss of malignant tumors were not significantly different to pheochromocytomas and benign tumors ( p > 0.05 ) indicating that the laparoscopic operation of adrenal malignant tumor is safe . but for those tumors invading surrounding tissue and blood vessels , they are difficult to control and separate , when patients have serious bleeding circumstances , we should seize the opportunity to convert into open operation . in view of this , implementing laparoscopic operation of adrenal malignant tumors is not the contraindication . but before being widely carried out , multicenter prospective controlled trials on laparoscopic and open radical adrenalectomy of malignant tumors are necessary .
objective . to evaluate the indication and the clinical value of laparoscopic adrenalectomy of different types of adrenal tumor 
 . methods . from 2009 to 2014 , a total of 110 patients were diagnosed with adrenal benign tumor by ct scan and we performed laparoscopic adrenalectomy . 
 the laparoscopic approach has been the procedure of choice for surgery of benign adrenal tumors , and the upper limit of tumor size was thought to be 6  cm . results . 
 109 of 110 cases were successful ; only one was converted to open surgery due to bleeding . 
 the average operating time and intraoperative blood loss of pheochromocytoma were significantly more than the benign tumors ( p < 0.05 ) . 
 after 3 months of follow - up , the preoperative symptoms were relieved and there was no recurrence . 
 conclusions . 
 laparoscopic adrenalectomy has the advantages of minimal invasion , less blood loss , fewer complications , quicker recovery , and shorter hospital stay . 
 the full preparation before operation can decrease the average operating time and intraoperative blood loss of pheochromocytomas . 
 laparoscopic adrenalectomy should be considered as the first choice treatment for the resection of adrenal benign tumor .