Childs Nerv Syst DOI 10.1007/s00381-015-2737-z
COMMENTARY
Technical note on hemispherotomy Helio R. Machado 1
Received: 31 March 2015 / Accepted: 22 April 2015 # Springer-Verlag Berlin Heidelberg 2015
Complications both peri and postoperative and surgical difficulties during anatomical hemispherectomies motivated Rasmussen, in 1974, to describe a new technique, the Functional Hemispherectomy [1]. The main argument at that time was that by performing a complete disconnection with preservation of brain tissue in the affected hemisphere, it would generate the same long-term results as the old technique. After that brilliant proposal, several other techniques appeared in the literature [2] depicting refinements of the original technique converging finally to the description of the hemispherotomies. This one almost immediately had some technical variants concerning either a vertical [3] or lateral approach [4–7]. All these techniques have in common the opening of the lateral ventricle which is typically exposed in its totality, from the frontal to the temporal horn, crossing the atrium. Anatomical landmarks are key to this procedure irrespective of small variations in the technique depending on the experience and technical skill of the surgeon. In this context, I read with interest the paper Vertical Extraventricular Functional Hemispherotomy: a New Variant for Hemispheric Disconnection. Technical Notes and Results in Three Patients, by Giordano et al., and I have some comments on this technique. The authors claim that their technique reduces the probability of hydrocephalus because of the reduced amount of brain tissue resected and minimal opening of CSF spaces.
Nevertheless, they applied the technique in only three patients and the traditional techniques, both the lateral [7] and the vertical approaches [3] with a much longer experience, have very low incidence of hydrocephalus and minimal resection of brain tissue [8]. Moreover, age at surgery (under 1 year of age) seems to be an important factor responsible for the occurrence of hydrocephalus in the postoperative period associated eventually with other factors as severity of the disease itself (as in hemimegalencephaly) [9]. One other point is that the technique described contrary to the traditional ones is very challenging because it does not rely on anatomical landmarks and corridors familiar to the neurosurgeons (peri-insular region, ventricles, medial temporal structures, fornices, etc.) but a very long route crossing the hemisphere through the white matter relying only in neuronavigation, which is sometimes very defiant due to known or unknown facts (brain shift, eventual malfunction, or error of the system). In conclusion, proposing a new surgical technique or a variant of a popular one requires convincing feasibility and/ or a clear reduction of morbidity/mortality and better results, which is not the case in my view.
References 1. 2.
* Helio R. Machado [email protected] 1
Center for Epilepsy Surgery in Children, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes 3900, 14049-900 Ribeirao Preto, Sao Paulo, Brazil
3.
4.
Villemure JG, Rasmussen T (1990) Functional hemispherectomy: methodology. J Epilepsy 3(Suppl):177–182 Villemure JG (2001) Functional hemispherectomy: evolution of technique and results in 65 cases. In: Epilepsy surgery, 2nd edn. Lippincott Williams & Wilkins, Philadelphia, pp 733–739 Delalande O, Pinard JM, Basdevant C, Gauthe M, Plouin P, Dulac O (1992) Hemispherotomy: a new procedure for central disconnection. Epilepsia 33(3 Suppl):99–100, Abstract Schramm J, Behrens E, Entzian W (1994) Hemispherical deafferentation: a modified functional hemispherectomy technique. Epilepsia 35(Suppl 8):71, Abstract
Childs Nerv Syst 5.
Schramm J, Kral T, Clusmann H (2001) Transsylvian keyhole functional hemispherectomy. Neurosurgery 49(4):891–901 6. Shimizu H, Maehara T (2000) Modification of peri-insular hemispherotomy and surgical results. Neurosurgery 47(2):367–373 7. Villemure JG, Mascott CR (1995) Peri-insular hemispherotomy: surgical principles and anatomy. Neurosurgery 37:975–981
8. 9.
De Ribaupierre S, Delalande O (2008) Hemispherotomy and other disconnective techniques. Neurosurg Focus 25(3), E14 Rocco D, Iannelli A (2000) Hemimegalencephaly and intractable epilepsy: complications of hemispherectomy and their correlations with the surgical technique. Pediatr Neurosurg 33:198–207
COMMENTARY
Technical note on hemispherotomy Helio R. Machado 1
Received: 31 March 2015 / Accepted: 22 April 2015 # Springer-Verlag Berlin Heidelberg 2015
Complications both peri and postoperative and surgical difficulties during anatomical hemispherectomies motivated Rasmussen, in 1974, to describe a new technique, the Functional Hemispherectomy [1]. The main argument at that time was that by performing a complete disconnection with preservation of brain tissue in the affected hemisphere, it would generate the same long-term results as the old technique. After that brilliant proposal, several other techniques appeared in the literature [2] depicting refinements of the original technique converging finally to the description of the hemispherotomies. This one almost immediately had some technical variants concerning either a vertical [3] or lateral approach [4–7]. All these techniques have in common the opening of the lateral ventricle which is typically exposed in its totality, from the frontal to the temporal horn, crossing the atrium. Anatomical landmarks are key to this procedure irrespective of small variations in the technique depending on the experience and technical skill of the surgeon. In this context, I read with interest the paper Vertical Extraventricular Functional Hemispherotomy: a New Variant for Hemispheric Disconnection. Technical Notes and Results in Three Patients, by Giordano et al., and I have some comments on this technique. The authors claim that their technique reduces the probability of hydrocephalus because of the reduced amount of brain tissue resected and minimal opening of CSF spaces.
Nevertheless, they applied the technique in only three patients and the traditional techniques, both the lateral [7] and the vertical approaches [3] with a much longer experience, have very low incidence of hydrocephalus and minimal resection of brain tissue [8]. Moreover, age at surgery (under 1 year of age) seems to be an important factor responsible for the occurrence of hydrocephalus in the postoperative period associated eventually with other factors as severity of the disease itself (as in hemimegalencephaly) [9]. One other point is that the technique described contrary to the traditional ones is very challenging because it does not rely on anatomical landmarks and corridors familiar to the neurosurgeons (peri-insular region, ventricles, medial temporal structures, fornices, etc.) but a very long route crossing the hemisphere through the white matter relying only in neuronavigation, which is sometimes very defiant due to known or unknown facts (brain shift, eventual malfunction, or error of the system). In conclusion, proposing a new surgical technique or a variant of a popular one requires convincing feasibility and/ or a clear reduction of morbidity/mortality and better results, which is not the case in my view.
References 1. 2.
* Helio R. Machado [email protected] 1
Center for Epilepsy Surgery in Children, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes 3900, 14049-900 Ribeirao Preto, Sao Paulo, Brazil
3.
4.
Villemure JG, Rasmussen T (1990) Functional hemispherectomy: methodology. J Epilepsy 3(Suppl):177–182 Villemure JG (2001) Functional hemispherectomy: evolution of technique and results in 65 cases. In: Epilepsy surgery, 2nd edn. Lippincott Williams & Wilkins, Philadelphia, pp 733–739 Delalande O, Pinard JM, Basdevant C, Gauthe M, Plouin P, Dulac O (1992) Hemispherotomy: a new procedure for central disconnection. Epilepsia 33(3 Suppl):99–100, Abstract Schramm J, Behrens E, Entzian W (1994) Hemispherical deafferentation: a modified functional hemispherectomy technique. Epilepsia 35(Suppl 8):71, Abstract
Childs Nerv Syst 5.
Schramm J, Kral T, Clusmann H (2001) Transsylvian keyhole functional hemispherectomy. Neurosurgery 49(4):891–901 6. Shimizu H, Maehara T (2000) Modification of peri-insular hemispherotomy and surgical results. Neurosurgery 47(2):367–373 7. Villemure JG, Mascott CR (1995) Peri-insular hemispherotomy: surgical principles and anatomy. Neurosurgery 37:975–981
8. 9.
De Ribaupierre S, Delalande O (2008) Hemispherotomy and other disconnective techniques. Neurosurg Focus 25(3), E14 Rocco D, Iannelli A (2000) Hemimegalencephaly and intractable epilepsy: complications of hemispherectomy and their correlations with the surgical technique. Pediatr Neurosurg 33:198–207
