Finely Controlled Hypotension during Brain Surgery in Ethiopia

Brain surgery being done with controlled hypotension at Ayder Comprehensive Specialized Hospital

At Ayder Comprehensive Specialized Hospital, the university medical center for Mekelle University in Ethiopia, our experience with finely controlled hypotension during brain surgery for both adults and children has reduced the need for blood transfusion by half. 

In many underdeveloped African countries the surgical treatment of brain tumors is often very late in the course of the disease due to delay in the patient seeking treatment, having a diagnostic study to find the tumor, and being scheduled for surgery as many university centers have long waiting lists. Such is the situation we are in Ethiopia. These large brain tumors, often 10 centimeters or more in diameter, can require massive transfusion during the surgery to remove or reduce them. 

Large meningioma which has risk for high blood loss during surgery

The Department of Neurosurgery in the School of Medicine at Mekelle University in a close partnership with our Department of Anesthesia has been working on creating sustainable safe controlled hypotension techniques to reduce our blood loss during brain tumor surgery in adults and children at Ayder Comprehensive Specialized Hospital.  Thanks to the donation of a high quality intravenous perfuser by a diaspora American anesthesiologist and the cooperation of the university to gain stocks of Isoflurane  inhalation agent and Propofol intravenous agent as well as in house training together we have significantly reduced blood loss leading to much less transfusion during brain surgery. End tidal CO2 is kept at 4.5 to 5% and mean arterial blood pressure maintained at 65-70 mm/Hg.

brain surgery under controlled hypotension

Interpersonal Violence and Head Injury in Tigray:Public Health Issue

The head injury problem especially that due to interpersonal violence in Tigray is a growing and significant problem which requires a public health approach.

3d CT scan of man suffering depressed fracture of skull from stone injury

Research published by Fasika et al showed that 24.8% of head injury admissions came from interpersonal violence from 2011 to 2014 which was before neurosurgery was permanently established at Ayder Comprehensive Specialized Hospital. Currently we are seeing about 10 patients a day and operating on 2 to 3 every day. Most of the surgeries we do are for depressed fractures caused by stone injury received in interpersonal violence. The age range of these injuries ranges from preschool to the eighth decade of life. We know there is a cultural proclivity to this type of injury but it is not well studied.

The hospital burden of head injury includes about 19% of adult ICU admissions and bedspace and 25% of pediatric ICU admissions and bed space. Our average daily census on the adult ward is 5 for head injury and on the pediatric ward also 5. The length of stay can vary from 24 hours to months with most of the surgical patients requiring a least a 5 days stay in the hospital.This burden acts to limit the care those suffering from other maladies can receive.

At the current time there is no public health or government plan to try to prevent these injuries.The World Health Organization has created a Violence Prevention Alliance which sees interpersonal violence as requiring a public health approach.

This public health approach to violence prevention seeks to improve the health and safety of all individuals by addressing underlying risk factors that increase the likelihood that an individual will become a victim or a perpetrator of violence.

The approach consists of four steps:

1 To define the problem through the systematic collection of information about the magnitude, scope, characteristics and consequences of violence.
2 To establish why violence occurs using research to determine the causes and correlates of violence, the factors that increase or decrease the risk for violence, and the factors that could be modified through interventions.
3 To find out what works to prevent violence by designing, implementing and evaluating interventions.
4 To implement effective and promising interventions in a wide range of settings. The effects of these interventions on risk factors and the target outcome should be monitored, and their impact and cost-effectiveness should be evaluated.

 

Diagram of WHO prevention plan

By definition, public health aims to provide the maximum benefit for the largest number of people. Programs for the primary prevention of violence based on the public health approach are designed to expose a broad segment of a population to prevention measures and to reduce and prevent violence at a population-level.

I propose that Mekelle University put together a multidisciplinary team consisting of not only physicians but also social scientists, public health professionals, police and prosecutors ( this was previously discussed with the head of the Tigray police who was interested), and government stakeholders. This type of investigation and policy development is exactly the type of activity which the University with all its resources and knowledge base should be tackling.

Lumbar Myelomeningocoel Surgery in Northern Ethiopia

This a review of some of the principals I follow when performing myelomeningocoel surgery in young infants in Northern Ethiopia. More than a third of all the neurosurgery operations is made up by this pediatric neurosurgical condition at our hospital.

It is estimated by the World Health Organization that over 300,000 children suffer neural tube defects which results in improper formation of the spinal cord, spine, and brain leading to absence of bowel, bladder, and sexual function control, spinal deformity, reduced mental development, and paralysis. More common in underdeveloped countries then in developed countries, the occurrence has been mostly strongly related to preconception maternal folate deficiency and some genetic factors. Unfortunately in Ethiopia there are thousands of these children born every year, we see several a week in our clinic at Ayder Comprehensive Specialized Hospital at the Mekelle University College of Health Sciences in Northern Ethiopia.

Myelomeningocoel is a disorder where the neural tube which develops in the first month after conception from a flat plate of specialized tissue fails to fully close into a tube. This results in neural elements being exposed directly to the atmosphere or only a thin membranous layer. The lowest nerves below the defect often do not completely form leading to paralysis in the lower extremities and difficulties with the functions normally performed by the sacral nerve roots involving the bladder, rectum, and sexual organs.

Pre-Operative Assessment

Pre-operatively many of these children come to the hospital from long distances in poor nutritional condition. If they weigh less than 3 kilograms we delay surgery until they reach this weight because of problems with temperature control in the operative and immediate post-operative period. Children who have cerebrospinal fluid leaks, chronic bleeding from the neural placode, progressive macrocephaly, symptomatic hydrocephalus, symptomatic Arnold-Chiari symptoms such as weak cry, weak upper extremities or multiple pneumonias from aspiration, or meningitis are given priority. Because of the large number of cases and limited resources there is often a several month waiting period for those in stable condition with well epithelialized neural tube defects.

To undergo surgery they must be fit for general anesthesia with normal hemoglobin, kidney function, cardiovascular status and be free of active infection. Ultrasound evaluations of the head to assess for hydrocephalus and of the abdomen to assess the kidneys is routinely done.

They are kept nothing per oral (NPO) for several hours before surgery and started on pediatric maintenance intravenous fluid containing glucose during this time which is continued in the operating room and after until the child is breast-feeding normally.

We do not routinely prepare blood for the surgery unless the child has a low hemoglobin/hematocrit preoperatively. If so then a pre-operative transfusion will be given.

Surgery

The child is placed under general inhalation anesthesia using isofluorane rather then halothane is the most common anesthetic agent used in Ethiopia. We use a electric heater in the room, warm the saline irrigation used during the case, intravenous fluid heaters, and keep the child covered as much as possible to avoid hypothermia which can occur easily in our mountain environment.

Pre-operative ceftriazone at 50mg/kg is given for prophylaxis and continued for 48 hours post-operatively.  This is given not just to prevent wound infection but also because these children are at risk of developing post operative pneumonia from the co-existing Arnold-Chiari malformation also present.

myelom-closure1

The child is placed in prone position with an intravenous fluid bag under the chest and under the groin which leaves the abdomen free of pressure thus reducing venous bleeding during the surgery. In the picture is seen a child with a large membranous lumbar myelomeningocoel. The large size taking up most of the width of the back and the mostly membranous covering predicts that closure will be difficult.

myelom-closure2

The dissection is done under loupe magnification. The neural elements are dissected free of the epithelium, fat, scar tissue, and fibrous bands. In the picture above the spinal cord with attached neural placode and the lumbar dorsal fascia have been identified.

myelom-closure3

In many cases the lumbar dorsal fascia can be carefully dissected at the lateral extant of the wound and then reflected medially to be closed as a dural layer. In the picture above this “dural” layer is closed first by several interrupted 3-0 vicryl sutures and the oversewn with a running suture.

myelom-closure4

Key to being able to close the wound is mobilizing the subcutaneous fascia superiorly and inferiorly and bilaterally. This must be generously done by careful digital dissection to free up the skin edges. It is generally better to over mobilize then undermobilize to reduce tension on the skin closure. If the a primary midline closure cannot be done then the primary skin fascial incision can be extended to superior and inferior z-plasty incisions which must be longer than the original incision. Alternatively a rhomboid type flap can also be used. It is important in the post-operative period to support the flap by giving supplemental oxygen, maintaining hydration, checking the post-operative hemoglobin/hematocrit, and avoid undo pressure on the flap. Most of the cases can be primarily closed.

Despite the best techniques, about 20 percent of cases have some type of wound problem which can range from mild stitch abscess or dehisicience to severe dehisicience. I always tell the surgical residents that we close the dura thinking that should the flap come apart with a sound dural closure we have a good chance for secondary healing.

myelom-closure5

This was a very large myelomeningocoel that we attempted to close with a modified z-plasty.  Unfortunately a week after surgery there was some necrosis and breakdown. However, with aggressive daily wound care and good nutritional support a good result was obtained by secondary intention healing over a month’s time because of the good dural closure underneath.

Careful monitoring of the head circumference, anterior fontanel, eye movements, mental status, and feeding is necessary in the immediate and later post-operative period. Most of these children will go on to develop progressive hydrocephalus requiring a second operation for insertion of a ventricular peritoneal shunt. A few of them if they have persistent stridor, weak cry, aspiration will need to go undergo an upper cervical laminectomy and decompression of the brainstem for treatment of the Arnold-Chiari malformation.