Laparoscopic gynaecological surgery in the context of maintaining normal intracranial pressure

Abstract

A nulliparous patient in her early 20s was referred to a fertility specialist for fertility preservation, before commencing chemo–radiation therapy for a recently diagnosed malignant brain tumour. Two weeks prior, she had presented with seizures and undergone emergency craniotomy and tumour resection. Taking into consideration of the tight time frame and her comorbidities, several measures were undertaken to minimise the potential increase in intracranial pressure that may lead to cerebral oedema during laparoscopy. Preoperatively, the anaesthetist administered 8 mg dexamethasone as prophylaxis. Intraoperatively, the degree of head-down tilt was minimised to 10, which was just adequate to displace bowel cranially for visualisation of pelvic structures. Finally, a shorter operative time was achieved by ensuring the most senior surgeon performed the operation, and the procedure itself was altered from the standard approach of ovarian harvesting to unilateral oophorectomy. The patient made a quick recovery and was discharged home day 1 postoperatively.

Background

Gynaecological laparoscopy requires appropriate positioning of the patient to enhance visualisation of the pelvic cavity. Conventional practice is to place patients in lithotomy and steep Trendelenburg position (head-down tilt with the patient supine). The former allows vaginal examination, dilatation and curettage as well as manipulation of the uterus to aid laparoscopy. The latter allows cranial shifting of abdominal viscera to attain a clear operative field in the pelvis.

Steep Trendelenburg position refers to a head-down tilt to 45 degrees while the patient is supine.¹ It is tolerated by most patients undergoing laparoscopy, and the risks associated are usually managed prophylactically. A modified Trendelenburg position of head-down tilt to 15 degrees was designed for patients who are unable to tolerate steep Trendelenburg position. Few case reports have reported on further risk reduction techniques in patients who may not tolerate the modified Trendelenburg position.

We report a case of laparoscopic gynaecological surgery in which excessive head-down tilt was contraindicated, due to increased risk of cerebral oedema. Collaboration between the anaesthetist, gynaecologist and nursing staff was essential in order to perform the surgery safely. This case demonstrates the importance of operational flexibility, technical diligence and teamwork in overcoming the challenges to laparoscopic surgical approach.

Case presentation

A gravida 0, para 0 woman in her early 20s was referred for fertility-preserving treatments before commencing on chemo–radiation therapy. Two weeks prior, she had presented to a tertiary hospital emergency department by ambulance after suffering an unprovoked seizure while asleep. Her partner witnessed symptoms resembling a tonic-clonic seizure lasting about 90 s and called the ambulance. MRI findings included a right frontal lesion causing ventricular compression, leading to increased intracranial pressure (ICP) and seizures. Emergency craniotomy was performed and the tumour was resected. Histopathology results returned with features confirming an aggressive malignant grade III astrocytoma.

Her multidisciplinary treating team made a plan for her to undergo chemo–radiation therapy with curative intention. However, given her childbearing age and wishes to preserve fertility, a referral was made to a fertility specialist. The gynaecologist who saw the patient offered several fertility-preservation options to her, including cryopreservation of the ova, creation and cryopreservation of embryos, ovarian tissue and or ovary. Given the tight timeframe that she had before commencing cancer treatment, as well as the potential risk of ovarian failure from chemo-toxic agents, a decision for ovarian cryopreservation was made. This approach removed the requirement for ovarian stimulation, which requires at least 2 weeks to complete, and offered the additional benefit of ovarian reimplantation supporting hormonal supplementation, in the event of development of premature ovarian insufficiency secondary to chemotherapy.

Preoperatively, surgical and anaesthetic difficulties were identified. Given the patient’s recent neurosurgical history, as well as her medical co-morbidities, the steep Trendelenburg position during laparoscopy heralded risks of raised ICP and cerebral oedema. After careful discussion, five strategies were adopted to reduce the likelihood of adverse effects (see figure 1): (1) prophylactic dexamethasone 8 mg was administered preoperatively to reduce cerebral oedema. A traditional neurosurgical anaesthetic consisting of a total intravenous technique with meticulous attention to normocapnia was used. (2) head-down tilt angle was to be minimised as much as possible, without compromising the visualisation of the pelvic organs for the operation to proceed. It was measured later with a mobile application to be 10 degrees. (3) Intraoperative frontal electroencephalography (EEG) monitoring was performed to detect any abnormal brain activities. (4) Operation time was shortened, by ensuring the most senior surgeon performed the procedure and operative technique was chosen to maximise outcome and minimise complications. (5) Insufflation pressure was reduced to the minimum required to maintain pneumoperitoneum as soon as operative ports were entered. In this case, unilateral oophorectomy was chosen to minimise blood loss and hence procedural time, instead of ovarian harvesting (which involves removing a small wedge of ovarian tissue, but carries a higher potential risk of bleeding and additional haemostatic procedures to manage this). The entire operation lasted approximately 40 min.

Figure 1.

Summary of strategies used to prevent raised intracranial pressure. EEG, electroencephalography.

Outcome and follow-up

The patient made a rapid recovery and was discharged home day 1 postoperatively. She commenced radiotherapy 1 week after laparoscopic oophorectomy and had no postoperative complications at her 6-week review. The patient informed us that fertility treatment did not delay her cancer treatment, and that her treating doctors worked her cancer treatment dates around the preservation of her fertility as she stressed that it was very important to her. Here, the patient’s wishes were accommodated with close cooperation between multiple specialties.

Discussion

Strategies to address the risk of raised ICP in this patient commenced from the techniques employed by the anaesthetist at induction, such as the administration of dexamethasone, the positioning of the patient herself and finally a modification of operative technique (see figure 2). Prophylactic dexamethasone is commonly given during neurosurgery, which is not a well-documented method of preventing raised ICP when steep Trendelenburg position is adopted.^{2 3} In a comment to Kalmar et al, Dr George A discussed anecdotal evidence of a reduction in the number of patients with raised ICP, when dexamethasone was administered to prevent postoperative nausea and vomiting.⁴ No studies thus far have demonstrated the efficacy of preoperative dexamethasone in preventing raised ICP due to steep Trendelenburg. In this case report, the patient was given prophylactic dexamethasone based on the anaesthetist’s professional experience as well as recommendations from his colleagues. Intraoperative frontal EEG monitoring would have prompted immediate cessation of Trendelenburg position if any abnormalities were present, thus ensuring the patient’s safety.

Figure 2.

Strategies used to prevent raised intracranial pressure and their supporting evidence.

Increased intracranial and intraocular pressures are well-documented adverse effects of steep Trendelenburg position in laparoscopic pelvic surgeries.^5–10 While the modified Trendelenburg position with less head-down tilt has been suggested as an alternative, Raz et al proposed a modified Z Trendelenburg position with the shoulder and head in the supine position.¹¹ This has been shown to have a positive impact on patient safety. Therefore, based on current evidence, it is reasonable to suggest that minimising the degree of head-down tilt while still achieving an adequate view of the pelvis should be the aim of all laparoscopic pelvic surgeries. Careful consideration must be taken not to compromise the available pelvic space for the surgeon to work on and needing extra assistance with holding viscera away from the pelvis.

The authors believe that several other strategies may be used in future operations with similar challenges to optimise visualisation of the pelvic space. Fat retraction has been described by Sivagnanam et al by suturing intra-abdominal fat (omentum) laparoscopically and removing the suture via port site, to allow for guided retraction of structures attached to it.¹² The senior author of that study, Rhodes, has practised this technique for 15 years under direct visualisation to prevent damage to viscera and has not reported any adverse events. A similar technique can be employed in gynaecological laparoscopy when Trendelenburg position is undesirable, by suturing bowel epiploica onto the anterior abdominal wall to attain adequate visualisation. Alternatively, an organ retraction sponge such as Endoractor can be used to maintain the retraction of bowel when returned from Trendelenburg to horizontal position.^{13 14} In a study by Matsuoka et al, bowel remained retracted using Endoractor in all 24 patients undergoing gynaecologic laparoscopic surgery when the position changed from Trendelenburg to horizontal.¹⁵ The aforementioned techniques should take into account the patient’s habitus as well as other complicating surgical factors such as previous intra-abdominal surgery in order to individualise the surgical plan. Fat retraction is of value if pelvic visualisation is suboptimal with minimal tolerable head-down tilt, which did not occur in this case. Similarly, Endoractor was not required given the excellent views obtained. In an overweight patient, these techniques may have been of greater consideration. In this case report, the patient was young and otherwise healthy with no previous history of abdominal surgery. Therefore, the laparoscopic gynaecological surgeon was confident in gaining an optimal view of the pelvic cavity without needing to use the two techniques mentioned. This was with the goal of shortening the duration of the operation and anaesthesia, which in turn reduces the risk of raised ICP.

Apart from maximising visualisation without head-down tilt, we can also prevent other factors from causing raised ICP. Studies have shown that an increase in intraabdominal pressure from gas insufflation may result in elevated ICP.¹⁶ In patients where elevation of ICP needs to be avoided, gas insufflation of abdomen should be carried out at the lowest gas pressure possible during laparoscopic surgery. Novel devices such as Air Seal have been efficient in establishing pneumoperitoneum using lower pressure gas insufflation.¹⁷ This is an area where further studies are required, to establish more effective ways of minimising intra-abdominal pressure during laparoscopic surgery. Another predictor of raised ICP is the intraoperative duration, with studies showing lower risk of elevated ICP with shorter duration in Trendelenburg position.^{7 18} In this case, the time spent in Trendelenburg position was minimised by senior surgical staffing, modification of operative technique and good communication between the gynaecologists, anaesthetists and nursing staff in the preoperative briefing. Laparotomy was discussed with patient prior to surgery as a safety net measure, in the event that ICP rose and surgery needed to be completed within the shortest duration possible, without compromising cerebral perfusion. The risks associated with laparotomy were explained to the patient, including greater risk of bleeding, prolonged wound healing and recovery time. Laparotomy may also delay patient’s suitability for chemotherapy, therefore, delaying the treatment cycle. These possibilities were raised to enable informed decision-making.

To our knowledge, this is the first case report demonstrating the feasibility of minimum head-down tilt during laparoscopic surgery, when steep or modified Trendelenburg position are not tolerated. This report provides evidence for future operations where the patient is unlikely to tolerate excessive or prolonged head-down tilt. Perioperative discussion with the patient, anaesthetist and surgeon is essential in formulating preventative strategies. Future observational studies are still necessary to validate the strategies that have been suggested within this report.

Learning points.

• This is a case of laparoscopic surgery in patients who are unable to tolerate Trendelenburg position due to the risk of cerebral oedema and elevated intracranial pressure.

• Prophylactic administration of dexamethasone, minimisation of the degree of head-down tilt, continuous electroencephalography monitoring and consideration to shortest operation approach may be effective strategies.

• One must consider an open approach if even minimal Trendelenburg is poorly tolerated.