Atlas of Procedures in Neonatology, 4th Edition

Miscellaneous Procedures

48

Tapping Ventricular Reservoirs

Secelela Malecela

The subcutaneous ventricular access device (Fig. 48.1) is used as a temporary measure to drain cerebrospinal fluid (CSF) in preterm infants with posthemorrhagic hydrocephalus while awaiting permanent ventriculoperitoneal (VP) shunt placement (1,2,3,4,5,6,7).

A ventricular reservoir is often inserted in preterm infants who are too small or too unstable to have a VP shunt. A ventricular reservoir also allows for drainage and clearing of the initial CSF, which is bloody and has a high protein content, thus decreasing the risk of shunt blockage (5,6 and 7).

The reservoir is usually tapped immediately following placement by the neurosurgeon to ensure proper placement and to drain excess CSF (5). Subsequent taps are performed in the neonatal intensive care unit (NICU), aiming to remove enough CSF to prevent further ventriculomegaly and maintain normal head growth (5,6,8).

  1. Indications
  2. Rapidly increasing head circumference, more than 1 cm/week
  3. Clinical signs of raised intracranial pressure evidenced by a full or tense anterior fontanelle, separation of the sutures, apnea and bradycardia, poor feeding and vomiting
  4. Ultrasound or radiologic evidence of progressive ventriculomegaly
  5. Contraindications
  6. Low circulating blood volume
  7. Cellulitis or abrasion over the reservoir site
  8. Sunken fontanelle or overlapping sutures
  9. Severe coagulopathy
  10. Equipment
  11. Mask, cap, sterile gloves
  12. Standard infant lumbar puncture set
  13. Povidine–iodine surgical scrub and prep solution
  14. Aperture drape
  15. Scalp-vein needle (25- or 27-gauge)
  16. 20-mL syringe
  17. Precautions
  18. Use strict aseptic technique.
  19. Maintain continuous cardiorespiratory monitoring during the procedure.
  20. Do not use local anesthetic.
  21. Do not place intravenous lines on the same side of the scalp.
  22. Do not shave the operative area.
  23. Always use a fresh site for insertion of the needle with every tap.
  24. Avoid puncturing the bottom of the reservoir.
  25. Technique
  26. Infant should be restrained and comfortable, with the head in neutral position.
  27. Clip any long hair that interferes with the surgical area but do not shave the operative area.
  28. Clean skin over the reservoir and a radius of 5 cm of the surrounding skin using surgical scrub. Use light but firm contact. Clean for 5 to 10 min.
  29. Dry with blotting pads.
  30. Don mask and cap.
  31. Scrub hands and put on sterile gloves.
  32. Paint area with povidine–iodine solution and allow area to dry.
  33. Drape area while maintaining patient visibility.
  34. Insert scalp-vein needle at an angle of 30 to 45 degrees through the skin into the reservoir bladder (Fig. 48.2).
  35. Aspirate fluid at a rate of 1 to 2 mL/min. Remove no more than 10 to 15 mL/kg. Some authors advocate letting the CSF drain spontaneously, rather than aspirating, in order to reduce fresh bleeding into the ventricles (9).
  36. Remove needle and hold firm pressure for 2 minutes, until CSF leakage from the skin stops.
  37. Clean area with sterile saline to remove the povidine–iodine.
  38. Remove the restraints.
  39. Send CSF sample for culture, cell count, glucose, and protein. This should be done every 3 days. If fluid

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is dark and bloody, it is reasonable to send only a culture sample.

 

FIG. 48.1. McComb reservoir. Ventricular access device: side (top) and front views (bottom).

  1. A Successful Tap
  2. At the end of the procedure the anterior fontanelle should be soft and flat (not sunken) and the cranial bones should be approximated well at the sutures.
  3. If sufficient volume is removed, the fontanelle may be full 24 hours later, but the sutures should not split apart.
  4. If the fontanelle remains slack, the interval for tapping may be lengthened to every other day and/or the amount of CSF removed at each tap reduced.
 

FIG. 48.2. Tapping of the reservoir.

TABLE 48.1 Complications of Ventricular Reservoir Drainage

Problem (Incidence)

What To Do

Hyponatremia (20%–60%)

Monitor serum electrolytes every other day and supplement sodium intake.

Hypoproteinemia (15%)

Ensure adequate protein intake. Monitor serum albumin weekly.

Infection (0%–8%)

A combination of intravenous and intrareservoir antibiotics may rarely be successful. Removal of the reservoir is usually necessary.

Subgaleal CSF collection (0%–9%)

Percutaneous aspiration of fluid using a different needle at the same time as the reservoir is tapped.
Tap larger volume of CSF from the reservoir or increase frequency of taps to reduce pressure.

CSF leaks through incision (0%–3%)

Increase frequency of reservoir taps.

Ventricular access device occlusion (0%–10%)

Replace reservoir.

Trapped contralateral ventricle (6%)

Place second reservoir.

Fresh bleeding into the ventricle (0%–40%)

Prevent by using 25- or 27-gauge needle, aspirate slowly or let CSF drain spontaneously rather than aspirating.

Bradycardia, pallor, hypotension (rare)

Stop aspiration. Infuse 10–15 mL/kg of normal saline IV rapidly. Remove a smaller volume at a slower rate at next tap.

Skin breakdown over reservoir (rare)

Avoid abraded skin when tapping the reservoir. Avoid excoriating skin while prepping site.

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  1. Follow-Up
  2. Assess clinical response to taps, daily head circumference, and weekly cranial ultrasonography.
  3. Interval between taps may range from twice a day to once every 2 to 3 days.
  4. Taps should be continued until the infant weighs 2 kg and is a suitable candidate for shunt placement or until the hydrocephalus resolves.
  5. Complications

See Table 48.1 (1,2,3,4,5,6,7,8,9,10).

References

  1. Whitelaw A, Cherian S, Thoresen M, Pople I.Posthaemorrhagic ventricular dilatation: new mechanisms and new treatment. Acta Paediatr. 2004;44:11–14.
  2. Benzel EC, Reeves JP, Nguyen PK, Hadden TA.The treatment of hydrocephalus in preterm infants with intraventricular hemorrhage. Acta Neurochir. 1993;122(3–4):200–203.
  3. De Vries LS, Liem KD, Van Dijk K, et al.; Dutch Working Group of Neonatal Neurology.Early versus late treatment of posthemmorhagic ventricular dilatation: results of a retrospective study from five neonatal intensive care units in The Netherlands. Acta Paediatr. 2002;91(2):212–217.
  4. Heep A, Engelskirchen R, Holschneidr A, Groneck P.Primary intervention for posthemorrhagic hydrocephalus in very low birth weight infants by ventriculostomy. Childs Nerv Syst. 2001;17(1–2):47–51.
  5. Firm DM, Scott RM, Madsen JR.Surgical management of neonatal hydrocephalus. (Review). Neurosurg Clin North Am.1998;9(1):105–110.
  6. McComb JG.Management of intraventricular hemorrhage in neonates. Western J Med. 1984;769–770.
  7. Gaskill SJ, Marlin AE, Rivera S.The subcutaneous ventricular reservoir: an effective treatment for posthemorrhagic hydrocephalus.Childs Nerv Syst. 1988;4(5):291–295.
  8. Hudgins RJ, Boydston WR, Gilreath CL.Treatment of posthemorrhagic hydrocephalus in the preterm infant with a ventricular access device. Pediatr Neurosurg. 1998;29(6): 309–313.
  9. Moghal NE, Quinn MW, Levene MI, et al. Intraventricular hemorrhage after aspiration of ventricular reservoirs. Arch Dis Child.1992;67:448–449.
  10. Weparin BE, Swift DM.Complications of ventricular shunts. Techn Neurosurg. 2002;7(3):224–242.