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7/29/2019 1 Complications

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Man age ment of Hyd roc ephalu s Complications

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Complications:

1. Obstruction due to malposition of the device or inaccurate selection of componentswith excessive resistance in the system. (McCullough, 1995)

2. CSF and shunt Infections: (Oram, 2006)Shunt infections can present in a number of ways:

a. Meningitis.b. An indolent infection with a chronic inflammatory response leading to

shunt obstruction.

c. Local soft tissue infection around the shunt hardware with woundbreakdown and/or purulent discharge.

d. Infection within the peritoneal cavity that presents with abdominal pain,shunt obstruction and/or an accumulation of fluid within the peritoneal

cavity. (Frim and Gupta, 2006)

Immediate CSF infection is rare, but most septic incidents occur within the first two

months of insertion or revision of a shunt. They usually manifest with obstructivesymptoms, fever, cellulitis, and leukocytosis. The most reliable therapy is complete

shunt removal with temporary external drainage and appropriate systemic antibiotics. Anew device can be inserted after obtaining at least two consecutive negative cultures 48hours apart (McCullough, 1995)

Etiology:

a. Coagulase-negative staphylococci and Staphylococcus aureus cause about 75% ofshunt infections.

b. Gram-negative bacilli cause 20% of shunt infections.c. The remainder is caused by Micrococcus species, Streptococcus species, fungi

(usually Candida species) and anaerobes such as Propionibacterium acnes.

(Oram, 2006)

Cause: Contamination of the apparatus at the time of surgical placement is the most

common mechanism by which shunts become infected. Only 20% of infections due toskin flora are caused by an organism present before surgery. Shunt infections are also

caused by retrograde infection originating at the distal end of the shunt. The abdomen

is the usual source, and infection can occur through either peritonitis resulting from

penetration of the bowel by the distal end of the catheter or arising spontaneously may

cause a secondary ascending infection of the shunt. Approximately 80% of shunt

infections occur within 3 months of shunt placement or revision. Patients may present


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with shunt malfunction and associated symptoms such as headache, vomiting,

irritability and lethargy. Fever and meningeal signs may not be present.(Oram, 2006)

Diagnosis of shunt infection

Clinical: Patient presents with :

1. fever or with evidence of shunt malfunction.2. Low grade fever between 37.5 and 38.8C.3.poor feeding.4. failure to thrive.5. Irritability.6.bulging fontanelle.Once the cranial sutures are closed, as in older children and adults, a somewhat different

spectrum of symptoms occurs, such as:

7. fever.8. Headaches.9. vomiting not associated with meals.10.lethargy.11.Abdominal pain and tenderness or evidence of local inflammatory reactions at the

wound sites or along the shunt tract also provide specific clues as to the possibility

and location of infections.

Investigations :

1. Radiological: Patients should have a radiological evaluation like:a. anteroposterior and lateral skull, chest, abdominal x-ray.b. CT scan.

2. The Shunt Tap:a. It's performed to obtain CSF for

study and to avoid contamination

of the CSF or the shunt itself byskin flora.

b. A mask and sterile gloves must beworn and the area over the shunt

reservoir is shaved, prepped with

Betadine or Hibiclens solution,

then draped with sterile adhesive

The shunt tap. (George & Kureshi,

1997)


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paper drapes.

c. A 23- gauge butterfly needle is passed percutaneously into the reservoir.d. Testing shunt flow dynamics will vary depending on the shunt system. The

testing sequence begins with occlusion of the distal flow which allows for

measurement of the CSF flow from the ventricular catheter and of intracranial

pressure, along with sampling of CSF. Next, the proximal flow should be

occluded and a column of fluid run distally to assess adequacy of valve

function and peritoneal tubing patency.

e. CSF obtained should be tested for glucose, protein, cell count and differential,and culture and antibiotic sensitivity. (George & Kureshi, 1997)

Treatment: The presence of a shunt infection proven by CSF Gram stain or culture

requires :

a. Appropriate antibiotics: Consists of a combination of antimicrobial therapy andsurgery. Initial empiric antimicrobial therapy consists of an antistaphylococcal

antibiotic, such as nafcillin or vancomycin. A third-generation cephalosporin and

an aminoglycoside are added if abdominal symptoms are present or the Gram-

stain smear of the CSF shows Gram-negative bacilli. Once the antimicrobial

susceptibilities of the organism are known, empiric therapy is adjusted to target

the causative organism(s). The use of intrathecal antibiotics in the treatment of

CSF shunt infections is controversial. Many antibiotics, including vancomycin,

have poor CSF penetration when given parenterally, even in the presence ofinflamed meninges. Therefore, direct installation of the antibiotic into the

meninges has been used to improve delivery. However, the pharmacokinetics of

intraventricular antibiotics are not well studied, and the potential exists for

neurotoxicity and chemical ventriculitis. Use of intraventricular antibiotics should

be reserved for infections that have failed standard treatment. Frequent CSF

cultures are used to monitor response to therapy. If the shunt was left in place

and cultures remain positive after several days, removal of the shunt with EVD

placement should be considered. The duration of antibiotic therapy is usually 10

to 14 days following sterilization. Several factors, such as the infecting organism,time to sterilization and presence of distal complications, should be considered

when determining length of therapy. A new shunt can be placed once the CSF is

sterile, but there are no data as to the optimal timing of shunt replacement.

(Oram, 2006)

Surgical strategy


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Shunt infections are manifested by three scenarios:

1. Catheter contamination witha mild or fulminant

ventriculitis: the entire

shunt hardware should beremoved, an EVD placed

for the duration of antibiotic

therapy, and then

replacement of the shunt. If

there is a fulminant

ventriculitis (i.e.,

intraventricular purulence or Gram-negative infection), the EVD should be set up

so that irrigation of the ventricular system can be performed. This will allow for

intraventricular antibiotic therapy and/or continuous irrigation to debride purulent

material or help wash out bacteria when CSF production is diminished in the face

of Gram negative infection.

2. Superficial wound infectionwith or without CSF

contamination: Superficial

wound infections should be

treated by removal of the

shunt hardware and

placement of an EVD. If the

CSF cultures are negative

after 3 days of antibiotics,

the shunt can be replaced in

a new location. However, if the CSF cultures are positive, then the usual 10-day

antibiotic course is given and the shunt replaced after the infection is resolved. If

there is only a suture abcess, the suture can be removed and the wound treated

locally with topical antibiotics.3. Peritoneal infection

manifested as a loculated

cyst or frank peritonitis with

or without CSF infection: in

the presence of an

abdominal infection, the

(George & Kureshi, 1997)




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shunt can be removed from the abdomen and left with the distal end externalized

when the CSF studies are negative. Once again, if the CSF studies are positive,

removal of the entire shunt system and placement of an EVD is necessary.

Generally, we prefer to treat all infections by the prompt removal of the infected

hardware, placement of a temporary external ventricular drain (EVD), and thendelayed replacement of the shunt after the infection is resolved.

Placement of an external ventricular drain

The placement of an EVD is performed with the patient under general anesthesia (Figure

3). Induction is accomplished using intravenous thiopental, and anesthesia is maintained

using opiates and inhalation agents such as forane. Close monitoring of body

temperature is maintained and hypothermic measures are instituted to treat pyrexia;

warming lights are used if hypothermia is present. The patient is positioned so that thetotal shunt system as well as a new site for the ventricular catheter are accessible.

The key to the procedure is to remove all original hardware that can be safely removed.

The site of the previous cranial incision is reopened and the shunt hardware exposed.

The ventricular catheter should be disconnected from the distal tubing, and then the

valve and peritoneal catheter removed. When the distal system has been in place for

several years, the tubing may become frail and prone to breakage, making necessary the

use of one or two small additional incisions to remove the hardware. Next, the original

ventricular catheter is removed. When ventricular catheters are adherent and difficult toremove, we use the 1.2-mm ventriculoscope to visualize the lumen of the tubing and

cauterize adherent choroid plexus in order to avoid intraventricular bleeding (Figure 4).

Usually, a soft passing technique can be utilized

to place the new 25-cm ventricular drainage

catheter when the old tract is used. If a new site

is needed, the preferred ventricular catheter

placement is via a frontal approach. The entry

point on the skull should generally be 2 cmanterior to the coronal suture and 2 cm lateral to

the midline. The catheter tip trajectory should be

aimed at the ipsilateral medial canthus and

anterior to the tragus. Typically, a depth of 4 to 6

cm will place the catheter in the frontal horn, just

Placement of the EVD from a

frontal or a posterior approach. The

tubing is tunneled to a separate exit

site and connected to a closed

drainage system. (George &

Kureshi, 1997)


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anterior to the foramen of Monro. CSF samples should be sent for routine studies.

The excess tubing is then tunneled subcutaneously at least 4 to 5 cm toward a frontal

exit site for ease of nursing care and to avoid having the patient lie on the tubing. A

sterile Becker or Connell closed drainage system is connected. The wound should be

irrigated with copious amounts of bacitracin solution and a meticulous two-layer closureis performed with 3-0 or 4-0 Vicryl and 3-0 or 4-0 nylon. An adherent occlusive

dressing is applied.

An EVD should not be routinely changed. In the event that the drain becomes

secondarily contaminated, a new EVD should be placed as described above.

Externalization of distal shunt tubing

The procedure can be performed in a clean treatment room or preferably in the operating

room. Depending on the age of the patient, the local anesthesia using 0.5% to 1%

lidocaine/epinephrine mixture with or without a standby sedation protocol is used. The

area around the clavicle should be prepped with Betadine or Hibiclens and draped with a

sterile adhesive drape. The shunt tubing is palpated as it courses over the clavicle and

the skin is then infiltrated with the local anesthetic.


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A small 1- to 2-cm transverse incision is made down through the epidermis. The tubing

is located again by palpation, and gentle blunt dissection is continued to fully expose the

tubing. We prefer to use monopolar cautery to perform dissection since the shunt tubing

is resistant to damage by the coagulation current. Approximately 3 or 4 cm of the distal

portion of tubing is removed and then sectioned once exposed (Figure 5B). Prior to

removal of the distal tubing, aspiration of any peritoneal fluid or cyst fluid should be

attempted by using a 10- or 20-cc syringe connected to a 19-gauge blunt needle, and the

aspirated fluid sent for culture (Figure 5C). This maneuver provides a diagnostic testwhile treating a cyst and removing the foreign body. The proximal tubing is connected

to a Luer connector, which is then connected to a closed disposable external drainage

system (Becker and Connell have systems available) in which the level of drainage can

be measured and drainage bags changed in a sterile fashion (Figure 5D). Usually, a

single layer closure will suffice using an interrupted nylon suture.

Prevention of ventriculoperitoneal shunt infections

Externalizing a VP shunt:

A, ultrasound of abdomen revealing an infected peritoneal pseudocyst at the distal tip of the

peritoneal catheter and the site of externalization below the clavicle.

B, dissection exposing the shunt tubing.

C, sectioning of shunt tubing and aspiration of peritoneal contents using the distal tubing.

D, the proximal shunt tubing is connected to a closed sterile drainage system. (George & Kureshi,

1997)


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1. A diligent skin preparation with Betadine or Hibiclens solution protocol.2. The use of iodine-impregnated sterile adhesive paper drapes.3. The gentle handling of tissues.4. Meticulous hemostasis.5. Use preoperative antibiotics aimed principally to cover staphylococcal species. It's

given 1 hour prior to skin incision.

6. Shunt components are removed from the sterile packaging following completeskin preparation and draping and are kept in a bacitracin solution until used.

Contact of the shunt tubing with the skin is avoided and tubing exposed to thesurgical drapes is wrapped in bacitracin-soaked sponges. (George & Kureshi, 1997)

3. Injury to an abdominal organ occurs in 0.4% of patients. This often presents as aninfectious-obstructive episode, but extrusion of the catheter via the intestinal tract

has been observed. (McCullough, 1995)4. Mechanical failure: If the volume of drained CSF is inadequate the problem of

overdraining or underdraining occurs. It results from an inappropriate opening

pressure of the shunt system for the individual patient (Trojanowski , 2009):

a. Overdrainage: It may cause :i. Subdural haematomas may occur as a direct result of overdrainage,

causing further difficulties in treatment.

ii. Slit ventricle syndrome (SVS) describes a longer term complicationof overdrainage that occurs in approximately 1% of shunted

paediatric patients.

The aetiology is unclear but has been attributed to

a. Overshunting.b. Intracranial hypertension.c. Periodic shunt malfunction.d. Decreased intracranial compliance. The ventricles are small on CT scan,

but the pressure within them can be very high. The child complains of

headaches and vomiting.

Treatment: The low-pressure valve will consequently be changed to a medium

or high-pressure resistance valve, or an antisyphon device. In extreme

situations a subtemporal decompression craniectomy has been performed, with

mixed results. (May, 2001)


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b. Underdrainage: This results in enlarged ventricles and necessitateschanging to a lower pressure valve. (May, 2001)

5. Obstructive complications will inevitably occur. The majority involve the distalportion of the device. Patients with high CSF protein values at the initiation of

therapy may require several shunt revisions during the first postoperative year. After

about the sixth year, patients treated in infancy may present with obstruction due toaxial somatic growth and relative shortening of the peritoneal catheter. Obstructionmay also result from rarely encountered peritoneal pseudocysts, ascites due to

peritoneal absorptive failure, peritoneal adhesions, internal debris, or breakage and

disconnection of shunt components. The use of modern kink-resistant silicone tubing

with avoidance of older, delicate, spring-reinforced peritoneal catheters has virtually

ended the occurrence of disconnection and catheter migration. A small group ofpediatric and adolescent patients with CSF diversion receives considerable attention

because of frequent bouts of vomiting, headache, and deterioration of consciousness.The patients tend to have small ventricles, diminished extraventricular CSF spaces,

and a thick skull. In my experience less than 4% of treated patients were suspected

of having this syndrome. The majority of these actually had true proximal shuntobstruction solved by appropriate catheter replacement in the frontal horn. In the

remainder, corrective procedures such as augmenting valve resistance andsubtemporal craniectomy may be required to manage symptoms and prevent

decompensation. (McCullough, 1995)

6. Shunt failure is mostly due to suboptimal proximal catheter placement.Occasionally, distal catheters fail. Suspect infection if the distal catheter is

obstructed with debris. Abdominal pseudocysts are synonymous with low-grade

shunt infection.( Sahrakar, 2002)7. Shunt disconnection: the technique of securing all connections with a nonabsorbable

suture tied across the connector can help prevent disconnection. (Klinge, 2008)8. Aspiration: The patients either have a full stomach or have been vomiting and are at

risk for aspiration. A modified RSI (Rapid Sequence Induction and Intubation)should be considered for tracheal intubation. To avoid further increase in ICP,blunting the stimulus of laryngoscopy and intubation will be necessary. Wise use of

opioids, lidocaine, and/or intravenous anesthetics can be considered. However over-administration of these agents can cause a decrease in BP, leading to inadequate

cerebral perfusion pressure. (Aliason & Koh, 2012)9. Latex Allergy: Children with a history of myelomeningocele are at significantlyincreased risk for latex allergy. Many children with myelomeningocele also havehydrocephalus. It's reported that the prevalence of sensitization to latex may be as

high as 64% in children with spina bifida. Allergy to latex is a type 1 IgE-mediatedreaction clinically manifested as urticaria, angioedema, bronchospasm, and

anaphylactic shock. The best way to prevent latex allergy is to prevent latexexposure.


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Cause: Patient may expose to latex in latex gloves, tape, medication vials, blood

pressure cuffs or other latex-containing products.

Treatment is through: Removing all latex agents, Secure the airway, FIO 2 100%Epinephrine as needed, Reduce or discontinue volatile, anesthetics as dictated by,

hemodynamics, IV fluid boluses to support blood pressure, Corticosteroids,

Antihistamines. (Aliason & Koh, 2012)10.Surgical Trauma: May be direct or indirect. Rapid surgical decompression ofhydrocephalus can lead to rupture of the cortical bridging veins and SDH, or upward

herniation of the brainstem causing bradycardia, irregular respirations, or ECGchanges. (Aliason & Koh, 2012)

11.Subdural hematoma/upward herniationRapid surgical decompression.

Rapid lowering of open EVD. (Aliason & Koh, 2012)

12.Intrathoracic trauma (heart, lung, and great vessels) can occur when the passersheath is tunneled across the chest wall and toward the abdomen.

Cause: VP shunt passer sheath inadvertently tunneled into chest cavity.Treatment: Depending on which organ has been damaged, the staff must beprepared to treat hemorrhage, tamponade, and pneumothorax. (Aliason & Koh,

2012)

13.Venous Air Embolism (VAE)VAE can occur at any time, especially during placement of a ventriculoatrial shunt. To

help prevent VAE, the anesthesiologist can keep the surgical site lower than the

level of the heart (if possible), mechanically ventilate the patient, maintain high

venous pressure, and remove air from IV tubing and solutions.Treatment: FIO 2 100%, Reduce or discontinue volatile anesthetics as dictated by

hemodynamics, Aspirate air if central line is in situ, IVFs/vasopressors to maintain

BP, Valsalva, Surgical site below the heart and LLD, if possible, CPR if cardiac

arrest. (Aliason & Koh, 2012)

Complications associated with ventriculostomy.

Endoscopic ventriculostomies carry risks that are mainly related to damage of structures

near the floor of the third ventricle. Endoscopic ventriculostomy can be acutelycomplicated by arrhythmias, asystole, hypertension, hemorrhage and bradycardia.

(Aliason & Koh, 2012)

1. Injury to the basilar artery or its branches. Hemorrhage, stroke, or falseaneurysmal formation may be seen following injury to the basilar artery.

Treatment:


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Call for help FIO 2 100% Decrease or D/C volatile anesthesia IVFs and vasopressors as needed Transfusion of blood products as neededManage elevated ICP until

craniotomy(Aliason & Koh, 2012)

2. Subdural hematoma from ventriculardecompression. (figure 2)

3. Meningitis with or without CSFleakage.

4. Arrhythmias or bradycardia/asystoleCause:

Stimulation of the floor of the thirdventricle by the endoscope

High speed irrigation fluid Rapidly increasing ICP Vagal response to surgical or other

manipulation (i.e., pressure on eye)

Venous air embolismTreatment:

Stop stimulating floor of 3rd ventricle andto stop irrigation fluid.

If arrhythmia does not resolve , treat supportively according to rhythm disturbance. FIO 2 100%.(Aliason & Koh, 2012)

5. Hypertension:Cause: Catecholamine release due to surgical stimulation or Local surgical effects

on third ventricle floor.Treatment:

Repeat BP measurement to verify accuracy Deepen anesthesia if needed Stop stimulating floor of third ventricle and irrigation fluid Raised ICP may require mannitol, furosemide, and/or hyperventilation Urinary catheter if bladder is distended(Aliason & Koh, 2012)

Fig. 2. Coronal T2W MRI sequence showing

bilateral subdural hygromas and subcutaneous

collection post endoscopic 3rd ventriculostomy

for hydrocephalus. The stoma later blocked anda shunt was placed. (Najjar & Turkmani, 2011)


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6. Complications due to trauma ofHypothalamus: (fig:3) it may lead to

SIADH or DI, Temperature regulation

problems (can be mistaken for

malignant hyperthermia), Post-op

trance-like state (differential postop

agitation/delirium). (Aliason & Koh,

2012)

7. Complications due to trauma of Cranialnerves: 3rd and 6th nerve palsies have beenreported. (Aliason & Koh, 2012)

8. fever. Due to an increase CSF temperatures dueto the use of a cold light source and a monopolar

coagulation in the confined volume of the third

ventricle.9. Short-term memory loss: Since the proceduremay affect the hypothalamus and the areas of the

mamillary body, which are responsible for

memory. However, given time, an individual

usually recovers from any short-term memory

loss following endoscopic third ventriculostomy. (Hydrocephalus Association, 1997)

10.How to avoid complications :-

1. Fenestration should be performed at the most transparent portion of the floor.

2. Fenestration should be performed in the midline of the patient.

3. Blunt perforation is preferable to cautery or the use of sharp instruments. (Crone,

2006)

(Tsang & Leung 2012)Complications of EVD include hemorrhage, misplacement, dislodgement,

disconnection, blockage, and, most significantly, infection.

External ventricular drain infection

EVD-related infections may lead to further serious complications such as ventriculitis,meningitis, cerebritis, brain abscess and subdural empyema. An infected EVD

contraindicates immediate permanent shunting and may therefore delay definitive CSF

Fig. 3. Coronal T1W MRI sequence showing a

small left thalamic lesion with hydrocephalus.

The child underwent endoscopic 3rd

ventriculostomy and biopsy. Symptomatic

hydrocephalus was thus treated and the lowgrade tumor proven at biopsy was stable and

followed with imaging. (Najjar & Turkmani,

2011)


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diversion. It significantly prolongs hospital stay and increases cost. Patients in the

infected group also suffered from more severe neurological damages .

Empirical antibiotics with good CSF penetration should be given to cover the commonoffending organisms. The commonly used agents are cephalosporins and rifampicin.

Intraventricular vancomycin may be used for resistant organisms. Revision of the EVD

at a different site should be considered if CSF diversion or ICP monitoring is stillrequired.

Causative organisms:

1. Coagulase-negative Staphylococcus is consistently reported to be the most commonbacteria isolated in patients with EVD-related infections, accounting for up to 47%of infected cases.

2.Enterococcus.3.Enterobacter.4. Staphylococcus aureus.5. Gram-positive organisms are classically associated with ventriculitisRisk factors1. Subarachnoid hemorrhage (SAH) and Intraventricular hemorrhage (IVH):

This has been postulated to be the result of frequent manipulations of the drainage

system for flushing blocked EVD, the infusion of fibrinolytic agents, and the higherchance of EVD revision in these patient with hemorrhages. The risk of infection was

found to be 6 to 10% higher in patients with hemorrhages.2. Craniotomy and other neurosurgical procedures: The conduction of craniotomies

or other neurosurgical procedures were found to be a risk factor for EVD-related

infections when compared with patients who had received EVD alone.3. Venue of insertion and skill level of surgeon: Many authorities advocated the

operating theatre as a preferred venue for EVD insertion. However, some surgeons

demonstrated separately that inserting EVDs in the intensive care units, emergency

rooms or neurosurgical wards was not inferior in terms of infection risks or othercomplications. The location of insertion did not appear to affect the risk of infection

provided that strict aseptic technique was used. There was also no significant

difference amongst EVDs that were performed by neurosurgical trainees, consultantsor neuro-intensivists. (Tsang & Leung 2012)

4.

Subcutaneous catheter tunnel: Friedman & Vries, 1980 have devised a newventriculostomy technique that involves tunneling the ventricular catheter through

the scalp, between the dermis and the galea. The average duration of drainage was6.2 days. There were no infections subsequent to the insertion of the ventricular

catheter in patients. (Friedman & Vries, 1980).5. Duration of drainage: The literature was very much divided on the issue of whether

and how the duration of external CSF drainage may affect the risk of infection. The

recent researches demonstrated no association between the risk of infection and the


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duration of drainage. The timing of EVD related infections appeared to follow a

normal distribution during the first five postoperative days, and the majority of

infections occurred between day two and day 11. So early infections may arise frominitial inoculations, which developed into detectable infections after variable

incubation periods of around five days. A delayed peak of infection has also been

observed after day 20, but the small number of reported cases rendered confirmationdifficult. Based on the belief that the risk of infection would increase with prolonged

EVD, some authorities have advocated elective revisions of EVD after a fixed

interval of, say, five days. However, the review by Park et al on 595 patients withEVD insertions found that the daily infection rates would plateau after day 4 post-

insertion, and remain steady beyond day 10.6. Manipulation of the EVD system: Manipulations and opening of the otherwise

closed EVD system for CSF sampling or flushing may introduce microorganisms

and potentially cause infection.

7. Prophylactic antibiotics: There is no consensus as to what and for how long itshould be given. Responders in Europe favored a single dose of antibiotics givenimmediately before the operation, while those from Asia and North America tend tocover also the whole period of post-operative drainage. The use of prophylactic

antibiotics was found to significantly reduce the risk of EVD- related infections8. Coated ventricular catheter: The underlying rationale is that coating the surface of

the catheter with special materials or antibiotics may decrease bacterial colonizationand thus prevent infection. The findings were controversial depending on the coating

material used. Antibiotics-impregnated catheter is an important development. (Tsang& Leung 2012)

How to avoid complications

Complications are unavoidable but we can reduce their frequency. To achieve this goal

reliable diagnosis of NPH should be made, appropriate selection of patients with high

likelihood of effectiveness of shunting. Meticulous execution of implantation plays an

important role in complication avoidance. Too long or too short ventricular catheter,

placed sub optimally in the ventricular system, mechanical damage of the shunt system

by inadequate handling or bad instruments, too long operation time, violation of

strictly aseptic technique increase the risk of shunt dysfunction or infection.

(Trojanowski , 2009)


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