Absceso cerebral múltiple del lóbulo temporal derecho, reporte de un caso / Multiple brain abscess of the right temporary lobe, report of a case

RESUMEN El absceso cerebral es un proceso infeccioso focal del parénquima cerebral. Se inicia con un área localizada de cerebritis y progresa a una colección de pus rodeada por una cápsula bien vascularizada. La mortalidad oscila entre 5 a 15 % de los casos, excepto en la ruptura intraventricular del absceso cerebral, situación en que la mortalidad oscila entre 38 a 84 %, con tasas altas de discapacidad en los sobrevivientes. Se presentó un caso de 47 años, con sintomatología neurológica infecciosa, además de signos neurológicos que demuestran el trastorno funcional del lóbulo temporal no dominante. Se realizaron varios exámenes complementarios y se diagnosticó dos abscesos cerebrales temporales derechos. Fue intervenido neuroquirúrgicamente, su evolución fue satisfactoria con regresión de casi la totalidad de los síntomas prequirúrgicos presentados (AU).

ABSTRACT Brain abscess is a focal infectious process of the brain parenchyma. It begins with a located area of cerebritis and progresses to a pus collection surrounded by a well-vasculirized capsule. Mortality oscillates from 5 % to 15% of the cases, except in the intraventricular rupture of the brain abscess, situation in which mortality oscillates from 38 % to 84 %, with high rates of disability in survivors. The case presented is the case of a patient aged 47 years, with infectious neurologic symptoms besides neurologic signs showing the functional disorder of the non-dominant temporal lobe. Several complementary tests were carried out and two right temporal brain abscesses were diagnosed. The patient underwent a neurosurgery; his evolution was satisfactory with the almost total regression of the symptoms before surgery (AU).

Localización preoperatoria de la trepanación inicial en el abordaje retrosigmoideo. Revisión de literatura y aplicación quirúrgica / Preoperative location of the initial trepanation in the retrosigmoid approach. Literature review and surgical application

Objetivo: Evaluar una técnica eficaz y reproducible que permita determinar el sitio de la trepanación inicial en el abordaje retrosigmoideo. Materiales y métodos: Se empleó una muestra de 22 pacientes a fin de analizar la relación de la transición transverso ­ sigmoidea (TTS) con el asterion y la ranura digástrica. Todos los casos contaban con TC de cortes finos (1 mm de espesor). Se subdividieron los pacientes en dos grupos. Grupo 1: pacientes con patologías variables, sin alteraciones estructurales en la fosa posterior. Grupo 2: pacientes en los que se realizó un abordaje retrosigmoideo con planificación prequirúrgica del sitio de trepanación inicial. Discusión: Las referencias óseas (asterion y punto digástrico) pudieron identificarse en la totalidad de las TC 3D analizadas. Se analizaron las distancias empleando un sistema de coordenadas. La TTS se registró en el 78% de los casos anterior e inferior al asterion. En ningún caso se encontró la TTS superior al asterion, la ubicación en sentido inferior varió entre 0 mm y 25,5 mm (media 12,5 mm). En el plano anteroposterior, se registró una distancia entre -6,41 mm y 14,5 mm (media 4,09 mm), demostrando una gran variabilidad individual, comparable con lo descripto en la literatura. En el grupo 2, pudo predecirse de manera precisa la localización de la TTS, exponiendo la misma con la trepanación inicial. Conclusión: Se describe un método sencillo, eficaz, de libre acceso, que permite la ubicación del keyhole en el abordaje retrosigmoideo

Objective: To assess an effective and reproducible technique that allows determining the emplacement of the initial burr-hole in the retrosigmoid approach. Materials and methods: A sample of 22 patients was used to analyze the relation among the transverse - sigmoid transition (TTS), the asterion and the digastric groove. All cases had a thin-slice, 1-mm-thick Computed Tomography (CT). Patients were subdivided into two groups. Group 1: patients with variable pathologies, without structural modification of posterior fossa anatomy. Group 2: patients in which a retrosigmoid approach was performed with preoperative surgical planning of the initial burr-hole. Discussion: Bone references (asterion and digastric point) could be identified in the totality of the analyzed 3D CT. The distances were measured using a coordinate system. TTS was recorded in 78% of the cases inferior and anterior to the asterion. In no case the TTS was found superior to the asterion. It was 0 mm to 25.5 mm (mean 12.5 mm) inferior; and a distance between -6.41mm to 14.5mm (mean 4.09mm) in the anteroposterior plane was recorded, demonstrating a large individual variability. In group 2, the location of the TTS could be accurately predicted, exposing it with the initial burr-hole. Conclusion: A simple, effective and access free method is described, which allows the emplacement of the keyhole in the retrosigmoid approach

History and Evolution of Epilepsy Surgery

The surgical treatment for epilepsy has a worldwide historical relevance for centuries. There are archaeological reports that date it back to ancient Egypt; however, the year 1886 is considered a landmark in the surgical treatment for epilepsy in theModern Age, when the first surgery for the treatment of focal epileptic events was performed successfully. Since then, innumerable related articles have been published evoluonarily. Over the last centuries, new techniques and technologies provided better understanding, diagnosis and management for this disease. Thus, historical and evolutionary knowledge becomes important to let us better understand the current position of the surgery for epilepsy treatment and control.

Abducens Nerve Palsy as Initial Manifestation of Chronic Subdural Hematoma: Case Report

Chronic subdural hematoma (CSDH) is a form of progressive intracranial hemorrhage, typically associated with cases of trauma. The manifestation of this comorbidity with abducens palsy is a rare finding. The present work aims to describe the case of an adult patient with abducens nerve palsy as a manifestation of CSDH. Chronic subdural hematoma is most commonly found in elderly patients, with systemic hypertension as amanifestation. The relation with the sixth cranial nerve is unusual and draws attention to the case reported. In addition, the prognosis is positive, since trepanation and drainage surgery was performed, as it is recommended in the literature.

How to Treat Chronic Subdural Hematoma? Past and Now

Treatment of chronic subdural hematoma (CSDH) is relatively straightforward, however, there is still some debate regarding the best strategy for treatment. The most practical recommendations of up to date were identified by a review of literature. The author reviewed the literature on CSDH management from the past to now to identify the best methods. Till 1970s, craniotomy was the most commonly used method. Burr hole (BH) became the most preferred method from 1980s. In 1977, twist drill (TD) craniostomy was introduced. Closed system drainage after a BH or a TD became the most frequently used surgical method. Although nonsurgical treatment is often successful, trephination has more advantages, such as rapid resolution of the symptoms and short period of hospitalization. Nonsurgical treatment is possible in asymptomatic patients with a small CSDH. For the symptomatic patients with CSDH, trephination is the treatment of choice, either by BH or TD. In gray zone between surgery and medical treatment, shared decision making can be an ideal approach. For the recurrent CSDHs, repeated trephination is still effective for patients with a low risk of recurrence. If the risk of recurrence is high, additional management would be helpful. For the refractory CSDHs, it is necessary to obliterate the subdural space.

Delayed Extensive White Matter Injury Caused by a Subdural Hemorrhage and Role of Corticospinal Tract Integrity

A subdural hemorrhage (SDH) is a common disorder with usually good prognosis. Most SDHs resolve with or without with minimal sequelae. We present a case report of a patient with SDH, who had delayed extensive white matter injury with disruptions of corticospinal tracts (CSTs) by diffusion tensor imaging (DTI) and showed abysmal prognosis, despite long-term rehabilitation. A 62-year-old man with an SDH underwent burr hole trephination for hematoma removal. Within 7 days, the hemorrhage diminished. At 12 weeks after the onset, the patient's weakness did not improve, and a follow-up magnetic resonance imaging revealed extensive leukomalacia, especially in the white matter. The DTI for CST revealed severe injury of CST integrity. He did not re-gain muscle strength and functional independence, despite 3 months of inpatient rehabilitation. This case describes SDH with delayed extensive white matter injury and exceptional poor prognosis and urges caution in that the SDH may induce very variable functional recovery. Besides, DTI for CST would be useful in predicting the long-term functional prognosis in extensive white matter injury.

Epidural Abscess Caused by Eikenella corrodens in a Previously Healthy Child

Eikenella corrodens rarely causes invasive head and neck infections in immunocompetent children. We report a case of epidural abscess caused by E. corrodens in a previously healthy 13-year-old boy who presented with fever, headache, and vomiting. On physical examination upon admission, there was no neck stiffness, but discharge from the right ear was observed. Brain magnetic resonance imaging (MRI) revealed approximately 4.5-cm-sized epidural empyema on the right temporal lobe as well as bilateral ethmoid and sphenoid sinusitis, right mastoiditis, and right otitis media. During treatment with vancomycin and cefotaxime, purulent ear discharge aggravated, and on follow-up brain MRI, the empyema size increased to 5.6×3.4 cm with interval development of an abscess at the right sphenoid sinus. Burr hole trephination was performed, and foul-smelling pus was aspirated from the epidural abscess near the right temporal lobe. Pus culture yielded E. corrodens. Endoscopic sphenoidotomy was also performed with massive pus drainage, and the same organism was grown. The patient was treated with intravenous cefotaxime for 3 weeks and recovered well with no other complications. Therefore, E. corrodens can cause serious complications in children with untreated sinusitis.

Delayed Operation of Acute Subdural Hematoma in Subacute Stage by Trephine Drainage using Urokinase / 대한신경손상학회지

OBJECTIVE: The principle operation of acute subdural hematoma (ASDH) is a craniotomy with hematoma removal, but a trephination with hematoma evacuation may be another method in selected cases. Trephine drainage was performed for ASDH patients in subacute stage using urokinase (UK) instillation, and its results were evaluated. METHODS: Between January 2016 and December 2018, the trephine evacuation using UK was performed in 9 patients. The interval between injury and operation was from 1 to 2 weeks. We underwent a burr hole trephination with drainage initially, and waited until the flow of liquefied hematoma stopped, then instilled UK for the purpose of clot liquefaction. RESULTS: The mean age of patients was 71.6 years (range, 38–90 years). The cause of ASDH was trauma in 8 cases, and supposed a complication of anticoagulant medication in 1 case. Four out of 8 patients took antiplatelet medications and one of them was a chronic alcoholism. The range of the Glasgow Coma Scale score before surgery was from 13 to 15. Most of patients, main symptom was headache at admission. The Glasgow Outcome Scale score was 5 in 8 cases and 3 in 1 case. CONCLUSION: It is thought to be a useful operation method in selected patients with ASDH that the subdural drainage in subacute stage with UK instillation. This method might be another useful option for the patients with good mental state regardless of age and the patients with a risk of bleeding due to antithrombotic medications.

Burr Hole Drainage versus Small Craniotomy of Chronic Subdural Hematomas / 대한신경손상학회지

OBJECTIVE: Chronic subdural hematoma drainage is one of the most common procedures performed in neurosurgical practice. Not only burr hole drainage but also small craniotomy (diameter 3–5 cm) is frequently used neurosurgical treatment of chronic subdural hematomas. We assessed to compare the postoperative recurrence rates between burr hole drainage versus small craniotomy with closed-system drainage for chronic subdural hematomas. METHODS: From January 2016 to December 2018, 75 patients who were treated with burr hole drainage and small craniotomy with closed system drainage for the symptomatic chronic subdural hematoma were enrolled. Pre and postoperative computed tomography (CT) were used for radiologic evaluation. The choice of procedure was decided by preoperative CT images. RESULTS: 60 patients out of 75 patients underwent burr hole drainage, whereas 15 patients underwent small craniotomy. The overall postoperative recurrence rate was 16%. The recurrence occurred in 8 patients out of 60 patients in burr hole drainage group (13.3%) and 7 patients out of 15 patients in small craniotomy group (46.7%). The number of days of hospitalization was 10.3 days in burr hole drainage group and 15.7 days in small craniotomy group. CONCLUSION: Burr hole drainage would be sufficient to evacuate chronic subdural hematoma with lower recurrence rate, but small craniotomy was also needed in some cases such as hematoma has solid portion or multiple septum.

Disappearance of Arachnoid Cyst after Burrhole Trephination: Case Series / 대한신경손상학회지

We report 3 cases of arachnoid cysts (ACs) that completely disappeared after burr hole drainage, without cyst fenestration into the subarachnoid space or cystoperitoneal shunt. The first patient was a 21-year-old female with an AC of the right cerebral convexity, found incidentally. After endoscopic AC fenestration was performed, the patient complained of persistent headache. Two-month postoperative brain imaging revealed reaccumulated AC and associated multi-stage subdural hematoma. Burr hole drainage was performed to resolve the chronic subdural hematoma (CSDH). Three months later, brain computed tomography showed that the CSDH and the AC had disappeared. The second patient was an 11-year-old male who had a history of trauma 1 month prior to presentation at the clinic. Brain magnetic resonance imaging revealed an AC in the left sylvian fissure with CSDH. We performed burr hole drainage to treat the CSDH first. Subsequently, the AC as well as the CSDH disappeared. The third case was an AC of the right parietal convexity, found incidentally. Only burr hole drainage was performed, following which, the AC disappeared. This case series shows that an AC can disappear naturally after rupture into the subdural space by trauma or the burr hole procedure.

Spontaneous Intracranial and Spinal Subdural Hematoma: A Case Report / 대한신경손상학회지

Spinal subdural hematoma (SDH) is rarely reported, and their simultaneous occurrence with intracranial SDH is even more rare. A 67-year-old male patient with a history of posterolateral fusion to treat an L2 burst fracture came to our outpatient clinic due to an inability to walk by himself over the previous 3 weeks. A neurological examination revealed that the patient was alert with occasional confusion and slight motor weakness in the lower extremities. Brain and lumbar spine magnetic resonance imaging (MRI) was then performed. A brain MRI revealed a large subacute SDH along the right cerebral convexity and falx cerebri with midline shifting, and a spine MRI revealed a right side-predominant subacute SDH extending from L4 to S1. For treatment, burr hole trephination of the intracranial SDH and fluoroscopy-guided lumbar puncture of the spinal SDH were performed and resulted in a favorable outcome. This is a report of a rare case of spontaneous intracranial and lumbar spine SDH. We include a review of the current literature and a discussion of the pathogenesis of this condition in this report.

How to Treat Chronic Subdural Hematoma? Past and Now

Treatment of chronic subdural hematoma (CSDH) is relatively straightforward, however, there is still some debate regarding the best strategy for treatment. The most practical recommendations of up to date were identified by a review of literature. The author reviewed the literature on CSDH management from the past to now to identify the best methods. Till 1970s, craniotomy was the most commonly used method. Burr hole (BH) became the most preferred method from 1980s. In 1977, twist drill (TD) craniostomy was introduced. Closed system drainage after a BH or a TD became the most frequently used surgical method. Although nonsurgical treatment is often successful, trephination has more advantages, such as rapid resolution of the symptoms and short period of hospitalization. Nonsurgical treatment is possible in asymptomatic patients with a small CSDH. For the symptomatic patients with CSDH, trephination is the treatment of choice, either by BH or TD. In gray zone between surgery and medical treatment, shared decision making can be an ideal approach. For the recurrent CSDHs, repeated trephination is still effective for patients with a low risk of recurrence. If the risk of recurrence is high, additional management would be helpful. For the refractory CSDHs, it is necessary to obliterate the subdural space.

Coma secundario a síndrome del trefinado / Coma due to syndrome of the trephined

El síndrome del trefinado o craniectomizado abarca manifestaciones neurológicas asociadas a la depresión del flap cutáneo y se distingue del síndrome postraumático por su reversibilidad con el tratamiento reparador del defecto craneano. El coma no es una forma habitual de presentación. Comunicamos un caso de presentación atípica en un hombre de 36 años de edad con antecedente de craniectomía descompresiva, que presentó un cuadro de deterioro neurológico profundo atribuible al síndrome del trefinado, el cual revirtió tras la craneoplastía. En la fisiopatología del síndrome intervienen trastornos cerebrovasculares, metabólicos, hidrodinámicos del líquido cefalorraquídeo e hiperdinamismo de las estructuras encefálicas. El gold standard terapéutico es la craneoplastía. Se requieren estudios de mayor peso estadístico para determinar el tiempo quirúrgico apropiado.

The syndrome of the trephined or craniectomized is commonly referred as neurological manifestations associated to skin flap depression and reversible after craneoplasty, which allows its differentiation from post-traumatic syndrome. We present the case of a male patient, 36 years old, with history of decompressive craniectomy. He evolved with sudden neurological worsening associated to syndrome of the trephined and recovery after craneoplasty. Physiopathology of the syndrome involves cerebrovascular, metabolic and cerebrospinal fluid hydrodynamic disturbances as well as parenchymal hyperdynamic mechanisms. Cranioplasty is the gold standard treatment. Still, studies with statistical power are needed to assess correct surgical timing.

Presentation of the trepanned skull labelled MO-90, found in the Avar cemetery on the territory of settlements Ómoravica-Kopláló in Serbia / Presentación de cráneo trepanado etiquetado MO-90, encontrado en el cementerio de Avar en territorio de los asentamientos Ómoravica-Kopláló en Serbia

SUMMARY: The most prominent issues in paleopathology concerning skull lesions are skull trepanation and artificial deformation of the skull. From the very beginnings of this scientific field, these two groups of alterations have been the focus of interest. Since the second half of the 19th century, countless pathologists, surgeons and ethnologist have dealt with this issue. The interest is still great. Nevertheless, numerous questions regarding skull trepanation and artificial deformation are yet to be answered. The first trepanned skull finds were discovered in France and Hungary. The finds in Hungary are interesting because a large number of trepanned skulls were found in a relatively small area. On the skull remains found in the grave discovered in the Òmoravica-Koplaló cemetery and labelled MO-90, left of the Sutura sagittalis there is a hole about 1cm in diameter. There are no pathological lesions along the edge or around the hole.

RESUMEN: Los temas más destacados en la paleopatología con respecto a las lesiones del cráneo son la trepanación y la deformación artificial éste. Desde los comienzos en esta área científica, estos dos grupos de alteraciones han sido el foco de interés. Desde la segunda mitad del siglo XIX, un número importante de patólogos, cirujanos y etnologistas se han enfocado e interesado en este tema. Sin embargo, aún existen preguntas y numerosas dudas sobre la trepanación del cráneo y la deformación artificial. Los primeros hallazgos de cráneos trepanados se descubrieron en Francia y Hungría. Los hallazgos en Hungría son interesantes debido a que es un área relativamente pequeña, pero fueron encontrados una gran cantidad de cráneos trepanados. En los restos de cráneos encontrados en la tumba del cementerio Òmoravica-Koplaló y etiquetados como MO-90, a la izquierda de la sutura sagital se observó un foramen de aproximadamente 1 cm de diámetro. No hay lesiones patológicas a lo largo del margen, tampoco alrededor del foramen.

Quistectomía conservadora mediante trepanaciones múltiples: reporte de un caso / Conservative cystectomy by multiple trepanations: report of a case

En la actualidad los procedimientos quirúrgicos han evolucionado con la intención de ser lo más conservadores posible, dando pie a una regeneración fi siológica más rápida y completa. La extirpación de quistes de gran tamaño de los maxilares mediante descompresión y marsupialización ha demostrado obtener excelentes resultados, siendo éste un procedimiento que permite evitar un amplio abordaje quirúrgico, aunque generalmente requiere un segundo tiempo para reconstruir el defecto. La quistectomía conservadora mediante múltiples trepanaciones de acceso, permite la eliminación del cuerpo patológico por completo sin la necesidad de un segundo procedimiento quirúrgico. La excelente cicatrización ósea fi siológica y adecuado reposicionamiento y soporte de tejidos blandos sin necesidad de utilizar membranas, son logrados gracias a los puentes óseos que se mantienen entre las trepanaciones, los cuales brindan soporte además de mantener células osteoprogenitoras. Se presenta caso clínico de enucleación conservadora de quiste periapical de gran tamaño y extracción de canino retenido en paciente masculino de 12 años de edad mediante trepanaciones múltiples (AU)

Nowadays the surgical procedures have evolved aiming to be as conservative as possible, resulting in a faster physiological regeneration. The removal of large maxillary cysts using decompression and marsupialization has proved to have excellent results, is this a procedure that avoids the use of large surgical access, although a second procedure is generally needed to completely remove the lesion. Conservative cystectomy using multiple access trepanations allows the complete elimination of the cyst without the need for a second surgical intervention. Excellent physiological bone healing and adequate soft tissue reposition without the need of grafting material and membrane is achieved thanks to the osseous bridges between the multiple trepanations, which gives support for soft tissue and provides osteoprogenitor cells. A clinical case of conservative enucleation of a large radicular cyst is presented as well as the extraction of a retained canine in a 12-year-old male patient using multiple trepanations (AU)

Rapid Spontaneous Resolution of Contralateral Acute Subdural Hemorrhage Caused by Overdrainage of Chronic Subdural Hemorrhage

BACKGROUND: Since the first report of a rapidly resolved subdural hemorrhage (SDH) in 1986, few additional case reports have been presented in the literature. CASE REPORT: An 82-year-old female patient presented with a SDH over the left convexity. The SDH was removed via catheter drainage through a burr hole trephination. Post-operative computed tomography (CT) following 300 mL drainage from the chronic SDH demonstrated a newly developed SDH along the right convexity. A follow-up CT performed 2 hours later revealed an unexpected significant resolution of the acute SDH. CONCLUSION: The spontaneous resolution of acute SDH is believed to result from redistribution by washout of the hematoma by cerebrospinal fluid dilution. However, its exact pathophysiology is not well understood. When surgical evacuation is considered in acute SDH, conservative management should also be considered because spontaneous resolution of hemorrhage remains a possibility.

Craniotomy and Membranectomy for Treatment of Organized Chronic Subdural Hematoma / 대한신경손상학회지

We report the case of a patient with organized chronic subdural hematoma (OCSH) that was treated with craniotomy. A 72-year-old man was admitted with a complaint of a drowsy mental status after a generalized tonic-clonic seizure. A brain computed tomography scan acquired at a local hospital revealed a large chronic subdural hematoma (CSDH) in the left frontoparietal lobe. The patient had not experienced head trauma and had been taking clopidogrel due to angina. A neurosurgeon at the local hospital performed single burr hole trephination in the left frontal bone and drained some of the hematoma. Brain magnetic resonance imaging performed upon transfer to our hospital showed a large OCSH with a midline shift to the right side, revealing a low, heterogeneous signal on T2-weighted images (WI) and an isodense signal on T1-WI. We performed craniotomy and membranectomy to achieve adequate decompression and expansion of the brain. Following this, the patient recovered completely. Our findings support that neurosurgeons should consider the possibility of organization of a CSDH when selecting a diagnosis and treatment plan.

Burr Hole Drainage with Urokinase Irrigation for the Treatment of Acute Subdural Hematoma: A Case Report / 대한신경손상학회지

We describe the case of a patient with an acute subdural hematoma (SDH) that was removed using urokinase irrigation after burr hole trephination in a limited situation where craniotomy was not possible. A 90-year-old woman was admitted to our hospital with a stuporous mental status. Computed tomography (CT) scans revealed a chronic SDH, and a burr hole procedure was performed. The patient's postoperative progression was good until the third day after surgery when we found that the acute SDH had increased on CT scans. The patient's guardian refused further surgery, and thus we drained the blood from the hematoma by injecting urokinase through a drainage catheter. We used urokinase for two days, and removed the catheter after confirming via CT scans that the hematoma was almost alleviated. The patient recovered gradually; she was discharged with few neurological deficits.

Complications Following Burr Hole Craniostomy and Closed-System Drainage for Subdural Lesions / 대한신경손상학회지

OBJECTIVE: Burr hole craniostomy and closed-system drainage (BCD) is a common surgical procedure in the field of neurosurgery. However, complications following BCD have seldom been reported. The purpose of this study was to report our experiences regarding complications following BCD for subdural lesions. METHODS: A retrospective study of all consecutive patients who underwent BCD for presumed subdural lesions at one institute since the opening of the hospital was performed. RESULTS: Of the 395 patients who underwent BCD for presumed subdural lesions, 117 experienced surgical or nonsurgical complications. Acute intracranial hemorrhagic complications developed in 14 patients (3.5%). Among these, 1 patient died and 5 patients had major morbidities. Malposition of the drainage catheter in the brain parenchyma occurred in 4 patients, and opposite-side surgery occurred in 2 patients. Newly developed seizures after BCD occurred in 8 patients (2.0%), five of whom developed the seizures in relation to new brain lesions. Eighty-eight patients (22.3%) suffered from nonsurgical complications after BCD. Pulmonary problems (7.3%) were the most common nonsurgical complications, followed by urinary problems (5.8%), psychologic problems (4.3%), and cognitive impairments (3.8%). CONCLUSION: The incidence of complications after BCD for subdural lesions is higher than previously believed. In particular, catastrophic complications such as acute intracranial hematomas and surgical or management errors occur at rates that cannot be ignored, possibly causing medico-legal problems. Great caution must be taken during surgery and the postoperative period, and these complications should be listed on the informed consent form before surgery.