Transient cortical blindness following bypass graft angiography. A case report

Incidence and Risk Factors for Postoperative Visual Loss after Cardiac Surgical Procedures: A Systematic Review

ABSTRACT

Postoperative visual loss (POVL) is an infrequent yet consequential complication that can follow cardiac surgical interventions. This systematic review aims to provide a comprehensive analysis of the incidence of POVL after cardiac surgery and to delineate the associated risk factors. A comprehensive search was conducted in major medical databases for relevant studies published up to September 2022. Eligible studies reporting on the incidence of POVL and identifying risk factors in patients undergoing cardiac surgery were included. Data extraction was performed independently by two reviewers. The pooled incidence rates and the identified risk factors were synthesized qualitatively. POVL after cardiac surgery has an overall incidence of 0.015%, that is, 15 cases per 100,000 cardiac surgical procedures. Risk factors for POVL include patient characteristics (advanced age, diabetes, hypertension, and preexisting ocular conditions), procedural factors (prolonged surgery duration, cardiopulmonary bypass time, and aortic cross-clamping), anesthetic considerations (hypotension, blood pressure fluctuations, and specific techniques), and postoperative complications (stroke, hypotension, and systemic hypoperfusion). Ischemic optic neuropathy (ION) is an uncommon complication, associated with factors like prolonged cardiopulmonary bypass, low hematocrit levels, excessive body weight gain, specific medications, hypothermia, anemia, raised intraocular pressure, and micro-embolization. Diabetic patients with severe postoperative anemia are at increased risk for anterior ischemic optic neuropathy (AION). Posterior ischemic optic neuropathy (PION) can occur with factors like hypertension, postoperative edema, prolonged mechanical ventilation, micro-embolization, inflammation, hemodilution, and hypothermia.While the overall incidence of POVL postcardiac surgery remains modest, its potential impact is substantial, necessitating meticulous consideration of modifiable risk factors. Notably, prolonged surgical duration, intraoperative hypotension, anemia, and reduced hematocrit levels remain salient contributors. Vigilance is indispensable to promptly detect this infrequent yet visually debilitating phenomenon in the context of postcardiac surgical care.

Case Report and Literature Review on Low-Osmolar, Non-Ionic Iodine-Based Contrast-Induced Encephalopathy

Contrast-induced encephalopathy (CIE) is a rare complication following percutaneous carotid and coronary interventions, and important diagnostic radiological signs include brain edema and cortical enhancement. In this report, we detail a case of probable CIE in an 84-year-old woman following a normal diagnostic coronary angiography (CAG) that involved 20 mL of the low-osmolar, non-ionic monomeric, iodine-based contrast agent iopromide (Ultravist 370). The patient was unconscious and presented with hemiparesis, hemianopia, recurrent seizures, and cardiac and respiratory arrest within minutes to hours following the procedure. Non-contrast computed tomography (CT) of the head showed increased subarachnoid density, cortical enhancement, and brain edema in the right hemisphere. Three days of rehydration, reduction in cranial pressure, and treatment with an anticonvulsant and dexamethasone resulted in a gradual recovery with no neurological deficits. This case highlights that severe neurotoxic symptoms may occur in response to low doses of low-osmolar, non-ionic, monomeric contrast agents. This finding is of importance to interventional cardiologists for diagnostic considerations and development of treatment plans.

Rare Cases of Contrast-Induced Encephalopathies

Cortical blindness (CB) due to contrast-induced encephalopathy is a rare complication in endovascular procedure. Although exact mechanism is not known, disruption of blood–brain barrier (BBB) by contrast agent is supposed to be caused. We report two cases of contrast-induced encephalopathies after coil embolization of unruptured aneurysm. A 68-year-old woman with unruptured basilar artery aneurysm was treated with endovascular stent-assisted coil embolization. The procedure was successfully accomplished within 172 min using about 160 ml of contrast medium (iopamidol). However, she manifested with CB 3 h after the procedure and seizure on the next day. Immediate computed tomography revealed the cortical enhancement in both occipital lobes. Diffusion-weighted imaging–magnetic resonance imaging and fluid-attenuated inversion recovery sequence 1 day after the procedure revealed edema in both occipital lobes with no findings of ischemia or hyperperfusion. Electroencephalography showed sharp and slow waves in both occipital lobes. She required endotracheal intubation on day 2 to maintain airways and breathing. Her sensorium improved 4 days after the procedure with administration of steroid and anticonvulsant. She was extubated on day 4 after the procedure. She was discharged with persisting CB as a sequel.

Irreversible fatal contrast-induced encephalopathy: a case report

Background

Contrast-induced encephalopathy (CIE) is a well-known complication of iodinated contrast agents during angiography and vascular interventions. It can manifest as hemiparesis, cortical blindness, speech changes, Parkinsonism, confusion, seizure, and coma. Most of the reported CIE cases have been transient and reversible. Irreversible fatal CIE cases have been rarely reported. All the fatal CIE cases reported involved the use of ionic high osmolar contrast agents. Here, we document a heretofore unreported fatal CIE after digital subtraction angiography (DSA) using iopamidol, which is a type of non-ionic monomer low osmolar contrast agent.

Case presentation

A 71-year-old woman was admitted to our Department of Neurology for tinnitus in the head. The cerebral magnetic resonance angiography (MRA) detected atherosclerotic cerebral arteries and bilateral stenosis of the middle cerebral arteries. The patient underwent DSA for further diagnostic work-up. The total amount of iopamidol used during the procedure was 110 ml. The patient experienced headache during the procedure, followed by dizziness with nausea and vomiting. Despite treatment with anti-oedema medications, her clinical status was gradually deteriorating and ended up with deep coma due to irreversible cerebral oedema which was confirmed by cerebral computed tomography (CT). Finally, the patient died 56 days after the procedure due to irreversible fatal cerebral oedema.

Conclusions

This report documents that iopamidol-induced encephalopathy may not always have a benign outcome and can result in irreversible fatal cerebral oedema.

Contrast-induced neurotoxicity after coronary angiography

BACKGROUND

Contrast-induced neurotoxicity (CIN) is a very rare complication of coronary angiography. Clinical presentations include encephalopathy, seizures, cortical blindness, and focal neurological deficits. An inherent difficulty in understanding the natural history of the condition as well as its risk factors and prognosis is the rarity of its occurrence. To date, there are only case reports published on this complication.

PATIENTS AND METHODS

This was a retrospective analysis of 9 patients with CIN (8 men, 1 woman; mean age, 64.6 ± 7.8 years; range, 47-72 years) and coronary artery disease who were administered iopromide contrast agent.

RESULTS

In the last 3 years, we diagnosed 9 patients with CIN. Of these, 8 patients (89 %) had hypertension. The clinical presentations of the patients were different on admission: 6 patients had acute coronary syndrome and 3 patients had stable angina pectoris. One patient had history of previous contrast agent exposure. All patients underwent coronary angiography with a low-osmolar nonionic monomer contrast agent (iopromide; Ultravist®-300, Bayer Healthcare). The mean volume of contrast injected was 177 ± 58 ml. The mean time between contrast agent administration and clinical symptoms was 100 ± 71 min (range, 30-240 min). While in 5 of the patients (56 %) the clinical sign of CIN was confusion, 2 had ophthalmoplegia, 1 had cerebellar dysfunction, and 1 had monoplegia. In 8 of 9 patients (89 %), neurological symptoms resolved after giving supportive medication and hydration. Only 1 female patient, who had bilateral ophthalmoplegia, did not recover. Neurological recovery occurred at a mean time of 14.2 ± 6.7 h (range, 8-30 h).

CONCLUSION

CIN is a very rare condition. Advanced age, male gender, and hypertension are the greatest risk factors for CIN. Although the prognosis of CIN is benign, it can potentially cause permanent neurological deficits or death. We found that patients with ophthalmic involvement had a higher propensity for persistent deficit. On the basis of the current data, we propose 170 ml as the maximal recommended dose for coronary procedures.

An atypical case of contrast-induced encephalopathy after carotid artery stenting

Neurotoxicity caused by contrast agents is a rare and less known complication of percutaneous carotid and coronary interventions. Radiological signs, such as cortical enhancement and brain edema, are of utmost importance in diagnosis. A 70-year-old female patient underwent left carotid artery stenting to treat a post-traumatic asymptomatic carotid dissection. Three hours after intervention, a mild aphasia developed with no brain alteration on diffusion-weighted magnetic resonance imaging (DW-MRI). Twelve hours after intervention, symptoms worsened but a new DW-MRI scan showed no pathological findings. Since a contrast-induced encephalopathy was diagnosed, fluid administration was raised to 2 mL/kg/h and the neurological status progressively improved. In the following three days, neurological deficit slowly regressed. Two weeks after intervention, aphasia had disappeared and a further cerebral DW-MRI scan detected no brain alteration. Typical radiological signs are described in association to contrast encephalopathy. Nevertheless, vascular interventional physicians should be well aware of this condition also when those signs are lacking.

Persistent neurological deficit from iodinated contrast encephalopathy following intracranial aneurysm coiling. A case report and review of the literature

Neurotoxicity from iodinated contrast agents is a known but rare complication of angiography and neurovascular intervention. Neurotoxicity results from contrast penetrating the blood-brain barrier with resultant cerebral oedema and altered neuronal excitability. Clinical effects include encephalopathy, seizures, cortical blindness and focal neurological deficits. Contrast induced encephalopathy is extensively reported as a transient and reversible phenomenon. We describe a patient with a persistent motor deficit due to an encephalopathy from iodinated contrast media administered during cerebral aneurysm coiling. This observation and a review of the literature highlights that contrast-induced encephalopathy may not always have a benign outcome and can cause permanent deficits. This potential harmful effect should be recognised by the angiographer and the interventionalist.

Transient cortical blindness after heart surgery in a child patient -A case report-

Visual loss occurring after pediatric cardiac surgery employing cardiopulmonary bypass (CPB) is relatively rare but the risk is substantial. Compromised cerebral perfusion due to a CPB related micro-embolization and inflammatory vascular changes as well as reduced oxygen carrying capacity in hemodilution and hypothermia during CPB might be major contributing factors to the development of postoperative visual loss after cardiac surgery with CPB. A case of immediate but transient postoperative visual loss was encountered in a 21-month-old male who underwent tricuspid valve surgery. Despite routine intraoperative measures to maintain an adequate perfusion pressure throughout the procedure, postoperative computed tomography revealed a subacute infarct in his occipital lobe. Recovery began on postoperative day 28, and the patient's vision was restored by 31 days.

Transient cortical blindness after coronary angiography

Transient cortical blindness is rarely encountered after angiography of native coronary arteries or bypass grafts. This paper reports a case of transient cortical blindness that occurred 72 h after coronary angiography in a 56-year old patient. This was the patient's fourth exposure to contrast medium. Neurological examination demonstrated cortical blindness and the absence of any focal neurological deficit. A non-contrast-enhanced computed tomographic scan of the brain revealed bilateral contrast enhancement in the occipital lobes and no evidence of cerebral haemorrhage, and magnetic resonance imaging of the brain showed no pathology. Sight returned spontaneously within 4 days and his vision gradually improved. A search of the current literature for reported cases of transient cortical blindness suggested that this is a rarely encountered complication of coronary angiography.

An unusual but dramatic complication of coronary angiography: transient cortical blindness

A 52-year-old woman developed transient cortical blindness after coronary angiography. Its occurrence after coronary angiography is far less common. A possible mechanism of this complication may be contrast penetration of the blood-brain barrier with direct neurotoxicity to the occipital cortex. Patient outcome is excellent, with complete recovery expected within 24-48 h.

Cortical blindness during coil embolization of an unruptured intracranial aneurysm--case report

A 62-year-old woman suffered transient cortical blindness during coil embolization for a saccular aneurysm in the posterior circulation, with cerebral angiography using non-ionic contrast material. Just before completion of the procedure, the patient showed abrupt onset of restlessness and blindness. At this point 150 ml of contrast material had been injected into the left vertebral artery. Immediate computed tomography showed persistence of contrast medium in the bilateral occipital lobes and part of the left frontal lobe. Repeat angiography showed no evidence of embolism. Single photon emission computed tomography obtained the next day showed decreased perfusion in the bilateral occipital lobes. Magnetic resonance imaging on the third day showed multiple lesions in the bilateral occipital lobes. Her vision was restored gradually. Transient cortical blindness may be associated with osmotic disruption of the blood-brain barrier in the bilateral occipital lobes. Endovascular neurosurgeons must be aware of this rare complication.

Safety of coronary arteriography in clinically stable patients following coronary bypass surgery. Post CABG Clinical Trial Investigators

The frequent use of diagnostic coronary arteriography and its importance in evaluating results of intervention in clinical trials emphasize the necessity of continued assessment of procedural risk. Several studies have described such risks, but they have often included a diverse group of patients with varying levels of clinical stability. Furthermore, this risk has not been well established in a population of patients with saphenous vein bypass grafts. There is need to define the risk of coronary arteriography in a group of patients who are both clinically similar and stable, and to evaluate the influence of improved technology and increased operator experience on the risk of the procedure. The National Heart, Lung, and Blood Institute-funded Post Coronary Artery Bypass Graft Trial offered the opportunity to evaluate the risk of elective diagnostic coronary arteriography in clinically stable patients studied at two points in time: pre-enrollment and 4-5 years after study entry. In this group of 2,635 angiograms from clinically stable patients over 5 years there were no deaths and the risk of myocardial infarction was 0.08%, while 0.7% had clinically important complications. Non-elective, urgent studies (311 angiograms) on unstable patients were more likely to include angioplasty and were associated with a risk of death of 0.6% and myocardial infarction of 1.3%. Complications did not vary with age or gender. Vascular trauma was more likely to occur using the brachial than the femoral artery entry sites. These results indicate that elective angiography on stable patients can be accomplished with a very low risk of mortality (0% in this study) or serious cardiovascular complication. This supports the safety and usefulness of angiography for clinical intervention trials.