Perioperative visual loss and consent for adult spine surgery: a national survey of the practice amongst spine surgeons and anaesthetists†

BACKGROUND

Perioperative Visual Loss (POVL) is a devastating complication for patients undergoing spine surgery. Consent process for POVL amongst spine surgeons and anaesthetist remains variable. The aim of this study is to evaluate their practice and views about it.

METHODS

Two similar questionnaires were distributed to members of the Society of British Neurological Surgeons (SBNS), British Association of Spine Surgeons (BASS), and Neuroanaesthsia and Critical Care Society (NACCS).

RESULTS

A total of 271 responses were received (SBNS/BASS n = 149, NACCS n = 122). Fewer surgeons considered POVL as a material risk for patients compared to the anaesthetists (57.7 versus 79.7%). Outpatient/pre-assessment clinics were considered as the optimal setting for discussing POVL by the majority of the clinicians (81.2 and 93.4%). POVL should be discussed by both specialists according to 75% of the anaesthetists. Estimated incidence of POVL was considered to be higher by the anaesthetists (0.03-0.2% by 63% of the anaesthetist versus 0.0001-0.004% by 57% of the surgeons). Twenty-three surgeons and 10 anaesthetists had a patient who suffered from POVL, which led to a change of practice in most of them. This questionnaire will lead to a change in practice/consent to 18.1% of the surgeons and 23.5% of the anaesthetists.

CONCLUSIONS

Most of the surgeons and anaesthetist feel that POVL is a material risk that ideally needs to be firstly discussed before the day of surgery, by both specialties. However, a significant number of clinicians have an opposite view. A national guidance from respective societies should encourage POVL to be discussed routinely.

The ideal patient positioning in spine surgery: a preventive strategy

Patient positioning on the surgical table is a critical step in every spine surgery. The most common surgical positions in spine surgery are supine, prone and lateral decubitus. There are countless lesions that can occur during spine surgery due to patient mispositioning. Ulnar nerve and brachial plexus injuries are the most common nerve lesions seen in malpositioned patients. Devastating complications due to increased intraocular pressure or excessive abdominal pressure can also occur in prone decubitus and are real concerns that the surgical team must be aware of. All members of the surgical team (including surgeons, anesthesiologists and nurses) should know how to correctly position the patient, identify possible positioning errors and know how to avoid them in order to prevent postoperative morbidity. This work pretends to do a review of the most common positions during spine surgery, alert to errors that can happen during the procedure and how to avoid them.

Cortical Blindness after Cervical Spine Surgery in Supine Position - A Rare Case Report and Review of the Literature

We report the first case of perioperative visual loss due to cortical blindness after supine cervical spine surgery. A 46-year-old female presented with severe right-sided brachialgia of 1½ years' duration. Her magnetic resonance imaging (MRI) (cervical spine) showed severe right foraminal stenosis at C5–6. She underwent C5–6 anterior cervical discectomy and fusion. Nine hours after surgery, during a routine postoperative round, the patient complained of complete bilateral visual loss. The fundus examination and pupillary light reflex were normal. MRI of the brain showed the posterior cerebral artery infarct with hypoplasia of the left vertebral artery. She was transferred to the neurointensive care unit where antiplatelet treatment was started along with heparin. Her vision slowly began to improve, and at the end of 1 year, she had a reasonable visual acuity in both eyes. It is now standard practice in our institution to check patients' vision immediately after surgery.

Checking the integrity of eyes in prone position: A novel application of video laryngoscopes

Perioperative visual loss is a rare but severe complication after surgery in prone position. One of several mechanisms is direct ophthalmic compression. This can be avoided through optimal positioning and padding of the head, but position and integrity of the eyes need to be checked at regular intervals. We describe the use of a conventional video laryngoscope during vascular surgery in prone position as a simple solution for intermittent monitoring of external integrity of the eyes and size of the pupils. This requires no additional material and allows documentation of the findings. Our method might reduce complications and improve patient outcome.

Intraocular pressure during neurosurgical procedures in context of head position and loss of cerebrospinal fluid

OBJECTIVE

Perioperative visual loss (POVL) is a rare but serious complication in surgical disciplines, especially in spine surgery. The exact pathophysiology of POVL remains unclear, but elevated intraocular pressure (IOP) is known to be part of it. As POVL is rarely described in patients undergoing intracranial or intradural surgery, the aim of this study was to investigate the course of IOP during neurosurgical procedures with opening of the dura mater and loss of CSF.

METHODS

In this prospective, controlled trial, 64 patients fell into one of 4 groups of 16 patients each. Group A included patients undergoing spine surgery in the prone position, group B patients had intracranial procedures in the prone position, and group C patients were treated for intracranial pathologies in a modified lateral position with the head rotated. In groups A-C, the dura was opened during surgery. Group D patients underwent spine surgeries in the prone position with an intact dura. IOP was measured continuously pre-, peri-, and postoperatively.

RESULTS

In all groups, IOP decreased after induction of anesthesia and increased time dependently after final positioning for the operation. The maximum IOP in group A prior to opening of the dura was 28.6 ± 6.2 mm Hg and decreased to 23.44 ± 4.9 mm Hg directly after dura opening (p < 0.0007). This effect lasted for 30 minutes (23.5 ± 5.6 mm Hg, p = 0.0028); after 60 minutes IOP slowly increased again (24.5 ± 6.3 mm Hg, p = 0.15). In group B, the last measured IOP before CSF loss was 28.1 ± 5.0 mm Hg and decreased to 23.5 ± 6.1 mm Hg (p = 0.0039) after dura opening. A significant IOP decrease in group B lasted at 30 minutes (23.6 ± 6.0 mm Hg, p = 0.0039) and 60 minutes (23.7 ± 6.0 mm Hg, p = 0.0189). In group C, only the lower eye showed a decrease in IOP up to 60 minutes after loss of CSF (opening of dura, p = 0.0007; 30 minutes, p = 0.0477; 60 minutes, p = 0.0243). In group D (control group), IOP remained stable throughout the operation after the patient was prone.

CONCLUSIONS

This study is the first to demonstrate that opening of the dura with loss of CSF during neurosurgical procedures results in a decrease in IOP. This might explain why POVL predominantly occurs in spinal but rarely in intracranial procedures, offers new insight to the pathophysiology of POVL, and provides the basis for further research and treatment of POVL.German Clinical Trials Register (DRKS) no.: DRKS00007590 (drks.de).

Ischemic optic neuropathy in robotic-assisted gynaecologic surgery: A case report

The study was aimed to present a rare case of who developed non arteritic anterior ischemic optic neuropathy (NAION) following robotic-assisted gynaecologic surgery. A 58-year-old female patient presented with vision loss in right eye after non-complicated robotic-assisted total hysterectomy and bilateral salpingo-oopherectomy. We observed on fundoscopy optic disc edema and splinter hemorrhages at the optic disc edges. Fluorescein angiography showed hypofluorescence of the optic disc in the early phases due to filling delay followed by hyperfluorescence with leakage from disc capillaries in the late phases of the angiogram. From these findings, we diagnosed NAION in the right eye. When NAION was diagnosed, the patient received intravenous methylprednisolone. Topical brimonidin and coenzyme-Q were given. On 1-month follow-up, recovery of visual loss was observed. Here, we present a case of NAION that is an uncommon cause of perioperative visual loss after robotic-assisted gyneacologic surgery.

Unilateral blindness after orthognathic surgery: hypotensive anaesthesia is not the primary cause

Perioperative vision loss in non-ocular surgery represents a rare but devastating complication and multiple causes have been proposed. Any portion of the visual system may be involved and several authors have tried to relate that complication with deliberate hypotension anaesthetic technique, used to control intraoperative bleeding. We report a patient operated for orthognathism who suffered unilateral blindness. After review of similar cases, we can state that the transmission of forces generated during Le fort I osteotomy is related to the complication. This osteotomy technique is regularly performed in our hospital using a curved osteotome to achieve the pterygomaxillary disjunction and the adverse transmission of forces via the sphenoid bone is the main reason for indirect damage to the optic nerve and its vascular structures causing the neuropathy and blindness. Hypotensive anaesthesia may certainly lead to transient ischaemia but only in specific cases because of decreased ocular perfusion pressured.

Ocular Complications in Laparoscopic Surgery: Review of Existing Literature and Possible Prevention and Treatment

During laparoscopic surgery, ocular complications are possible, sometimes leading to devastating visual losses, hardly susceptible to recovery, although rare. Principal ocular adverse events are represented by corneal abrasions and the perioperative visual loss (POVL). POVL onset is related to intraocular pressure elevations (particularly after patient positioning in Trendelenburg or prone decubitus, depending on the surgical procedure), anesthesiologic factors and patients' characteristics. In the light of evidence from the existing literature, the authors suggest surgical and anesthesiologic measures to prevent and manage ocular complications in laparoscopic surgery. Apart from general recommendations, this article indicates practical guidelines specific for robot-assisted laparoscopic interventions and spinal surgery, as well as laparoscopic colorectal resection, radical prostatectomy, and gynecologic surgery. In conclusion, in order to better manage these complications, it is advisable to develop an interdisciplinary collaboration between surgeons, anesthesiologists, and ophthalmologists, on a procedural and medico-legal level, with the intent of mutual training.