Unfavourable results in craniofacial surgery

Abstract

Craniofacial surgery is one of the newer subspecialties of plastic surgery and owes its birth to the pioneering work of Paul Tessier in the late sixties. Since then this challenging specialty work has been taken up by many centres around the word including India. Initial reports in late eighties and early nineties showed morbidity and mortality ranging from 1.6% to 4.3%. However over past few decades, with improved instrumentations, safer anaesthesia and cumulative experience of surgeons the morbidity and mortality has been brought down to as low as 0.1% in many centres in USA. In our centre at Post-graduate Institute, Chandigarh, the mortality rate is about 0.8% (4 out of 480 cases). The learning curve in this surgery is rather steep but with experience and a well-coordinated team work, results in this complex subspecialty can be improved. The infection is a major cause for worry but can be easily prevented by sound surgical principles and placing a vascularised tissue barrier between the extradural space and the nasopharynx/sinus mucosa.

INTRODUCTION

A man must be big enough to admit his mistakes, smart enough to profit from them, and strong enough to correct them………

John C. Maxwell

It is the highest form of self-respect to admit our errors and mistakes and make amends for them. To make a mistake is only an error in judgment, but to adhere to it when it is discovered shows infirmity of character…….

Dale Turner

The “surgeon” in us has always wished to have all operative interventions achieve the best outcome. One would desire to have a happy and satisfied patient at the end of the surgical journey. The unfavourable results and complications can be avoided by applying sound theoretical knowledge and acquiring the requisite skills. The surgical steps can be planned and rehearsed before the actual execution of the “live event”. All the surgeons develop “intuition” as they mature and gain experience over a period of time. This ability to differentiate between which case should or should not be operated is rather a slow acquisition. The golden rule to avoid unfavourable results is to follow the dictum “Primum non nocere.”

The complications are unintended events that may crepe in during the course of management and may or may not have any permanent deleterious effect on the patient. However unfavourable outcomes generally follow complications that neither the patient nor the surgeon likes.

Craniofacial surgery is the newer subspecialty of plastic surgery that has changed the lives of innumerable people and we owe its existence today to the pioneering work of Tessier.[1–3] It has now become an established discipline for management of anomalies of the craniofacial region that may be because of birth, trauma or malignancy. The craniofacial surgery has been defined as the “one in which there is circumferential stripping of the periorbita posteriorly up to the lateral margins of the superior orbital fissure in at least one orbit.”[4]

The craniofacial surgery is unique in the sense that it involves exploration of the areas that permit very little margin of error. An inadequate knowledge of the anatomy, lack of training and surgical expertise can lead to not only disastrous results but even to the death of the patient. This specialty demands a team work where all members have to work in perfect harmony in order to achieve the good results. Despite its many advantages, the craniofacial surgery carries a risk of major complications and even death.[5–8] The incidence of these complications has come down over the years because of better equipment, investigations, anaesthesia and cumulative surgical experience. In high volume units, including the ones in India, this “intimidating” surgery has now become quite safe with very low morbidity and mortality. The department of plastic surgery at Postgraduate Institute (PGI) Chandigarh has been undertaking these operations since 1995. A total of 480 transcranial cases have been performed till December 2012 in our unit. This article would discuss our experience along with review of the world literature.

SAFETY AND MORBIDITY STATUS OF CRANIOFACIAL SURGERY

Converse et al.[7] in 1975 reported mortality of 2% in 1975. Whitaker et al.[4] published the first major series showing combined experience of 6 major centres involving 793 patients in 1979 and observed mortality of 1.6% and morbidity of 16.5%. A study by Poole[6] showed mortality of 1.2%. The infection rate in this series was 4.4%. However, an experience from Turkey in 2000 showed mortality of 2.7% and complications of about 16.8%.[9] A recent study[10] in 2010 involving an experience of more than 8000 patients in major craniofacial centres in USA reported an overall morbidity and mortality of 0.1%. The mortality rate in our unit is about 0.8%.

Classification of unfavorable results

Whitaker et al.:[4] classified all the craniofacial surgeries into 3 groups:

• Intracranial (IC) operations with movement of one or more orbits (IC + O)

• Extracranial (EC) operations with movement of one or more orbits (EC + O)

• EC operations without movement of one or more orbits (EC).

We propose to categorise the unfavourable results in craniofacial surgery into 4 types:

Type 1

Minor mishaps that are correctable without any deleterious effects on the outcome of the patient and includes minor wound infections, poorly placed scars, scar alopecia, convulsions, minor cerebrospinal fluid (CSF) leaks and seromas/haematomas etc.

Type 2

Moderate to severe mishaps that lead to unfavourable results necessitating another surgical intervention for a successful outcome. The examples are exposure kerartitis, diplopia, contour deformities, exposed hardware etc.

Type 3

Moderately serious mishaps that would lead to some unfavourable result even if these have been managed successfully. These include nerve palsies, infection leading to bone loss and partial loss of vision.

Type 4

Serious mishaps that may even lead to death such as fulminant post-operative infection, perioperative bleeding, respiratory compromise or other serious anaesthesia related events.

The complications and unfavourable outcomes may happen because of events that could be related to anaesthesia, operative procedure or in the immediate or late post-operative period. It may be useful to deliberate upon these under the following heads.

ANESTHESIA RELATED

Difficult airway

The patients with craniofacial anomalies may have difficult airways, but an experienced anaesthetist is able to intubate almost every patient and there is hardly any need ever for tracheostomy. However in patients of skull base tumours wherein access is planned using maxillary swing osteotomy, we have found submental intubation to be of great help without adding any major morbidity.[11,12] In the majority of the patients, extubation can be done safely after the end of the surgery. We have routinely given a single induction dose of steroids at the end of surgery to avoid post-operative oedema of the respiratory tract following a prolonged surgery. The basis of this is anecdotal, but some studies have proved their beneficial effect in reducing post-operative facial oedema.[13,14] Some units secure the endotracheal tube with a wire to the teeth.

In the post-operative period, one must watch out for any respiratory distress that may develop as a result of unrecognized bleeding in the respiratory tract. When in doubt, the extubation may be delayed for 24 h or so.

Blood loss

Craniofacial surgeries involve major soft tissue and bony reconstructions that can result in major blood loss which may be significant enough in smaller children so as to qualify for almost whole body transfusion. Almost all the patients would require blood transfusion in craniofacial surgeries.[15–17] The blood loss can be minimized by tumescent infiltration of the incision sites and keeping the head end up. The flexion of the neck should be avoided as this may lead to venous engorgement. Use of bone wax, gelatin sponge, surgicel is quite helpful in reducing the blood loss. Sometimes if the blood loss is extensive, the procedure might have to be abandoned.[17]

Some authorities suggest the use of hypotensive anaesthesia, but others do not favour this approach as this may lead to neurological sequelae subsequent to reduced cerebral blood flow.[17]

The units in England use cell saver technology (autologous blood transfusion), especially relevant in Jehovahs witness patients.[18]

Hyponatremia and electrolyte imbalance

It has been suggested that a short term hyponatremia may result because of inappropriate secretion of antidiuretic hormone as a result of frontal lobe retraction.[6,15,19] However, some others feel that this could also result from cerebral salt wasting syndrome.[20] The treatment would therefore vary in these two conditions.

Venous air embolism

The position of head in most of the craniofacial cases is above the heart and so there is a risk of sucking in the air into the venous channels through open emissary/diploic veins or sinuses during craniotomy especially in small children. Meyer et al.[16] reported incidence of about 2.6% in patients undergoing craniosynostosis surgery. The insertion of central venous pressure line and monitoring of end tidal carbon dioxide helps diagnose the air embolism. Management includes cessation of surgery, lowering of head end, 100% oxygen inhalation and even open cardiac massage.[21]

Occuocardiac relex

There can be hypotension and bradycardia because of globe manipulation during transcranial surgery.[6] Jones et al.[15] reported two cases of severe occulocardiac reflex during periorbital dissection necessitating adrenaline administration.

INTRAOPERATIVE

Incision related

Scar Alpoecia can result if there is damage to the hair follicles during the flap elevation The introduction of trichophytic closure techniques in which the hair that grow through the scar have helped avoid this complication.[22] One side of the existing skin is cut at an oblique angle, after which the adjacent skin flaps are brought together to close the wound. One piece of scalp tissue now lies underneath another one and in it also hair follicles, which then slowly grow through the tissue and the future scar line is then covered with hair [Figure 1].

Figure 1.

Technique of trichophytic closure. One edge of the incision has been cut obliquely before closure (*)

The incision can be made into a wavy pattern as the zigzag scars are aesthetically better than a straight line scars.

The frontal branch can get injured while raising the coronal flap. This can be very easily avoided if dissection is kept in the proper planes. Kerawala et al.[23] reported incidence of 22% of frontalis weakness that recovered in all their patients. They have also reported sensory disturbance immediately after surgery in 35% patients, but it recovered completely in all the patients by 2 years.

Eyelid retraction can result if all the layers of the tissue in a subciliary incision are divided at the same level. A step design may be introduced at various levels.

Flaring of nostrils can result following gingivobuccal incision taken for the le fort 1 osteotomy it is important to suture dis-inserted muscles at the alar base on either side by taking an alar cinch stitch. Failure to do so would result in alar flattening and drooping of the alar tip [Figure 2]. It is also important to close mucosal incision in a v-y fashion near the midline in order to have adequate pout of the upper lip.

Figure 2.

Alar cinch stitch with a non-absorbable material to avoid flaring of the alae

Temporal hollowness can result if the temporalis muscle is not sutured back to its attachments to the lateral orbital wall. It needs to be anchored by non-absorbable suture. One may need to create drill holes in the bone for suturing or the suture may be anchored to a plate adjacent area.

Realted to frontogaleal flap

The frontogalael flap has been recommended for prevention of ascending infection from the adjacent nasopharynx or sinuses.[24] However, elevation of this flap results in thinning of the skin and may result in pressure necrosis of the skin cover in the forehead region. This is more applicable in small children.[25] [Figure 3]. It is important not to apply any pressure dressing over the forehead region in such cases.

Figure 3.

Pressure ischemia over the forehead region from where the fronto-galeal flap has been harvested (upper row). Well healed flaps after the pressure was relived (lower row)

If frontogaleal flap is harvested from one side only it may lead to asymmetry of the eyebrows. This can be easily avoided if frontogaleal flap is harvested from both sides.

In redo surgeries, the skin flaps may be adherent because of the previous operation and may break down in the post-operative period this may settle down by conservative treatment [Figure 4] or may even require local flaps to resurface the exposed bones [Figure 5].

Figure 4.

Ischemia of the flap after re-do surgery (upper row) that settled down with dressings only

Figure 5.

A case of nasal encephalocele with exposed bones in the post-operative period (upper row). It required local flaps for wound closure (lower row)

Contour irregularity of the underlying bones may become more apparent once the skin becomes thin after the harvest of the flap. And this may need some kind of camouflage by fat grafting in that region.

Related to bony osteotomies

Unequal movement of fronto-orbital segments: This is likely to happen if care is not taken during the time of fixation of segments and can be very difficult to correct later. Hence utmost care must be exercised during plate fixation.

Large bony defects: The cranioplasty and advancement procedure done for craniosynostosis leave some bony gaps that usually get ossified adequately in small children but may not happen so in older children. These might need to be addressed by using autogenous bone grafting later.

Burr hole contour deformity

Previously multiple burr wholes were made for craniotomies and these would leave contour deformities that needed to be managed later with small bone grafts [Figure 6]. These deformities have become rare with the availability of power perforators and drills being used for craniotomies now days.

Figure 6.

Craniotomy burr hole defects presenting as contour defect (upper row). These were managed with a small split cranial bone grafts (lower row)

Sliding bone flaps

This is seen if osteoplastic flaps containing bone and temporalis muscle has been lifted in the temporal region and has been repositioned back without rigid fixation. The constant pull of temporalis muscle keeps dragging the unstable bone flap inferiorly leading to bony gap near the vertex. The management requires re-fixation of the bony segment with plates and screws.[26] [Figure 7] shows an example where bony fixation and additional bone graft were required for correction of the defect and the contour deformity.

Figure 7.

Sliding bone flap after improperly fixed osteoplastic flap (upper row). This required fixation with plates and screws and additional bone grafts (lower row)

Malocclusion may develop following facial bipartition procedures or during Le fort 1 osteotomy. These can be avoided if proper position of jaws is ascertained during plate fixation.

Necrosis of part of the palate in cases of maxillary swing Lle fort 1 osteotomy may happen if the blood supply gets compromised either because of damage to the main vessels or because of extensive periosteal stripping.

Miscellaneous

Minor Palatal fistula may result in cases of facial bipartition or maxillary swing procedures and generally heal by themselves if the gap is very small. Larger fistulas may need some kind of flap transposition for closure later.

Inadvertent dural tears may occur and can go unnoticed during surgery. Various authors have reported incidence of 5-60%.[6,27,28] This may result in CSF leaks into the drain or wound. Theses tend to settle down with conservative management by lumbar drainage and discontinuation of negative suction drainage to the wound. Innovations like drainage of the wound CSF with intravenous canula has also been reported in cases where lumbar drainage may not be possible[29] [Figure 8].

Figure 8.

Persistent cerebrospinal fluid leak from the wound in a patient (upper row left) managed successfully (upper row left) with the help of an intracath placed inside the wound (lower row). The lumbar drainage was unsuccessful in this child

Rarely a minor overlooked dural tear can lead to the development of pseudoencephalocele.[30] We also had a similar case where 2 years after the initial repair, the patient developed a swelling in the frontal region. This was bulging brain through a small gap in the dura and pushing the bony segments to create a gap. The dural repair was done using fascia lata and the bone gap was corrected using split cranial bone graft [Figure 9].

Figure 9.

Upper row: A child of encephalocele presented 2 years after correction with a pseudomeningocoel in frontal region. This was reduced, a fasica lata duraplasty done and split cranial bone cranioplasty performed (lower row)

Extradural hematoma are very rare in craniofacial surgery operations Early recognition is very important. This needs urgent re- exploration and evacuation. Poole[6] noted only one case of extradural hematoma in 168 cases. We have also noted one case out of 480 transcranial cases.

Harvesting of cranial bone is a very safe procedure and the complication rate is almost negligible. Fearon[31] concluded that “not only is in situ cranial bone graft harvest a safe procedure as assessed by clinical outcomes, but no subclinical complications were identified by post-operative magnetic resonance imaging” In a large series of 568 patients Kline and Wolfe[32] noted a complication rate of 1% in cranial bone harvest whereas the same authors found a complication rate of 5-30% in patients undergoing rib or iliac bone graft. Similar experience was noted in a large series of 20,000 patients by Tessier et al.[33] We have also not encountered any significant morbidity in our unit with the extensive use of split cranial graft.

Bone wax granuloma

The bone wax is used for controlling bleeding from the diploe after harvesting the split cranial bone graft or at the craniofacial osteotomy sites. Cases of bone wax granuloma have been reported in literature[34] The bone wax granuloma presents as a persistent sinus. The treatment is the removal of the bone wax [Figure 10].

Figure 10.

A cranioplasty defect that has been managed with split cranial bone graft from the other side (upper row). In the post-operative period child had a persistent sinus that on exploration was found to be bone wax grauloma at the bone graft donor site (lower row)

Related to hardware

The plates are used for fixation of the bony segments. The palpability is fairly common, but the exposure and infection is rare.[35,36] The palpable metal hardware may be removed if it causes pain and irritability. In a study by Orringer et al.[37] concluded that common reasons for hardware removal included palpable/prominent hardware in 34.5%, loosening of plates and screws in 25.5%, pain in 25.5%, infection in 23.6%, wound dehiscence/exposure of hardware in 20%, and removal at the time of secondary procedures 9.1%.

Another concern of the metal fixation is IC migration of the hardware because of appositional growth of the calvarial bones.[38] However, studies have shown no adverse effect of this phenomenon.[39] The use of absorbable plates have now taken care of this concern.[40–42]

The plates might get exposed if the overlying skin envelop is tight; this might happen in situations where the skin lies collapsed because of bone loss such as in large cranial vault defects [Figure 11].

Figure 11.

A large cranioplasty defect of 4 years duration reconstructed with split cranial bone graft (upper row). The skin envelop was tight and resulted in the breakdown of skin. This was managed with an urgent free tissue transfer (lower row)

Calcium hydroxyapatite, titanium meshes, custom made bone scaffolds and bone cement are commonly used for cranioplasties. There is a significant risk of complications with alloplastic material as compared to autologous bone.[33]

Periorbital/eye related

Blindness/partial vision loss

Blindness is rare but a real danger and can happen in cases where extensive periorbital stripping especially in cases of box osteotomy is performed for hypertelorism cases. An utmost care must be taken that there is no traction on the optic nerve. One must be very careful of using power tools especially the high speed drill/burr in the vicinity of the optic foramen. We have seen one case of partial loss of vision in a case of fibrous dysplasia where the optic nerve decompression was being done. Munro and Sabatier[43] has reported four cases of blindness in 1098 craniofacial patients.

Corneal shields used intra-operative prevent any corneal damage. Frost tarsorraphy sutures can help in the early post-operative recovery phase.

There might be transient diplopia and conjunctival chemosis which settles down with conservative management. Utmost care must be taken to avoid any injury to the cornea during surgery. A temporary tarsoraphy may be a very useful adjunct.

Temporary ptosis [Figure 12] and strabismus [Figure 13 left] is commonly seen in cases involving periorbital dissection. This is self-limiting and gets corrected over the next couple of months. It has been seen that strabismus–might co- exist pre-operatively in many cases especially unicoronal synostosis and hypertelorism.[6,42] It has been recommended to wait for at least 6 months before corrective surgery for either strabismus or ptosis is undertaken.

Figure 12.

A case of intra-conal/extra-conal orbital vascular malformation per-operative (upper row) 2 month post-operative showing ptosis on the affected side (lower row). This took 6 months to recover completely

Figure 13.

Strabismus (left side) and orbital dystopia and anti-mongoloid slant in a patient (right side)

Antimogoloid slant [Figure 13 right] can develop if care is not taken to fix the lateral canthus at the end of the fronto-orbital advancement surgery especially in syndromic cases.[43]

Lacrimal drainage problems can also be seen in patients with hypertelorism where box osteotomy has been done. However, the incidence is about 0.7% only and is generally self-limiting.[44] If epiphora persists dacrocystorhinostomy drainage procedure can be done.

Infection

Infection is the commonest and most dreaded complication of craniofacial surgery and the incidence have been reported to be about 6% in transcranial cases.[45] The risk factors that predispose to the infection are opening of the nasal or sinus mucosa at the time of surgery. The infection can easily travel up the extradural space IC. It has been observed that completely repairing the mucosal breach and separation of the nasal/sinus mucosa by using vascularised frontogaleal flaps can reduce the chances of infection in such cases.[22] Salyer[46] and Murray et al.[47] have concluded that the chances of infection in infants and younger children are less than in adults as the brain expands rapidly to obliterate any extradural dead space that may develop in transcranial surgeries. At PGI Chandigarh, the minor infection rates have been less than 4% and there was only one major morbidity due to infection out of 480 transcranial cases. Here, the fronto-orbital segment after the advancement in an Apert's patient had to be removed because of fulminant sepsis. The reconstruction was attempted 6 months after the healing had taken place [Figure 14].

Figure 14.

A case of Apert's syndrome who had fulminant infection post-operatively leading to loss of skin and fronto-orbital segment (upper row). The skin defect was resurfaced with a small free flap and the missing bony segment was reconstructed using autogenous rib and calvarial bone (lower row)

The infection may present as fever, meningitis or sometimes as osteomyelitis. If the bone gets infected, it needs to be debrided.

Neurological deficit

Since most of the transcranial surgeries are extradural, the chances of any permanent neurological deficit are very remote.[6,15,19]

Death

The earlier series reported mortality ranging from 1.6% to 4.3%.[4,5,7] However, with better equipment, safer anaesthesia and cumulative experience this figure has come down steadily to about 0.1% in large craniofacial centres in the USA. The mortality at PGI has been four deaths out of 480 transcranial procedures in the last 17 years (0.8%). Majority of these happened in syndromic children and happened either because of excessive bleeding on the table or in the immediate post-operative period. One adult syndromic patient died 5^th post-operative day because of unexplained deteriorating neurological status.

CONCLUSIONS

The craniofacial surgery is very challenging and delicate exercise that requires a well-coordinated team work. There is potential for major complications and even mortality. However over the last few decades many centres around the world have shown that the results can be improved and complications can be minimized by careful planning and execution of the surgical techniques. Almost all the major series have shown higher complications in the earlier phase of starting such surgeries. As the experience is gained, the surgical execution becomes quicker and the complications related to either the surgery or the anaesthesia get reduced considerably.