Journal of Neurosurgery - 109(1):1

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July 2008 Volume 109, Number = 1

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Craniopharyngiomas

Paolo=20 Cappabianca, M.D., Luigi M.=20 Cavallo, M.D., Ph.D., Felice=20 Esposito, M.D., Ph.D., and Enrico De Divitiis, = M.D.

Department of=20 Neurosurgery, Universit=E0 degli Studi di Napoli = Federico II,=20 Naples, Italy

DOI: = 10.3171/JNS/2008/109/7/0001a

Editorial	ReferencesResponseReferences

=93Craniopharyngiomas: transsphenoidal method of = approach=97for=20 the virtuoso only?=94 is the title of the Ciric and=20 Cozzens'² = presentation at the Congress of Neurological Surgeons = meeting=20 in Las Vegas, Nevada, in 1979. This question does not = seem=20 true but rather rhetorical, which is confirmed by the = reasons=20 reported by the authors. Coming almost 30 years later, = the=20 article by Gardner et al.=97while observing the = evolution of the=20 technique, which is not limited as before to sellar = lesions=20 with suprasellar extension (preferably = infradiaphragmatic or=20 cystic), but is targeted to the suprasellar = ones=97raises=20 further questions and at the same time reinforces the=20 provocation of Ciric and Cozzens. As a matter of fact = there=20 are few brain lesions with such a multiform aspect and = an=20 unpredictable biological behavior as = craniopharyngiomas, whose=20 optimal treatment is controversial. If it is true that = the=20 radical surgical approach is the only therapeutic = option to=20 ensure a long-term control of the disease, it is also = true=20 that the price to pay for the radicality at all costs = is=20 sometimes very high in terms of functional outcomes, = which may=20 help explain why many different surgical approaches = have been=20 used for the purpose and the alternatives to the = classic=20 surgical indications, especially in cases of = children.

In most cases, craniopharyngiomas are tumors = located in the=20 midline skull base. There are no other surgical = approaches=20 other than the extended transsphenoidal approach that = offer=20 the advantage to visualize the tumor just after the = dural=20 opening without brain retraction. No other approach = provides a=20 good and close visualization of the relevant anatomy, = a direct=20 trajectory, and a wide window. The transsphenoidal = approach is=20 even more attractive when the surgeon is dealing with = a=20 recurrence, which is quite common in these lesions, = and the=20 tumor can be controlled from a different perspective, = thus=20 avoiding new brain manipulation. Over the last decade=20 tremendous efforts have been made to overcome some of = the=20 major problems that have provoked criticisms to such a = technique, namely better-quality endoscopic images and = new=20 surgical instruments and tools to render the overall = procedure=20 safer and more effective.

Our experience³ = is in=20 agreement with the report of Gardner et al. They point = out the=20 crucial role of the endoscope in the transsphenoidal=20 management of suprasellar skull base lesions in that = there are=20 no limitations created by the transsphenoidal = speculum. Even=20 more central is the importance they attribute to the = perfect=20 knowledge of the once-unfamiliar anatomy of the = approach and=20 the relevance of the team strategy to add competences = to open=20 and go along well new surgical tasks.

Gardner and associates describe 16 adult patients = harboring=20 craniopharyngiomas located above the sella, superior = and=20 posterior to the chiasm and even in the third = ventricle. Six=20 of these patients had previously undergone surgery or=20 radiosurgery, which is in line with similar = reports.^3,5 = Some=20 aspects need to be highlighted. Near-total resection = was=20 attained in 12 (75%) of the 16 patients, which is a = good=20 result. The quality of life after surgery was good in = all but=20 1 patient, who suffered a posterior cerebellar artery = infarct.=20 There was no worsening in the patients' = ophthalmological=20 conditions after surgery, and in fact almost all = improved. All=20 patients experienced excellent results in anterior = pituitary=20 function, which is not surprising given that the = approach=20 follows a supraglandular route. One patient suffered = permanent=20 DI and 4 suffered temporary DI, which seems like a = good=20 outcome, but it should be considered that the stalk = was=20 preserved also in infundibular craniopharyngiomas, = which can=20 expose to recurrence. Four patients with Type II = tumors=20 experienced recurrence or regrowth without stalk = sacrifice. No=20 patient died as a result of surgery, and there were no = cases=20 of bacterial meningitis. The vascular injury rate was = 5%,=20 which seems a good outcome. The major complication was = cerebrospinal fluid (CSF) leakage. Over the course of = their=20 study, the CSF leakage rate decreased from 70% to 20% = in the=20 more recently treated cases.

Currently, a major problem that might limit the = procedure=20 is the high rate of postoperative CSF leakage, and no=20 radically effective solution has been found yet. In = the effort=20 to lower such a rate, we have followed some of the = indications=20 proposed by the Pittsburgh group, like the use of the = Foley=20 balloon to hold the reconstruction material(s) in = place and,=20 more recently, the nasoseptal mucosal flap.⁶ = At the=20 moment we have adopted the use of the nasoseptal flap = in 12=20 patients who underwent an extended transsphenoidal = approach=20 for suprasellar lesions. In this cohort we experienced = 5 cases=20 of CSF leakage, 3 of which were intraventricular=20 craniopharyngiomas. If we analyze our present series = of 17=20 patients with craniopharyngiomas who underwent surgery = via an=20 extended transsphenoidal approach, we have experienced = 5 cases=20 of CSF leakage, 4 of which were intraventricular=20 craniopharyngiomas. Three of these were reconstructed = with the=20 nasoseptal flap. These patients with intraventricular=20 craniopharyngiomas are a very challenging subgroup. = They=20 present with a direct communication of the third = ventricle=20 with the nasal cavities, and they must undergo a wide=20 arachnoid dissection. However, the postoperative CSF = leakage=20 rate reaches unacceptable percentages, and the = expectancies of=20 the nasoseptal flap seem to have failed their promises = in=20 these circumstances. In our opinion¹ = it means=20 that the reconstruction strategy is not yet fit to the = purpose=20 and that the solutions proposed (that is, multilayered = planes,=20 vascularized flap, and so on) are not completely = adequate to=20 the goal; none has been shown to reduce the rate of=20 postoperative CSF leakage to an acceptable level (< = 1%), as=20 it currently is for the =93standard=94 transsphenoidal = pituitary=20 surgery.

Nevertheless, as reported in some of our recent=20 contributions^3,4 = the=20 extended transsphenoidal approaches offer undoubtable=20 advantages in better visualization of the = subchiasmatic and/or=20 intraventricular area, where several suprasellar=20 craniopharyngiomas arise and/or extend, when compared = with the=20 transcranial operations. Another advantage of the = low-route=20 approach is that the procedure can be performed = regardless of=20 the position of the chiasm and the sometimes low = position of=20 the anterior communicating artery complex, which may = lead to a=20 very difficult tumor resection in all types of basal=20 transcranial approaches. When performing the = dissection under=20 direct visual control, the extended transsphenoidal = route=20 permits surgeons to reach from below the various types = of=20 craniopharyngiomas. Using the same surgical corridor, = but=20 depending on the site of the lesion, the surgeon can = work=20 either below or above the optic chiasm with minimal = optic=20 apparatus manipulation and through both sides of the = stalk,=20 thus managing both the suprasellar prechiasmatic and = the=20 intraventricular craniopharyngiomas. The trajectory = afforded=20 by the transsphenoidal approach permits the = neurosurgeon to=20 work along the same axis of the path of this type of=20 craniopharyngioma. In such a way, also the purely = suprasellar=20 intraventricular masses, which are associated with a = small or=20 normal-sized sella and are traditionally considered = unsuitable=20 for the transsphenoidal route, can be successfully = removed=20 with this technique.

Nevertheless, not every patient with a = craniopharyngioma is=20 a good candidate for such an extended approach. The = degree of=20 pneumatization of the sphenoid sinus plays a major = role. A=20 presellar- or conchal-type sinus represents a relative = contraindication to an extended approach because the = main=20 landmarks within the sphenoid sinus are not well = recognizable,=20 thus increasing the risk of injury to the = intracavernous=20 internal carotid arteries and the optic nerves. A high = dorsum=20 can render the procedure more difficult, especially in = the=20 case of retrosellar extension of the lesion. The = anterior=20 intercavernous sinus can influence the bone resection = given=20 that it can bleed profusely. The consistency, blood = supply,=20 and adherence to the surrounding neurovascular = structures by=20 the tumor can represent an obstacle for the approach. = In=20 addition, the narrow space for the instruments might = create=20 problems in cases of hemorrhage, given that control of = the=20 bleeding is mandatory to work in a clean surgical = field. Other=20 limitations should not be underestimated, such as the=20 following: 1) the need for an incremental acquisition = of=20 skills before becoming confident with the peculiar = anatomy and=20 the manipulation of all structures, as seen from = below; 2) the=20 necessity for dedicated instruments, all of which as = yet are=20 not available; and 3) lack of initial skill, which = makes the=20 operative times longer. The time required for an = extended=20 approach in our experience is still superior to that = needed=20 using a transcranial approach.

Returning to the title question of Ciric and = Cozzens,=20 extended transsphenoidal surgery should be left in = expert=20 surgeons' hands. Perfect knowledge of anatomy, fine = technical=20 skill, talent, and a strategic team approach are = required;=20 Gardner et al. have shown these qualities. However, = these are=20 not enough to put the words =93the end=94 to the whole = story.=20 Surgeons must decide the appropriate balance between = the=20 reality of the situation and the rules. A sense of = measure is=20 needed to read and to join the flaming beauty of the = reality=20 with the cold severity of the rules. The rules = concerning many=20 aspects of the procedure need some more work and = solutions=20 need to be defined, as well as the development and = improvement=20 of the specific instruments for the procedure and the = ideal=20 technique of reconstruction of the approach. Then it = will be=20 necessary, as Gardner and colleagues affirm, to = analyze larger=20 series and longer follow-up, and the appropriate = indications=20 for this rather than other surgical solutions can be = defined.=20 In the meantime there will be those who will be = playing the=20 role to push the frontiers and others who will move in = subsequent advancements, trying to be at the same time = in the=20 game and in the posse, which is not always easy or = even=20 possible. Nonetheless, surgeons are eager to know the = cure=20 rate of tumors in patients who undergo such an = approach, the=20 effectiveness of this procedure, and the indications = to use it=20 instead of other approaches, which are not yet = possible to=20 define.

We need to keep working hard, to = participate in=20 the ongoing international scientific debate without=20 preconceived ideas, and to study and understand our = efforts to=20 validate them. Craniopharyngiomas are very challenging = lesions, and sometimes it is the lesion and not the = surgeon=20 that decides the destiny of the patient. So the task = is to try=20 to understand in advance which is and will be the best = proposal for the individual with a=20 craniopharyngioma.

References	EditorialReferences <<References

1.	Cavallo LM, Messina A,=20 = Esposito=20 F, de=20 Divitiis O, Dal Fabbro = M,=20 = de=20 Divitiis E, et=20 al.: Skull base reconstruction in the extended=20 endoscopic transsphenoidal approach for = suprasellar=20 lesions. J = Neurosurg 107:713=96720, 2007 [Abstract]
2.	Ciric IS, Cozzens JW:=20 =20 Craniopharyngiomas: transsphenoidal method of=20 approach=97for the virtuoso only?. Clin = Neurosurg=20 27:169=96187, 1980
3.	de Divitiis E, Cappabianca = P,=20 = Cavallo=20 LM, =20 Esposito F, de Divitiis = O,=20 = Messina=20 A: = Extended=20 endoscopic transsphenoidal approach for = extrasellar=20 craniopharyngiomas. Neurosurgery 61:5=20 Suppl219=96228, 2007
4.	de Divitiis E, Cavallo LM,=20 = Cappabianca P, Esposito F:=20 = Extended=20 endoscopic endonasal transsphenoidal approach = for the=20 removal of suprasellar tumors: part 2. Neurosurgery=20 60:46=9659, 2007
5.	Frank G, Pasquini E,=20 = Doglietto=20 F, =20 Mazzatenta D, Sciarretta = V,=20 = Farneti=20 G, et = al.: The=20 endoscopic extended transsphenoidal approach for = craniopharyngiomas. Neurosurgery 59:1=20 Suppl 1ONS75=96ONS83, 2006
6.	Hadad G, = Bassagasteguy L,=20 = Carrau=20 RL, =20 Mataza JC, Kassam A, = Snyderman = CH,=20 et = al.: A novel=20 reconstructive technique after endoscopic = expanded=20 endonasal approaches: vascular pedicle = nasoseptal flap.=20 Laryngoscope=20 116:1882=961886, 2006

Response	EditorialReferencesReferences

At the onset we are very grateful for the comments = provided=20 by both Drs. Rutka and Cappabianca. We would like to = address=20 each separately.

With respect to Dr. Rutka's comments, we found them = to be=20 thoughtful and insightful as they addressed the key = issues=20 related to the management of craniopharyngiomas = through the=20 EEA. Important considerations are raised relative to = the=20 practical value of the classification proposed in this = study.=20 We do agree that it can be difficult to preoperatively = distinguish the craniopharyngioma subtype based on MR = imaging=20 findings. Having said that, using high resolution,=20 thin-section, axial MR images we found this to be a = problem in=20 a minority of cases. Starting at the level of the = third=20 ventricle from a rostral to caudal direction with the = aid of=20 axial images, one can usually identify the stalk's = origin and=20 follow it down to the sella, noting the greater part = of the=20 tumor's position relative to the stalk. In = invaginating=20 lesions that engulf the region of the suprasellar = cistern this=20 may not be possible, and the only way to classify the = lesion=20 with certainty may be at the time of surgery. = Therefore, in=20 practice, we propose this classification not = necessarily=20 exclusively for preoperative planning, but also for=20 intraoperative management, as we have found it = extremely=20 useful at the time of surgery. The information gleaned = from=20 the preoperative MR images can then be augmented with = the=20 unique visualization provided endoscopically, = particularly=20 with the advent of new high-definition optics, to = better=20 delineate the subtype of craniopharyngioma. Given the = fact=20 that the surgical technique is modular, this allows = for=20 strategic modifications at the time of surgery. For = example,=20 if the lesion is believed to be retroinfundibular=20 preoperatively, and this is verified intraoperatively, = then=20 the additional module of a pituitary transposition = with=20 posterior clinoidectomies and dorsectomy can be = added.⁶ = We believe=20 the classification's value is to provide a conceptual=20 framework that provides a surgical approach algorithm. = Specifically, in the case of retroinfundibular lesions = posterior to the Liliequist membrane, rather than = trying to=20 gain access through the suprasellar cistern and = risking injury=20 to vasculature that may be adherent to the tumor's = posterior=20 wall, a pituitary transposition will allow direct = access to=20 the posterior circulation providing for controlled = dissection=20 through a relatively much larger working = window.⁶ = We would=20 like to clarify that we are not suggesting that the=20 classification be applied exclusively based on = preoperative=20 imaging and in fact suggest that it is only at the = time of=20 surgery that preoperative perceptions can be = confirmed. We=20 thank Dr. Rutka for pointing this out.

Next, Dr. Rutka raises the critical issue of = long-term data=20 collection and neuropsychological outcome. This part = cuts to=20 the heart of craniopharyngioma management. Our study = is flawed=20 by the lack of long-term data as well as = neuropsychological=20 outcomes. We provide the study only as a proof of = concept and=20 look forward to capturing these data to determine if, = in fact,=20 there is true value to our approach. Toward this end, = a=20 separate prospective study has been undertaken looking = at pre-=20 and postoperative neurocognitive function. Preliminary = results=20 at this stage seem encouraging and appear to confirm = Dr.=20 Rutka's impression that EEA will have significant = benefit.

We are most grateful for Dr. Rutka's thoughtful = comments=20 and concur with him on every aspect of his review. Two = additional questions that were raised, that is, the=20 applicability in pediatric patients and recurrent = disease, are=20 discussed later.

With respect to the review and comments made by = Professor=20 Cappabianca et al., we would like to address them=20 systematically. To allow for adequate follow-up, the = last=20 patient included in this series underwent surgery in = February=20 2006. Since that time, an additional 18 patients have=20 undergone EEA for resection of craniopharyngiomas at = the=20 University of Pittsburgh Medical Center. In an effort = to=20 address some of the concerns raised by the review from = Dr.=20 Cappabianca et al., as well as the comments based on = their own=20 personal series of 17 patients, we provide an update = on our=20 entire cohort of 34 patients (16 patients reported = originally=20 and 18 subsequently). The group of 18 additional = patients (10=20 males and 8 females) with craniopharyngioma had a mean = age of=20 41.1 years. Five of the 18 patients were children, the = youngest being 9 years.

We agree with these reviewers' comments on the = advantages=20 of accessing a midline lesion through a midline = corridor. We=20 respectfully disagree, however, with the proposed = limitations=20 offered. Cappabianca et al. mention the degree of=20 pneumatization, presellar/conchal-type sinus, and a = high=20 dorsum sella (for retroinfundibular lesions) as = relative=20 contraindications to the endonasal route. Although we = believe=20 that these represent challenges, it is precisely in = this=20 setting that the classification is useful. For = example, in the=20 case of high dorsums, the modular approaches with = pituitary=20 transposition allow for direct retrodorsal lesion = access with=20 immediate isolation and control of the posterior=20 circulation.⁶ = This=20 obviates the limitation of working in a small dark = hole as=20 these authors point out when one approaches = retrodorsal=20 lesions through a purely suprasellar corridor. With = regard to=20 degree of pneumatization, we have not found this = prohibitive=20 in any case. Understanding of key anatomical = landmarks, such=20 as the vidian nerve⁸ = and the=20 medial clinoid,⁷ = overcome=20 these issues. These latter issues are especially = germane in=20 pediatric patients. We have performed EEAs for diverse = pathological entities in patients as young as 3 years = of=20 age.^7,9 = In the=20 updated craniopharyngioma series discussed earlier, we = have=20 been able to undertake EEA for craniopharyngiomas in a = child 9=20 years of age.

The next issue raised by Cappabianca et al. focuses = on the=20 management of CSF reconstruction. Although we agree = completely=20 with the authors' perspective on the need to reduce = this=20 complication to an acceptable level, we also believe = that=20 there are several important points that need to be = considered.=20 Early in our series we experienced an exceptionally = high rate=20 of CSF leakage (70%); however, the overall rates of = other=20 outcomes (vision, endocrine, and so on) were very = encouraging=20 (as reported in this paper). The incidence of vascular = complication was 6% (1 of 16) in the original series = and 3% (1=20 of 34) in the updated series. Based on these findings = and the=20 fact that we did not see a significant incidence of=20 meningitis, we were encouraged to continue with the = endonasal=20 route while seeking improved reconstruction = solutions.⁴ = We believe=20 the development of the nasoseptal flap has, in fact, = been a=20 significant evolution in this effort.^3,5=20 Cappabianca et al. report a relatively high failure = rate with=20 the use of this flap in their early experience, = particularly=20 in this population of craniopharyngiomas, and they = attribute=20 this failure to the pathology and degree of anatomical = dissection (that is, wide arachnoidal cisternal = opening and=20 ventricular communications). We have previously = identified=20 these as critical factors impacting = reconstruction.⁴ = At the=20 time of publication of our original series of 16 = patients, we=20 were just gaining experience with the vascularized = nasoseptal=20 flap.³ = In the=20 subsequent 18 patients in the updated series who were=20 consistently reconstructed using the nasoseptal flap,=20 postoperative CSF leakage occurred in only 1 patient.=20 Therefore, the CSF leakage rate has been reduced to = 5.56%,=20 which is at least comparable to multiple series of = open=20 approaches for anterior fossa pathologies.^1,2 = We again=20 respectfully disagree with the statement from = Cappabianca et=20 al. that the CSF leak must be reduced to < 1% when=20 resecting craniopharyngiomas through this route. The=20 comparisons between pituitary surgery and = craniopharyngioma=20 surgery are not valid by virtue of the fact that (as=20 Cappabianca et al. have stated) wide arachnoidal = cisternal=20 opening and ventricular communications are = prerequisites in=20 the latter compared with the former. A leakage rate of = 5% is=20 consistent with that noted after many skull base = approaches=20 used for transcranial craniopharyngioma surgery.

In terms of these reviewers' statement that =93the=20 expectancies of the nasoseptal flap seem to have = failed their=20 promises=94 we would like to clarify that we have made = no=20 promises but simply offered an alternative for = vascular=20 reconstruction. There are many groups currently using = the flap=20 successfully. There are critical nuances that are = inherent in=20 raising the flap and we leave this portion of the = procedure to=20 the otolaryngologist who is more familiar with the = regional=20 anatomy, the contents of the pterygomaxillary fissure, = and the=20 distal branches of the internal maxillary artery that = form the=20 pedicle. In our institution, these flaps are raised by = an=20 experienced otolaryngologist in each case. This is = precisely=20 why we pursue a team approach (otolaryngologist and=20 neurosurgeon). In addition, there is clearly a = learning curve=20 associated in raising these flaps as our results have = improved=20 over time.⁵

We completely agree with both Professors Rutka and=20 Cappabianca et al. that the goals of surgery need to = be=20 tempered to ensure optimum outcomes. There are = additional=20 tools available to the surgeon in the management of = this=20 disease, including radiation therapy and reoperation. = The=20 ideal surgical approach should be one that minimizes = morbid=20 outcomes, optimizes function, and does not preclude=20 reoperation when needed. We have found EEA well suited = for=20 reoperation when required whether the patient has had = previous=20 surgery and/or radiation. As demonstrated in this = series, none=20 of the recurrences that required repeated EEA suffered = a new=20 complication.

Finally, we agree with Cappabianca et = al. that=20 this is =93not the end of the story.=94 We have never = suggested=20 that EEA is a curative procedure for = craniopharyngiomas or=20 that it represents the only viable option. In fact, in = our=20 classification scheme we present 4 categories of=20 craniopharyngiomas. The first 3 can be addressed by = EEA,=20 whereas Type IV in our opinion is best treated via a=20 transcranial route. We offer this midline corridor to = simply=20 augment the surgeon's armamentarium.

Amin=20 B. Kassam, M.D., Daniel M. Prevedello, M.D., = and=20 Paul A. Gardner, = M.D.

University of Pittsburgh Medical = Center,=20 Pittsburgh, Pennsylvania

References	EditorialReferencesResponse

1.	Deschler DG, Gutin PH, = Mamelak AN,=20 = McDermott=20 MW, =20 Kaplan MJ: =20 Complications of anterior skull base surgery. = Skull Base = Surg=20 6:113=96118, 1996
2.	Feiz-Erfan I, Han PP, = Spetzler RF, = = Horn EM,=20 = Klopfenstein JD, Porter RW,=20 et = al.: The=20 radical transbasal approach for resection of = anterior=20 and midline skull base lesions. J = Neurosurg=20 103:485=96490, 2005
3.	Hadad G, = Bassagasteguy L,=20 = Carrau=20 RL, =20 Mataza JC, Kassam A, = Snyderman = CH,=20 et = al.: A novel=20 reconstructive technique after endoscopic = expanded=20 endonasal approaches: vascular pedicle = nasoseptal flap.=20 Laryngoscope=20 116:1882=961886, 2006
4.	Kassam A, Carrau RL,=20 = Snyderman=20 CH, =20 Gardner P, Mintz A: = Evolution of = reconstructive=20 techniques following endoscopic expanded = endonasal=20 approaches. Neurosurg = Focus=20 19:1E8, 2005
5.	Kassam A, Thomas A, = Carrau RL,=20 = Snyderman=20 CH, Mintz=20 A, =20 Gardner P, et=20 al.: Endoscopic reconstruction of the skull base = using a=20 pedicled nasoseptal flap. Neurosurgery in=20 press2008
6.	Kassam AB, Prevedello = DM,=20 = Thomas A,=20 = Gardner=20 P, Mintz=20 A, =20 Snyderman C, et=20 al.: Endoscopic endonasal pituitary = transposition for=20 transdorsum sellae approach to the = interpeduncular=20 cistern. Neurosurgery=20 62:57=9674, 2008
7.	Kassam AB, Thomas AJ,=20 = Snyderman=20 C, Carrau=20 R, =20 Gardner P, Mintz A, = et al.: Fully = endoscopic=20 expanded endonasal approach treating skull base = lesions=20 in pediatric patients. J = Neurosurg 106:2=20 Suppl75=9686, 2007
8.	Kassam A, Vescan AD,=20 = Carrau=20 RL, =20 Prevedello DM, Gardner P,=20 = Mintz AH,=20 et = al.: Expanded=20 endonasal approach: vidian canal as a landmark = to the=20 petrous internal carotid artery. J = Neurosurg=20 108:177=96183, 2008
9.	Pirris SM, Pollack IF,=20 = Snyderman=20 CH, =20 Carrau RL, Spiro RM, = Tyler-Kabara = E,=20 et = al.: Corridor=20 surgery: the current paradigm for skull base = surgery.=20 Childs = Nerv=20 Syst 23:377=96384, 2007