Surgery for Craniofacial Malformations

Stephen A. Schendel MD, DDS, FACS¹

Nai Yi Sun MD²

Mary Laughlin MD²

Louise Furukawa MD²

¹SURGEON

²ANESTHESIOLOGISTS

SURGICAL CORRECTION OF CRANIOSYNOSTOSIS

SURGICAL CONSIDERATIONS

Description: Premature fusion of cranial sutures, or craniosynostosis, causes various well-recognized patterns of cranial vault and facial deformities. Rarely, these are related to conditions such as Crouzon, Apert, Saethre-Chotzen, and Pfeiffer syndromes. Single or multiple sutures can be involved, the most common being the sagittal suture. This condition is called scaphocephaly, in which the cranial vault is bitemporally narrow, with AP elongation. Anterior or posterior plagiocephaly involves a single coronal suture or lambdoid suture and is characterized by flattening of the forehead on the affected side. Oxycephaly (“tower-head deformity”) involves bilateral coronal sutures, with a flat, high forehead, whereas brachycephaly also involves the cranial base sutures and results in bitemporal bulging, midfacial hypoplasia, an anterior open bite, and hypertelorism. These patients may have severe sleep apnea and can pose a challenge for airway management. Trigonocephaly (triangular head shape; Fig. 12.8-1), with a keel-shaped forehead and hypoteloric tendency, involves the metopic suture.

Surgical correction of these craniofacial anomalies requires a combined plastic surgery and neurosurgery team approach involving the release or resection of the affected suture and simultaneous correction of the asymmetric skull by bone-flap repositioning or advancement. Frontal/orbital abnormalities are addressed with bifrontal craniotomy and forehead advancement, along with advancement of the supraorbital bar (fronto-orbital advancement; Fig. 12.8-2). For example, in plagiocephaly, because of the unilateral coronal synostosis, the frontal bone is retruded and the superior orbital rim is elevated and retruded on this side. Craniectomy is performed, the forehead is removed, the involved coronal suture is resected, and the supraorbital bar is cut above the orbit and down to the lateral orbital wall across the midline. The bar is bent, advanced on the involved side—sometimes up to 1.5 cm—and
fixed in this position. Additional bone strips are taken from the posterior cranium and split for use as graft material; the other bone pieces are replaced and fixed with wires, suture, or restorable plates, which is the most common method now.

Figure 12.8-1. Skull shape abnormalities in metopic synostosis: Regions of reduced bone deposition (—). Regions of compensatory increased bone deposition (+++). (From Belfrey ME, Pershing JA, et al: Surgical Treatment of Metopic Synostosis. In: Pershing JA, Jane JA, eds. Neurosurgical Clinics of North America. WB Saunders, Philadelphia: 1991, used with permission.)

Figure 12.8-2. Fronto-orbital advancement. A: Lines of osteotomy for forehead and supraorbital bar advancement. B: Fronto-orbital advancement in a tongue-in-groove manner and fixation with wires. (Reproduced with permission from Aston SJ, Beasley RW, Thorne CH, eds: Grabb and Smith’s Plastic Surgery, 5th edition. Lippincott-Raven, Philadelphia: 1997.)

Patient positioning, type of headrest, and incision all vary, depending on location of the suture abnormality. If the deformity is mostly posterior (e.g., a sagittal or plagiocephaly case), a prone approach with biparietal or midsagittal incision can be used and may be done endoscopically in the younger infant. Resection of the involved suture and barrel staving of the cranium, with grafting for reshaping, works well. Reconstruction as above usually is accomplished at ˜3-6 mo of age. Brain mass doubles in size the first 6 mo and triples by 3 yr of age, when ˜80% of the brain growth is completed (the driving force for cranial vault growth).

All procedures are extradural. Dural tears, if they occur, are repaired to prevent CSF leak and CNS infection.

In the syndromic cases, the cranial synostosis deformity is treated similarly to the procedure described, usually before the age of 12 mo, with a view to midfacial advancement of the primary dentition at maturity either by LeFort III or by monobloc advancement with or without distraction. (See p. 1443 LeFort Osteotomies, and p. 1442 Major Secondary Craniofacial Surgical Procedures.)

Postsurgical orthopedic distraction devices like the Delaire mask also can be used to encourage midfacial growth. The syndromic cases may require repeat craniotomy and reshaping at a young age if signs of ↑ ICP appear. Other synostotic cases also should be monitored for ↑ ICP and the need for urgent secondary craniotomy. Marchac and Renier detected ↑ ICP in 13% of single-suture synostosis and 42% of multisuture synostosis. ↑ ICP may increase the risk of dural breach during craniotomy 2° cranial bone resorption and thinning.

Blood loss can be significant at first incision through the vessel-rich scalp. Rainey clips are applied immediately to minimize blood loss. In anticipation of major blood loss, transfusion should be started with the first incision. Severe life-threatening blood loss can occur if the sagittal sinus is breached, and neurosurgical repair must be accomplished quickly. Elevation of the bone flaps usually causes diffuse bleeding, which is stopped easily with irrigated bipolar cautery and thrombin-soaked sponges. It is useful to have the patient in the reverse Trendelenburg position from the start. Diffuse bleeding at the cut bone edges and over the bone surfaces can be further controlled with bone wax. Focal bleeding from around the orbit and in the temporal fossa region subperiosteally also can be controlled with
bone wax. A LeFort/monobloc component to the surgery increases blood loss, especially during the initial mobilization of the facial segment. Local anesthetic with epinephrine injected, and/or on sponge packs for pressure, will control the diffuse mucosal bleeding. BP control is also paramount. Electrocautery and Ligaclips to larger vessels (e.g., descending palatine pedicles) may be necessary.

Variant procedure or approaches: In older children (> 2 yr), split cranial bone grafts may be required to correct defects caused by bone-flap advancement. Excision of skull segments is commonly accompanied by rigid fixation.

Usual preop diagnosis: Craniosynostosis (sagittal, coronal, metopic, lambdoid); syndromes such as Apert and Crouzon syndromes; ↑ ICP

▪ SUMMARY OF PROCEDURE

Position	Usually supine; prone for correction of lambdoidal suture synostosis or posterior sagittal synostosis. If entire cranial vault reshaping (multiple sutures), special padded occipital-cheek headrest, because pin fixation is not safe until > 2 yr.
Incision	Usually bicoronal, biparietal, Meisterschnitt, midsagittal
Special instrumentation	Horseshoe headrest, usually pediatric; occasionally, Gardner tongs; Midas Rex craniotomy; resorbable plates and screws
Unique considerations	Control of ICP — spinal drain may be placed. Blood in room, if transfusion anticipated.
Antibiotics	Pediatric: cefazolin 25 mg/kg q 8 h, or vancomycin 10-15 mg/kg q 6 h, and cefotaxime 25-50 mg/kg q 6 h for oropharyngeal contamination and following dural tears
Surgical time	2-6 h
Closing considerations	Blood loss with Rainey clip removal. Full head-wrap dressing causes head/neck movement → bucking.
EBL	200-800 mL; may be formidable.
Postop care	ICU: 1-2 d (further transfusion often necessary in first 2 h to replace drain losses)
Mortality	0.6-1.6%
Morbidity	Major complications: 14.3% Bone infection: 3-7% Meningitis CSF leak: 4.5% ↑ ICP Air embolus: < 1% Blindness: < 1% Massive bleeding: < 1% Venous thrombosis Neurologic injury: Rare
Pain score	4

▪ PATIENT POPULATION CHARACTERISTICS

Age range	2-24 mo (primary correction)
Male:Female	1:1
Incidence	Nonsyndromic: 1/10,000 births (most sporadic; few familial patterns) Crouzon syndrome: 1/25,000 Apert syndrome: 1/100,000
Etiology	Idiopathic; however, some are associated with specific genetic conditions (e.g., Crouzon and Apert syndromes). Other cases may be 2° ↓ brain growth.
Associated conditions	Hydrocephalus; ↑ ICP; mental retardation; airway problems; ocular abnormalities; exotropia (29% Crouzon or Apert syndrome); lagophthalmus; exorbitism

ANESTHETIC CONSIDERATIONS

PREOPERATIVE

Patients may have craniofacial anomalies—particularly Apert and Crouzon syndromes—which are associated with midface hypoplasia, obstructive sleep apnea, and in some cases difficult intubation. Apert syndrome may also be associated with congenital cardiac anomalies. Hence, detailed preop evaluation is necessary. Children with singlesuture craniosynostosis are usually healthy. Surgery is often performed between 3 and 6 mo of age, preferably when the infant weighs > 5 kg.

Respiratory	Patients with long-standing upper-airway obstruction due to choanal atresia, mandibular and maxillary hypoplasia, or other causes, may have chronic hypoventilation and hypoxia and may experience episodes of apnea. If the patient has Sx of acute URI, delay elective surgery at least 2 wk. The presence of fever, cough, and abnormal chest auscultation necessitates surgical cancellation and pediatric consultation. Tests: As indicated from H&P
Airway	Be aware of other congenital anomalies affecting the patient’s airway, such as Apert, Klippel-Feil, Goldenhar, Pierre Robin, Treacher Collins, or Crouzon syndromes. Review any previous anesthetic records for patient to gain insights into appropriate airway management (e.g., Video laryngoscope or FOI may be necessary). Consider elective tracheostomy under local anesthesia in patients with severe airway abnormalities.
Cardiovascular	Consider the coexistence of congenital cardiopulmonary anomalies, particularly in patients with Apert syndrome (autosomal dominant trait, craniosynostosis, midface hypoplasia, syndactyly of hands and feet, ASD, and VSD). Preop evaluation of a patient with a known or suspected heart defect should include thorough H&P, ECG, Hct, baseline O₂ sat, and echocardiogram. For children with Sx of cardiac dysfunction or those requiring cardiac medication, it is advisable to consult with a pediatric cardiologist to optimize the patient’s condition prior to surgery. Tests: Preop EKG indicated for patients with CHD, CXR, ECHO; others as indicated from H&P.
Neurological	If only the sagittal suture is involved, ICP is usually normal. If more than one suture is involved, brain growth will be impaired, the patient will be developmentally delayed, and intracranial HTN may be present. Older patients presenting for repair are more likely to show signs and symptoms of elevated ICP. Syndromic craniosynostosis often have associated hydrocephalus.
Hematologic	Surgery in early infancy (< 9 mo) is common; thus, allowable blood loss is small; blood transfusion usually is required. Tests: Hct; PT; PTT; T&C blood
Laboratory	Other tests as indicated from H&P
Premedication	Patients > 9-10 mo old may benefit from premedication with midazolam (0.5 mg/kg po). Antibiotic prophylaxis for CHD may be warranted. Consult latest AHA guidelines.

INTRAOPERATIVE

Anesthetic technique: GETA. Anticipate possible difficult airway. Heat OR to 78-80°. Forced air warmer. Heat all fluids to body temperature.

Induction	Surgery for craniectomies is extradural. Either mask induction with N₂O and inhalational agent or iv induction is suitable for the infant with a normal airway. If ICP is suspected to be elevated, consider mild hyperventilation after loss of consciousness. For a difficult airway, intubation may be facilitated by using Video laryngoscope or FOI while patient is anesthetized and spontaneously ventilating. In rare situations, tracheostomy, under sedation and local anesthesia, may be necessary. Consider suturing ETT to prevent accidental extubation in prone cases, as unsutured endotracheal tubes can slip through tape due to pooling of oral or nasal secretions.
Maintenance	Maintenance anesthesia with inhalational agent or balanced (iv) anesthesia, and long-acting muscle relaxant should be adequate. Surgery may be prolonged. Control of ICP may be necessary (see below). A remifentanil infusion 0.1-0.2 mcg/kg/min provides profound intraop analgesia, BP control, and allows for rapid awakening.
Emergence	Prompt awakening to allow neurological evaluation is an important goal. Excessive facial edema due to prolonged surgery or high blood loss requiring large-volume fluid replacement, particularly in patients with preoperative sleep apnea, may require the patient to remain intubated postoperatively. Check for presence of air leak around ETT in patients with significant facial edema to determine readiness for extubation.
Blood and fluid requirements	Anticipate large blood loss. IV× 2 (as large as possible) LR @: 4 mL/kg/h – 0-10 kg + 2 mL/kg/h – 11-20 kg + 1 mL/kg/h – > 20 kg (e.g., 25 kg = 65 mL/h) Warm all fluids. Humidify gases.	Have 1-2 U PRBC or whole blood available in the room. Consider splitting PRBC into aliquots preoperatively to minimize donor exposure. Use freshest compatible PRBC available for infants to minimize risk of hyperkalemia. Consider antifibrinolytics such as Tranexamic acid (loading dose 50 mg/kg, followed by infusion of 5 mg/kg/h) to decrease intraoperative blood loss and blood transfusion needs. Use LR for replacing deficit, maintenance, and 3rd-space fluid loss. Replace blood loss with colloid and PRBC mL for mL. Warm all fluids administered. Significant blood loss begins with scalp incision; allowable blood loss is small so that it is important to begin transfusion early before hypovolemia occurs. Estimation of intraoperative blood loss may be difficult because of significant loss of blood onto surgical drapes and gowns. EBV for an infant in this age group is 80 mL/kg. Monitor for signs of coagulopathy and transfuse FFP and cryoprecipitate platelets as needed. Avoid NS (acidosis, ↑ bleeding) in children < 5 yr. Beware of ↑ K⁺ and ↓ Ca⁺⁺ associated with massive transfusion.
Control of ICP	Hyperventilation Osmotic diuretic Loop diuretic	In some cases, it may be desirable to ↓ ICP. This can be accomplished by ↑ ventilation (PaCO₂ = 25-30 mm Hg), diuretics (furosemide 0.5-1 mg/kg iv).
Monitoring	Standard monitors (Appendix D-1). + Arterial line ± CVP line ± Precordial Doppler ± Urinary catheter	Arterial cannulation for BP, monitoring of ABG, Hct, electrolytes, etc., ↑ K⁺ and ↓ Ca⁺⁺ are most common following transfusion with whole blood or FFP. VAE has been reported during craniectomies in infants; hence, a precordial Doppler and CVP line will be helpful. CVP may be particularly helpful in the infant with marginal cardiovascular status for volume assessment and drug administration. Close attention to ETCO₂ and, if available, ETN₂ monitoring is useful. If VAE is suspected, the surgical field should be flooded and the head lowered immediately. CVP may be particularly helpful in the infant with marginal cardiovascular status for volume assessment and drug administration and if peripheral iv access is limited. Precordial or esophageal stethoscope is useful in cases where the patient is turned 180° or in cases of marginal pulmonary function.
Positioning	[check mark] and pad pressure points [check mark] eyes	Positioning depends on surgical approach; most are performed with patient supine. The head-up position is commonly used to help decrease venous pressure and blood loss.
Complications	Oculocardiac reflex (OCR) ↓↓ HR and ↓↓ BP VAE	Notify surgeons. If does not resolve, give atropine 0.02 mg/kg iv (min 0.1 mg). Be prepared to make prompt Dx of VAE (↓ ETCO₂, change in Doppler sounds, ↑ ETN₂ ↓ O₂ sat, ↓ BP, ↑ HR) and Rx: notify surgeons, flood wound, ± head down, aspirate CVP, ± vasopressors. Minimizing head-up position, avoiding hypovolemia, and introducing PEEP can help to prevent VAE.

POSTOPERATIVE

Complications

Hypovolemia with ↓ BP

Hypothermia

Airway complications

Inadequate volume replacement may result in ↓ BP and acidosis. [check mark] Hct to establish need for further fluid or blood therapy. Coagulopathy may develop postoperatively, check coags to establish need for blood component therapy.

Excessive facial edema, history of a marginal airway preoperatively, or severe obstructive sleep apnea with sensitivity to opioids may necessitate maintenance of a secure airway postoperatively

Pain management

Parenteral opioids and acetaminophen (see p. E-4).

Tests

Follow-up Hct postop

Transfuse to keep Hct ≥ 30%.

Suggested Readings

1. Chiaretti A, Pietrini B: Safety & efficacy of remifentanil infusion in craniosynostosis repair in infants. Ped Neurosurg 2002; 36(1):55-6.

2. Cladis F, Grunwaldt L, Losee J; Anesthesia for plastic surgery. In: Davis PJ, Cladis FP, Motoyama EK eds. Smith’s Anesthesia for Infants and Children, 8th edition. Elsevier, Philadelphia: 2011, 821-41.

3. Davies DW, Munro IR: The anesthetic management and intraoperative care of patients undergoing major facial osteotomies. Plast Reconstr Surg 1975; 55(1):50-5.

4. Farbod F, Kanaan H, Farbod J: Infective endocarditis and antibiotic prophylaxis prior to dental/oral procedures: latest revision to the guidelines by the American Heart Association published April 2007. Int J Oral Maxillofac Surg 2009; 38(6):626-31.

5. Goobie SM, Meir PM, et al: Efficacy of transexamic acid in pediatric craniosynostosis surgery: a double-blind, placebocontrolled trial. Anesthesiology 2011; 114(4):862-71.

6. Guzman R, Lobby JF, Schendel SA, Edwards MS: Fronto-orbital advancement using and en bloc frontal bone craniectomy. Neurosurgery 2011; 68(1 Suppl Operative):68-74.

7. Harris MM, Yemen TA, Davidson A, et al: Venous embolism during craniectomy in supine infants. Anesthesiology 1987; 67(5):816-19.

8. Hayden Gephart MG, Woodard JI, Arrigo RT, et al: Using bioabsorbable fixation systems in the treatment of pediatric skull deformities leads to good outcomes and low morbidity. Childs Nerv Syst 2012 Oct 26. [Epub ahead of print]

9. Huang M, Mouradian WE, Cohen SR, et al: The differential diagnosis of abnormal head shapes: separating craniosynostosis from positional deformities and normal variants. Cleft Palate Craniofacial J 1998; 35(3):204-11.

10. Ko EW, Chen OK, Tai IC, Huang CS: Fronto-facial monobloc distraction in syndromic craniosynostosis. Three-dimensional evaluation of treatment outcome and facial growth. Int J Oral Maxillofac Surg 2012; 41(1):20-7.

11. Koh JL, Gries H: Perioperative management of pediatric patients with craniosynostosis. Anesthesiol Clin 2007; 25(3):465-81.

12. Marchac D, Renier D, Jones BM: Experience with the “Floating Forehead.” Br J Plast Surg 1988; 41(1):1-15.

13. Muhling J: Surgical treatment of craniosynostosis. In: Booth PW, Schendel SA, Hausamen J-E, eds. Maxillofacial Surgery. Churchill Livingstone, Edinburgh: 1999, 877-88.

14. Palmisano BW, Rusy LM: Anesthesia for plastic surgery. In: Gregory GA, ed. Pediatric Anesthesia, 4th edition, Churchill Livingstone, New York: 2002, 707-45.

15. Posnick JC: Surgical management of Crouzon, Apert and related syndromes. In: Booth PW, Schendel SA, Hausamen J-E, eds. Maxillofacial Surgery. Churchill Livingstone, Edinburgh: 1999, 863-75.

16. Schindler E, Martini M, Messing-Junger M: Anesthesia for plastic and craniofacial surgery. In: Gregory GA, Andropoulos DB eds. Pediatric Anesthesia, 5th edition. Wiley-Blackwell, Oxford: 2012, 810-44.

17. Sticker PA, Shaw TL, DeSouza DG, et al: Blood loss, replacement and associated morbidity in infants and children undergoing craniofacial surgery. Pediatric Anesthesia 2010; 20(2):150-9.

18. Tessier P: Relationship of craniostenoses to craniofacial dysostoses and to faciostenoses: a study with therapeutic implications. Plast Reconstruct Surg 1971; 48(3):224-37.

19. Thomas K, Hughes C, Johnson D, et al: Anesthesia for surgery related to craniosynostosis: a review Part 1. Paediatr Anaesth 2012; doiL10.111/j/1460-9595.2012.03927.x

20. Thomas K, Hughes C, Johnson D, et al: Anesthesia for surgery related to craniosynostosis: a review Part 2. Paediatr Anaesth 2013; 23(1):22-7.

MAJOR SECONDARY CRANIOFACIAL SURGICAL PROCEDURES

SURGICAL CONSIDERATIONS

Description: These procedures usually are performed on children ≥ 5 yr. There are two basic approaches. The first involves advancement of the upper face and frontal bone, frequently described as a monobloc (Fig. 12.8-3) or frontofacial advancement. Occasionally, a LeFort III osteotomy and advancement may be performed depending on the anatomy. The second variation, called facial bipartition or periorbital osteotomy, is for correction of telorbitism (widely spaced eyes), usually accomplished by a combined extra- and intracranial approach, using both plastic and neurosurgery teams.

Variant procedure or approaches: Many different variations of the above-named procedures can be performed; however, from an anesthetic standpoint, they are not significantly different. The use of cranial bone grafts and rigid fixation have shortened these somewhat lengthy procedures. Other bone grafts, however, from ribs and iliac crest, are occasionally required. These procedures frequently last ≥ 6 h, and blood loss can be very heavy. Reconstruction of the forehead and orbital area following a tumor excision, for example, uses a similar approach but requires additional bone grafts. The use of external or internal distraction devices has eliminated the need for bone grafts and decreased associated complications such as infection.

Usual preop diagnosis: Craniofacial malformations; craniofacial deformities; telorbitism or hypertelorism; craniofacial dysostosis

Figure 12.8-3. Monobloc advancement. A: Lines of osteotomy for monobloc osteotomy. B: Advancement of midface, orbits, and frontal bone, and stabilization with bone grafts and miniplates. (Reproduced with permission from Aston SJ, Beasley RW, Thorne CH, eds: Grabb and Smith’s Plastic Surgery, 5th edition. Lippincott-Raven, Philadelphia: 1997.)

▪ SUMMARY OF PROCEDURES

	Monobloc/frontofacial Advancement	Facial Bipartition, Periorbital Osteotomies
Position	Supine	⇚
Incision	Bicoronal, oral	Bicoronal, infraorbital
Special instrumentation	Horseshoe headrest, usually pediatric; disimpaction forceps; Midas Rex craniotomy; resorbable plates and screws; mini/micro titanium plates and screws; ± distraction device to supplant bone grafting and rigid fixation.	⇚
Unique considerations	Control of ICP: spinal drain may be placed, hyperventilation. Blood in room for anticipated transfusion.	⇚
Antibiotics	Cefazolin 25 mg/kg q 8 h or vancomycin 10-15 mg/kg q 6 h, and cefotaxime 25-50 mg/kg q 6 h for oropharyngeal contamination and following dural tears	⇚
Surgical time	4-10 h	⇚
Closing considerations	Blood loss with Rainey clip removal for suturing. Full head-wrap dressing → head/neck movement with awakening.	⇚
EBL	400-800 mL; may be formidable	⇚
Postop care	ICU: 1-2 d; monitor Hct.	⇚
Mortality	0.6-1.6%	⇚
Morbidity	Major complications: 14.3% Bone infection: 3-7% Meningitis Infection rates higher if: Adults rather than children (10×) Longer OR times and longer hospital stay Tracheostomy Foreign body (plates/screws/other alloplast) Anterior fossa entered Large dead space (e.g., in adult nongrowing brain) CSF leak: 4.5% ↑ ICP Air embolus: < 1% Blindness: < 1% Massive bleeding: < 1% Venous thrombosis Neurological injury: Rare	⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚ ⇚
Pain score	6	6

ANESTHETIC CONSIDERATIONS

PREOPERATIVE

Craniofacial syndromes often are associated with maxillofacial deformities, mandibular abnormalities and challenging airway management.

Respiratory	Patients with long-standing upper airway obstruction due to choanal atresia, mandibular and maxillary hypoplasia, etc., may have chronic hypoventilation and hypoxia and may have apnea episodes. If Sx of acute URI, delay elective surgery at least 2 wk. The presence of fever, cough, and abnormal chest auscultation necessitates surgical cancellation and pediatric consultation. Tests: As indicated from H&P
Airway	Be aware of other congenital anomalies affecting the airway, such as Apert, Goldenhar, Klippel-Feil, Pierre Robin, Treacher Collins, or Crouzon syndromes. Review any previous anesthetic records for insights into airway management (e.g., need for Video laryngoscope or FOI). Consider elective tracheostomy under local anesthesia in patients with severe airway abnormalities.
Cardiovascular	Frequency of CHD is increased in patients with craniofacial abnormalities. Preop evaluation of patient with known or suspected heart defect should include H&P, ECG, Hct, baseline O₂ sat. For children with Sx of cardiac dysfunction or those requiring cardiac medication, it is advisable to consult with a pediatric cardiologist to optimize patient’s condition prior to surgery. Tests: Preop ECG, echocardiogram, CXR indicated for patients with CHD; others as indicated from H&P.
Neurological	Neurologic deficits, if any, should be documented preop.
Laboratory	Hb/Hct; therapeutic drug levels for patients taking anticonvulsants.
Premedication	Premedication is helpful for patients > 1 yr—oral midazolam 0.5-0.75 mg/kg or oral ketamine 6 mg/kg about 30-60 min before induction.
Pain	Pain management should be discussed preoperatively. Perioperative nerve blockade can be considered.