A successful potential technique to reduce prolonged hospital stay of patients associated with the use of continuous drainage following surgical evacuation of a chronic subdural haematoma ( SDH )

The Sri Lanka Journal of Surgery, August 2013 Volume 31, No. 2, Page 21-24 DOI: http://dx.doi.org/10.4038/sljs.v31i2.5958


Introduction
A Subdural Hematoma (SDH) is a common neurosurgical condition that often requires surgical intervention.It is a type of intracranial hemorrhage that occurs beneath the dura (essentially, a collection of blood over the surface of the brain), and may be associated with concurrent brain injuries.A SDH usually forms after rupture of a bridging vein.
It is further categorized into three stages based on the duration.An acute SDH is a rapid collection of blood clot found below the inner layer of the dura but external to the brain and arachnoid membrane.The next two stages, subacute and chronic, may develop with untreated acute SDH.In general, the subacute phase begins 3-7 days after the acute injury.The chronic phase begins about 2-3 weeks after the acute injury.The incidence of chronic subdural hematoma is about 5 per 100000 per year in the general population and higher in those aged 70 years or older [1].
SDH is considered to be associated with high mortality and morbidity rates, even with the best medical and neurosurgical care [2].Surgical evacuation via craniotomy is often considered in patients with an acute SDH, thicker than 5 mm (as measured with axial computed tomography scanning), and who have any neurologic signs such as lethargy, change in mental status or focal neurologic deficits.Bullock et al reported that "an acute SDH with a thickness greater than 10 mm, or a midline shift greater than 5 mm on computed tomography scan should be surgically evacuated, regardless of the patient's GCS score [3].
Various surgical methods have been recommended for the treatment of SDH and are under research.One time burrhole drainage and continuous closed drainage are methods

A successful potential technique to reduce prolonged hospital stay of patients associated with the use of continuous drainage following surgical evacuation of a chronic subdural haematoma (SDH)
H.K.A. Ruwanchinthani 1 , H. Kularathne 2 1. Medical Officer, Neuro-Surgical Unit, National Hospital of Sri Lanka, Colombo.2. Consultant Neurosurgeon; Neuro-Surgical Unit, National Hospital of Sri Lanka, Colombo.

Technique
Before terminating the closed continuous subdural drain system, our usual protocol has been to wait until the drain is 10cc or less.Usually, this has taken between 7 and 10 days.In our patient we removed the drain 48 hours after operation.Informed consent was obtained before the procedure, which was done in the ward under aseptic conditions, with the patient lying supine.The drain was removed by applying negative pressure through gradual suction using a 5cc syringe.This was an air tight procedure -a volume of 12 cc of clear fluid followed by 4cc of altered blood was removed and there was no active bleeding noted at this point.After removal of the drain sutures were applied to the scalp.

Investigations
Two NCCT scans were performed, one before and after suction.The patient was observed for twenty four hours after removing the drain.He made a complete recovery on the third post operative day and was discharged on oral medication.
With this procedure of suction of fluid with negative pressure before removing the drain we were able to facilitate early recovery as it helped brain expansion mainly in an elderly patient with cortical atrophy which is demonstrated in the NCCTs below.In the post operative pre-aspiration NCCT (figure 2.1), a left sided white opacity suggestive of recent bleeding, probably following surgery, and an air filled space is demonstrated.By contrast, in the post operative post aspiration NCCT (figure 2.2), expansion of the brain is noted after drainage of air and blood.
On discharge from the hospital, the patient's symptoms were relieved, the GCS was 15/15 and his right side weakness had improved.At regular follow up in the neurosurgical clinic for six months, he did not have post operative infection, recurrence of SDH or deterioration of consciousness.Similarly, in a study done in Cambridge, Santarious-et-al, found that use of an irrigating drain with a burr hole was associated with lower recurrence rate, better neurological status and lower mortality at six months compared with no drain [6,7].
In the aforementioned studies only one time drainage or continuous drainage was tested, where as in the new method suggested, a combination of closed continuous drainage for forty eight hours was followed by removal of the drain applying negative pressure.As found in the study done in Turkey, the usual hospital stay of 7.9 days with continuous drainage, this new technique has the potential to reduce hospital stay to 3 days.
On the other hand, a more recent comparative study done in New Delhi, India, did not find a statistically significant difference in recurrence rates and concluded that continuous drainage of an SDH did not offer any advantage over simple burr-hole drainage [1].This emphasizes that continuous drainage only prolongs hospital stay, and this new method of removing the drain after forty eight with negative pressure may be more economical.It has a better prognosis and, most importantly, reduces duration of hospital stay, which is cost effective for the patient as well as the healthcare provider.

Discussion
A variety of surgical techniques have been described for chronic SDH.Trephination is a common method that is being used.In this procedure, a liquefied chronic SDH is commonly treated with drainage through a single or two burr holes.The burr holes are placed so that conversion to a craniotomy is possible, if needed.A closed drainage system is sometimes left in the subdural space postoperatively.In a case series by Mori and Maeda, 89.4% of patients with chronic subdural hematoma (SDH) who were treated with a closed drainage system had a good recovery and 2.2% worsened.Old age, preexisting cerebral infarction, and subdural air after surgery correlated with poor brain expansion [4].This highlights that removal of subdural air with negative pressure application helps in brain expansion -an observation which is confirmed in our new technique.
A study on controversies in SDH: continuous drainage versus one time drainage done in the department of neurosurgery in Turkey has concluded that burr-hole and continuous drainage (CD) therapy for SDH is superior to the burr-hole and one time drainage (OTD) method due to shorter time of hospitalization and the reduced rate of recurrence [5].The post operative hospitalization period was 7.9 days in the CD group and 17 days in the OTD group.Recurrence developed in two cases (6.8%) in the