Abstract
Uterine fibroids or leiomyomas are the most common benign gynaecological tumours; up to 25–30% of women may be diagnosed with fibroids during their lifetime [1]. Women with uterine fibroids may be asymptomatic, or they may present with menstrual symptoms such as menorrhagia and dysmenorrhoea, pressure symptoms, infertility, recurrent miscarriage or complications during pregnancy like red degeneration.
7.1 Introduction
Uterine fibroids or leiomyomas are the most common benign gynaecological tumours; up to 25–30% of women may be diagnosed with fibroids during their lifetime [1]. Women with uterine fibroids may be asymptomatic, or they may present with menstrual symptoms such as menorrhagia and dysmenorrhoea, pressure symptoms, infertility, recurrent miscarriage or complications during pregnancy like red degeneration.
The management of uterine fibroids depends on the presenting symptom, number, size and location of the fibroid within the uterus and the patient’s fertility wish. The risk of malignancy is extremely rare in slow-growing fibroids. However, in suspiciously fast-growing fibroids, the risk of malignancy can be up to 0.27% [2].
Small asymptomatic fibroids are usually managed expectantly. However, for those with large symptomatic fibroids, surgery may be required. In those who have completed childbearing, hysterectomy may be appropriate, but for women who still wish to conceive in the future, myomectomy could be considered. Myomectomy can be performed via hysteroscopy, laparoscopy or laparotomy (open myomectomy); the choice being primarily dependent on the location of the fibroids, as well as on the size, number, available expertise and facilities.
7.2 Open Myomectomy
7.2.1 Why Laparotomy?
Up till now, increasing number of intramural and subserosal fibroids are being removed laparoscopically, for several reasons [3]. It is minimally invasive with reduced need for postoperative analgesia and hospital stay. It is often quoted that recovery following laparoscopic myomectomy is speedier than open myomectomy. Whilst this is still true, the difference is becoming less significant as women after open myomectomy in many modern units are being mobilized earlier, allowed to eat early and discharged home after 24–48 hours. In recent years, it appears that open myomectomy is regaining favour in women who wish to conceive again, as the risk of scar rupture during pregnancy following laparoscopic myomectomy is perceived to be higher than that after open myomectomy.
In addition, open myomectomy remains necessary in several situations, such as a huge subserosal or intramural fibroids, multiple fibroids or when entry into the uterine cavity is expected [4]. Open myomectomy is also preferred in cases with vascular fibroids or fibroids with suspected sarcomatous change, and in women who would not wish to consider blood transfusion (Jehovah’s witness).
7.3 Preoperative Counselling and Preoperative Preparation
Whilst many aspects of preoperative counselling and preparation apply to both laparoscopic and open myomectomy, given that the size of the fibroid or number of fibroids are often larger in the case of open myomectomy, detailed counselling on the possible (immediate and delayed) complications of myomectomy and preoperative preparations to minimize the various complications are particularly important.
7.3.1 Preoperative Counselling
Women considering myomectomy should be fully counselled regarding the various possible risks, including anaesthetic complications, infection, visceral injury, bleeding, blood transfusion, hysterectomy (~1%), recurrence and adhesion formation.
7.3.2 Preoperative Preparation
Women undergoing myomectomy should have their baseline haemoglobin level checked. Anaemia if present should be treated before the planned surgery as it is known to increase surgical morbidities. The anaemia can be corrected with oral iron supplements or blood transfusion depending on urgency. The use of hormone treatment to suppress menstruation for a few months prior to surgery may be considered if there is significant menorrhagia. Cross-matching of blood should be performed if excessive blood loss is anticipated. Bowel preparation is not routinely necessary but may be considered in those with high risk of intra-abdominal adhesions. Prophylactic measures against thromboembolism such as elastic stockings or subcutaneous heparin should be undertaken.
7.3.3 GnRH Analogues
Prior to surgery, a GnRH agonist can be used to induce amenorrhea, which can improve preoperative haemoglobin as well as reduce intraoperative blood loss [5]. Moreover, it can shrink the fibroid and uterine size and may, in some cases, enable a pfannenstiel incision to be made instead of a midline incision.
Yet many surgeons do not advocate the routine use of GnRH analogues, for many reasons. Firstly, it makes the surgical planes less distinct and thus more difficult for surgeons to enucleate the fibroids during the operation. This may then increase the difficulty of the operation and prolong the operative time [4]. Secondly, some surgeons believe that it causes small fibroids to shrink (temporarily) and so become more difficult to be detected during the operation, which may therefore increase the recurrence rate. In addition, GnRH agonist therapy is associated with unwanted side effects and increases the overall cost of the treatment.
7.3.4 Ulipristal Acetate (UPA)
Ulipristal acetate (UPA) is a selective progesterone receptor modulator (SPRM) and has been recently introduced in the treatment of uterine fibroids [6]. It has been shown to be effective in reducing menorrhagia and fibroid size and may be an alternative to preoperative GnRH agonist therapy. There is increasing use of UPA for uterine shrinkage before surgery nowadays [6, 7]. However, it is unclear if it makes the enucleation of the fibroid more difficult, as in the case of GnRH agonist therapy.
7.3.5 Preoperative Fibroid Mapping
It is useful to ascertain the number and location of fibroids before the operation. This can usually be performed with a careful ultrasound examination. A 3D saline infusion sonography may from time to time provide additional information. In more complex cases, magnetic resonance imaging may be needed [8]. Fibroid mapping before the operation allows better surgical planning, including a decision regarding the choice of laparoscopic or open myomectomy, whether special equipment is required and the likely operation time.
7.4 Operation Techniques
7.4.1 Microsurgical Principles
It is important to follow microsurgical techniques during open myomectomy. Minimal handling of tissue with meticulous haemostasis throughout the operation is crucial. Atraumatic instruments should be used when handling tissue. Moreover, the operative field should be kept moist with continuous irrigation [4].
7.4.2 Abdominal Incision
A suprapubic transverse pfannenstiel incision is sufficient in most of the cases. It is not only aesthetically acceptable to the patient but is also shown to be associated with less postoperative pain and quicker postoperative recovery. Even when the size of the fibroid uterus means that it is well above the umbilicus, it is often possible to shrink it down to the level of the umbilicus with GnRH analogues [9], so that a suprapubic transverse pfannenstiel skin incision is sufficient. A midline incision is required only in cases where the uterine size remains huge despite GnRH down-regulation, and when difficulty with access such as those with obesity or dense adhesion is encountered. When there is already an existing midline incision scar, it is still preferable to perform the laparotomy via a new pfannenstiel incision.
7.4.3 Reducing Blood Loss
Reducing blood loss is the most important aspect of myomectomy surgery. The risk of hysterectomy has been quoted to be 1–2%, and up to 20–30% of patients may require blood transfusion during the operation [10]. Many techniques for reducing blood loss are applicable to both laparoscopic and open surgery, while some methods are specific for open myomectomy.
7.4.3.1 Methods Specific to Open Myomectomy
Rubber Tourniquets
Tourniquets have been used to reduce the blood flow from the main feeding vessels. When a single tourniquet is used, the tourniquet is applied around the cervix to occlude both uterine arteries. When triple tourniquets are used, the ovarian vessels are occluded lateral to the ovaries [11]. The broad ligament is opened anteriorly with the bladder reflected. After the surgeon creates a small opening in the avascular leaf of the broad ligament on either side of the uterine isthmus superior to the uterine vessels, a rubber tourniquet can be threaded through the holes and tied anterior around the cervix at the level of the internal os to compress the uterine arteries. In addition, two further tubings can be threaded through the defect over the broad ligament and looped around the infundibulopelvic ligament lateral to the fallopian tube and ovaries to compress the ovarian vessels.
A recent randomized controlled trial (RCT) by Al et al. [12] involving 48 patients found no significant difference in the outcome of blood loss between triple and single uterine tourniquets (322 ± 223 vs. 426 ± 355 mL, p = 0.230) at open myomectomy. In another RCT, triple tourniquets have been shown to be effective in reducing bleeding and transfusion rates and appear to have no obvious adverse effect on uterine perfusion or ovarian function when compared to controls [13]. Some surgeons have used the Foley catheter as a tourniquet as it is easily available in theatres [14].
Bonney’s Myomectomy Clamp
Victor Bonney was the pioneer for open myomectomy, and modern myomectomy technique has changed very little since he described his technique in 1946. He developed a technique to reduce the blood supply to the uterus and fibroid by using a paracervical mechanical clamp also known as the Bonney myomectomy clamp [15]. This clamp is placed at the level of the cervix to temporarily compress the uterine arteries during the operation. It can be used in conjunction with rubber tourniquets to occlude the ovarian vessels. The ureters should be traced before applying the clamps. The clamps can be released every 15 minutes to reduce the chance of irreversible ischaemic damage.
Haemostatic Suture
A further advantage of open myomectomy over that of laparoscopic myomectomy is that haemostatic suture can be applied promptly in case of brisk bleeding from a major feeding vessel. Active bleeding can be controlled immediately with manual compression or the application of a clamp, followed by the application of an haemostatic suture. There is little doubt that effective haemostasis can be achieved more quickly during open myomectomy compared with laparoscopic myomectomy.
Uterine Artery Ligation
Uterine artery ligation involves the suturing of both uterine arteries. Its efficacy remains controversial. Sampaz et al. [16] showed that intraoperative blood loss was lower with bilateral ligation of the ascending branches of the uterine artery when compared to tourniquet methods during myomectomy. They found that the effect of ligation on haemorrhage continues in the postoperative period. Moreover, Helel et al. [17] performed an RCT to compare the effectiveness of preliminary uterine artery ligation versus pericervical mechanical tourniquet in reducing haemorrhage during myomectomy. Their study included a total of 103 patients undergoing myomectomy. The operative blood loss was found to be significantly less with uterine artery ligation than with tourniquet (434 vs. 823 mL, p < 0.001). The mean operation time (51 vs. 76 minutes, p < 0.001) and postoperative hospital stay (4.1 vs. 5.1 days, p < 0.001) were also significantly shorter than in the tourniquet group. Their study concluded that uterine artery ligation was more effective than pericervical tourniquet in reducing blood loss during abdominal myomectomy.
However, there are concerns that uterine artery ligation may adversely affect wound healing, compromise ovarian blood supply, cause intrauterine adhesions and affect endometrial function. Further studies are required to assess if these concerns are justified.
7.4.3.2 Methods Feasible for Both Laparoscopic and Open Myomectomy
Vasopressin Injection
Vasopressin is a potent vasoconstrictor. Vasopressin may be injected into the broad ligament close to the insertion of ovarian and round ligaments and also superficially into the capsule of fibroids before incision (Figure 7.1). In an RCT performed by Frederick et al. [18], vasopressin was effective in preventing blood loss and reducing the need for blood transfusion during myomectomy. Another RCT involving 52 patients [19] compared the efficacy of perivascular vasopressin and tourniquet in minimizing bleeding during myomectomy. Vasopressin resulted in less blood loss (mean 287.3 mL vs. 512.7 mL for tourniquet, p = 0.036). Six out of 26 patients in the tourniquet group lost more than 1,000 mL of blood, whereas all of the vasopressin subjects lost less than this amount (p = 0.023). Their study concluded that vasopressin prevented blood loss better than tourniquet use during myomectomy.
However, vasopressin may rarely cause severe hypotension, bradycardia and even death [20], especially when it is inadvertently injected intravascularly. It is wise to aspirate before injection of vasopressin to avoid direct injection of vasopressin into a blood vessel. It is contraindicated in patients with vascular and renal diseases. The usual dose is 6 IU, at a dilution of 1 IU/mL normal saline.
GnRH Agonists (Preoperative)
GnRH agonists may be used to prevent blood loss during myomectomy. An earlier meta-analysis of 26 RCTs on the use of GnRH agonist before surgery for fibroids (either hysterectomy or myomectomy) has shown a beneficial impact on blood loss as well as pre- and postoperative haemoglobin and haematocrit level [9].
Uterotonic Agents
Uterotonic agents are often used as first-line treatment during postpartum haemorrhage. Oxytocin is the most commonly used uterotonic agent, and oxytocin receptors have recently been demonstrated in fibroid uterus. Atashkhoei et al. [21] performed a double-blinded randomized controlled trial and found oxytocin safe and effective in decreasing blood loss during abdominal myomectomy. They randomized 40 women undergoing open myomectomy to the study group (with 30 IU in 500 mL normal saline given during myomectomy) and 40 women to the placebo group (pure normal saline given). The estimated intraoperative blood loss in the study group (189.5 mL) was significantly lower than in the placebo group (692.25 mL), p < 0.0001. They also found the need for blood transfusion was significantly lower in the study group. Blood transfusions were required for 3 (7.5%) women in the study group and 10 (25%) women in the placebo group.
Intravenous Tranexamic Acid
Intravenous tranexamic acid is an anti-fibrolytic agent commonly used to treat menorrhagia. In recent years, it has also been used to reduce blood loss during caesarean section. Wang et al. [22] have recently performed a meta-analysis of randomized controlled trials in assessing the efficiency and safety of tranexamic acid for reducing blood loss during open myomectomy. A total of four RCTs involving 328 patients were analysed. They found significant differences in terms of total blood loss, postoperative haemoglobin level, transfusion requirements and duration of surgery in those with tranexamic acid use when compared to those without. However, further high-quality RCTs are necessary to confirm the clinical benefit.
Uterine Artery Embolization
Preoperative uterine artery embolization (UAE) has been employed not only to shrink large fibroids but also to reduce blood loss during myomectomy. A retrospective study [23] showed a mean reduction of 77% in uterine volume and 46% in fibroid diameter among 20 patients who underwent open myomectomy after UAE. Whilst the results appeared encouraging, there are concerns regarding wound healing, ovarian blood supply and endometrial function, as in the case of uterine artery ligation.
Cell Saver
The use of autologous blood cell salvage has been suggested in women undergoing abdominal myomectomy. This can not only recycle the blood lost during the operation but also avoid the risks related to allogenic blood transfusion, including immunological reactions. Yamada et al. [24] found it useful in patients with heavy blood loss during open myomectomy. However, in a study involving 425 patients undergoing open myomectomy, Son et al. [25] suggested that routine use of cell salvage was not warranted. Cell salvage is not readily available in every unit and the set-up requires special expertise. It should be used in women who would not wish to consider blood transfusion (Jehovah’s witnesses).
Gelatine Fibrin Matrix
FloSeal® (FloSeal Matrix; Baxter Healthcare Corp., Fremont, CA) is a gelatin fibrin matrix with both a bovine-derived gelatin matrix component and a human-derived thrombin component [26]. It is biocompatible and is completely reabsorbed within 6–8 weeks, which is consistent with normal wound healing. It has been widely employed in various specialties for haemostasis [27]. We have also been using it for haemostasis after laparoscopic ovarian stripping for ovarian endometriomas. After application to the bleeding sites, the special particles of the FloSeal® Matrix will swell approximately 10–20% upon contact with blood and provide an additional compression effect. It can achieve haemostasis within 2 minutes at the site of action. It works well in both wet and active bleeding sites but must not be injected directly into vessels due to the risk of thromboembolism. Raga’s team have applied FloSeal® to the site of the uterine bleeding during myomectomy [28]. They found the use of FloSeal reduced haemorrhage during myomectomy. FloSeal® is particularly useful in situations when there is persistent oozing from serosal wound edge or suture holes, or when the bleeding occurs at locations difficult for suturing or diathermy, e.g. near the ureters following removal of a broad ligament fibroid.
7.4.4 Uterine Incision
7.4.4.1 How?
A serosal incision over the main bulk of the fibroid should be made. Incision with a scalpel is preferred to the use of diathermy to reduce the risk of subsequent scar rupture resulting from excessive diathermy. The incision is then extended towards the myometrium until the capsule of the fibroid is reached. The fibroid is then enucleated as described below.
7.4.4.2 Single versus Multiple Incision
If several fibroids are situated in close proximity, it may be possible to make a single incision to remove the multiple fibroids. Whilst it is desirable to reduce the number of incisions, this should not be done without due regard to other surgical factors. An anterior fibroid should be removed via an anterior incision and a posterior fibroid should be removed via a posterior wall incision to avoid unnecessary entry into the uterine cavity, which would increase the risk of subsequent scar rupture. The incision should be made over the maximal bulge of the fibroid. With open myomectomy, there is more flexibility in choosing a vertical, transverse or horizontal incision, to avoid getting too close to the cornual region (insertion of the fallopian tube), uterine vessels and bladder. In contrast, with laparoscopic myomectomy the choice of the incision is often influenced by how the surgeon is used to suturing in a particular position. Some surgeons prefer a transverse incision to avoid cutting through arcuate vessels, as this may reduce blood loss and allow better myometrial healing. In the case of a fundal fibroid, anterior incisions are preferred as posterior incisions are associated with an increased risk of adhesion formation. In the past, some surgeons would insist on making a single anterior incision regardless of the number of fibroids present, on the basis that adhesion formation after myomectomy is more common after a posterior wall incision; however, this is no longer regarded as necessary.
7.4.5 Enucleation
Once incision has been made, the fibroid capsule or the fibroid myometrial plane should be identified. Enucleation of the fibroid may be facilitated by applying traction to the fibroid using a myoma screw, separation of the fibroid from the capsule with a MacDonald dissector and the application of a twisting force towards the end of the enucleation process. During enucleation, bleeding from the feeding vessels can be controlled with diathermy or sutures. Excessive diathermy should be avoided as it may lead to poor healing of the myometrium and an increased risk of future uterine rupture. After enucleation, the uterine cavity should be checked for integrity. It is not always necessary to enucleate all fibroids; multiple small intramural fibroids that do not distort the uterine cavity may sometimes be left behind. In case the fibroid myometrial plane is difficult to distinguish, one should be beware of the possibility of adenomyosis and decide if the procedure should continue [29].
7.4.6 Closure
Once the fibroids are removed, it is important to carefully close the uterine defect and to ensure that any dead space is obliterated from the bottom up, using sutures to achieve good apposition and effective haemostasis. Careful reconstruction of the uterine wall is essential as it reduces the risk of scar dehiscence during a subsequent pregnancy. The uterine defect should be closed in two to three layers depending on the depth of myometrium. In closing a large defect, interrupted sutures may be considered for the deep, innermost layers. Several interrupted sutures may be placed along the entire length of the defect in the uterine wall; they are held separately by artery forceps but not tied until after all the sutures have been placed (Figures 7.2 and 7.3). The assistant is then asked to use fingers to bring the opposing edges of the uterine wall together to reduce tension on the sutures when the knots are tightly tied, one after the other (Figure 7.4). In this way, it will not only ensure optimal closure of any dead space but also reduce the chances of the sutures cutting through the myometrium when they are tightened and tied (Figure 7.5).
Figure 7.3 The second layer of closure: interrupted stitches are held with artery forceps.
Figure 7.4 An assistant brings the uterine walls together for better tissue approximation and to reduce the tension when the interrupted sutures are tied.
