Discussion
Single-port laparoscopic ovarian cystectomy appears to be a promising minimal invasive technique offering the advantages of fast recovery, less trauma, and superior cosmetic outcome. On the other hand, the safety of this technique with respect to aspects of damage to ovarian reserve has been questioned. Until now this relevant issue has been poorly investigated, because of difficulties in assessing ovarian reserve after this kind of surgery in combination with the small number of study subjects and short follow-up intervals.
The presence of an ovarian cyst may distort and damage the adjacent healthy ovarian tissue but the laparoscopic stripping of ovarian cysts may further worsen ovarian reserve ,even if performed by experienced surgeons, through at least three ways: (i) the accidental removal of healthy ovarian cortex near the cyst’s capsule (ii) the thermal effect of diathermy coagulation of small bleeding vessels on the stripping area with consequent vascular compromise and (iii) a surgery-related local inflammation22-24.
In single-port laparoscopy (SPL) surgeons often experience difficulties in handling their instruments due to the unsatisfactory surgical plan. All instruments are placed in parallel, bump each other for targeting procedures and also are in line with the vision25. Nevertheless, the default of triangulation could limit the traction and counter traction needed for some ovarian cysts (endometriomas). It is argued that these limitations make the SPL ovarian cystectomy more technically demanding and difficult than conventional MPL and may cause more negative impact on preserving the ovarian function after laparoscopic ovarian cystectomy16. Our results have highlighted the fact that while total operative time and blood loss increased using SPL versus MPL ovarian cystectomy, there is not a remarkable difference in hospital stay and in reduction of postoperative AMH between SPL ovarian cystectomy and conventional MPL approach.
In our opinion the development of a new surgical approach should always be compared to the conventional treatment. The majority of studies did not display a remarkable difference in reduction of postoperative AMH between SPL ovarian cystectomy and conventional MPL approach13-15.
It seems that besides the number of laparoscopic ports there are several factors like histological type of cyst (endometriotic cysts or non-endometriotic cysts), the hemostatic approach (coagulation, suturing), location of cyst (unilateral or bilateral), cyst size that affect postoperatively the ovarian function15. During cystectomy, it is not always easy to identify and separate the cleavage plane between the cyst wall and adjacent ovarian cortex tissue due to fibrotic adhesion. Cystectomy using the stripping technique usually leads to removal of normal primary follicles and damage of ovarian reserve. Furthermore, bipolar coagulation at seriously bleeding sites close to ovarian hilus also leads to destruction of the ovarian blood supply and reduced ovarian reserve19.
The major limitations of this meta-analysis is that the strength of evidence is low because of quality issues of available studies and the heterogeneity in ovary cyst type of four included studies. Currently the evidence is not strong enough to recommend or discourage the use of single-incision laparoscopy over conventional laparoscopy. The available literature suggests that the risk of complications is similar between procedures. Further randomized studies with larger sample sizes are required to demonstrate in which degree all these factors contribute to the loss of the ovarian reserve.