Photomedicine and Laser Surgery Volume 33, Number 4, 2015 ª Mary Ann Liebert, Inc. Pp. 220–223 DOI: 10.1089/pho.2014.3847
Preparation of Nasoseptal Flap in Trans-Sphenoidal Surgery Using 2-l Thullium Laser: Technical Note Emiliano Passacantilli, PhD, MD,1 Gennaro Lapadula, MD,1 Federico Caporlingua, MD,1 Giulio Anichini, MD,1 Filippo Giovannetti, MD,2 Antonio Santoro,1 and Jacopo Lenzi, PhD, MD1
Abstract
Objective: The purpose of this study was to assess the feasibility of the use of the 2l-thulium laser in harvesting nasal septal flaps. Background data: Nasal septal flaps are routinely performed in almost every trans-sphenoidal surgery. The preservation of the arterial vasculature is a mainstay of the procedure. However, the margins of the flap should be sufficiently healthy to regenerate faster, reducing the risk of possible complications. Materials and methods: Eight patients underwent trans-sphenoidal surgery and removal of pituitary adenomas. Reparation of the defect was performed with the positioning of a rotational vascularized nasal-septal flap. The flaps were harvested with the aid of the 2l-thulium laser. Every patient was then monitored for 6 months through seriated endoscopic endonasal controls. Results: There were no complications related to the use of the laser, either intraoperatively, or postoperatively. The operative timing did not significantly differ from that of traditional techniques. Conclusions: The use of the 2lthulium laser for the harvesting of nasal septal vascularized flaps can be considered safe and feasible. The limited number of treated patients could be considered as the only restriction to the study. A larger study might have uncovered possible instrumentation-related complications, which were not observed in the present study.
Introduction
N
owadays, nasal septal flaps are largely used in trans-sphenoidal and skull base endoscopic procedures, to obtain a safe reconstruction of the cranial base. Hirsch described the first use of a nasal flap for the closure of a cerebrospinal fluid (CSF) fistula after hypophysectomy in 1952.1 The technique has gone through several changes; that is, its adaptation in endonasal endoscopic surgery as well as the drop out of rotational flaps with random blood supply, this one with a better definition of the nasal vasculature. The Hadad–Bassagasteguy’s flap2 currently is the most frequently practiced technique; here the flap is usually obtained from the septal mucosa through a classic transnasal approach. Preservation of the vascular pedicle, vascularized by branches of the posterior nasoseptal artery, is required to allow flap regeneration.3–5 Flaps can be obtained either by using a monopolar cautery or an adapted endoscopic blade. Modest bleeding of the flap margins is required to allow a better and faster repair. Both the instruments and technique for flap packing choice depend on the surgeon’s preferences as well as individual case flap size. As far as our surgical experience has shown, we have been lately evaluating the possibility to apply laser techniques for this purpose. 1 2
Thulium laser fibers were used in our Institution for surgical removal of intracranial meningiomas during microsurgical interventions, where they proved to have excellent properties in bleeding control6 and limited penetration through surrounding tissues.7 Their application was, therefore, extended to endoscopic third-ventriculostomy procedures8 and trans-sphenoidal surgery. Fibers’ flexibility as well as their size allowed for insertion of the laser inside the traditional endoscopic instrumentation so as to use it without any additional hindrance for the surgeon. In the present study, we will show our preliminary results with the use of 2l-thulium laser for preparation of nasal septal flap after trans-sphenoidal surgery in a selected group of patients. Both the surgical techniques and the technical features will be discussed. Methods
Eight patients with diagnosis of pituitary adenomas were selected for the purpose of this study. In order to obtain quite homogeneous data and surgical results, only patients with intrasellar, small-sized adenomas ( £ 1 cm) were selected. Every patient was told about the possibility of using
Department of Neurology and Psychiatry, Neurosurgery, ‘‘Sapienza’’ University of Rome, Rome Italy. Department of Neurology and Psychiatry, Maxillo-Facial Surgery, ‘‘Sapienza’’ University of Rome, Rome, Italy.
220
LASER FOR NASOSEPTAL FLAP HARVESTING
a laser during the surgical procedure; all patients signed a detailed informed consent. A 2lm, pulsed-wave thulium laser (Revolix Laser JR 15 W; Katlenburg-Lindau, Germany) was used during surgery, as well as traditional endoscopic instrumentation. Energy from the thulium laser was administered through a 0.73 mm diameter flexible microfiber (Percufib) inserted in a curved handpiece (Surgilas) designed for maneuvers under microscope and endoscope visualization. Three surgeons performed the surgeries; all the procedures were executed at the Institution of Neurology and Psychiatry of ‘‘Sapienza’’ University Rome, Neurosurgery Department. Detailed videos and photographic documentation are provided for all examined cases. Timing of laser use was recorded to compare it with timing of the same procedures conducted with our traditional instrumentation. For this purpose, the clinical files of eight patients operated on with the conventional technique (mainly monopolar cautery) were retrospectively analyzed to find the operating time of the flap harvesting. The control patients were demographically comparable with those operated on with the thulium laser. The operating times were compared with paired Student t test. Monitoring was performed through visual endoscopic control of the flap after 1 week, then 1 month, then 6 months, and, finally, 1 year from the operation. Surgical technique
A traditional endoscopic transnasal trans-sphenoidal approach was performed on all our patients. Patients were positioned with their heads elevated and slightly extended to allow full access to the nasal cavity. A four hands endoscopic technique according to Kassam had been adopted for all the aforementioned procedures.9,10 After defining the anatomy of the inferior, middle, and superior turbinate, the rostrum was localized. The middle turbinate was removed in order to obtain a better exposure of the posterior portion of the rostrum. The anterior wall of the sphenoidal sinus was exposed through limited rostrum opening, and then opened to reach the floor of the sella. The flap was designed according to the size and shape of the anticipated defect. We decided to harvest the flap on the same side of the turbinectomy, where a broader surgical route allows a better visualization and instrument manipulation. Thulium laser fibers were then inserted to package the nasal septal flap before proceeding with surgical removal of the tumor. The fibers are flexible and are 0.73 mm wide; they have been used both alone and through an endoscope-adapted handpiece (Surgilas). Fibers were connected to a small operating system, which permitted real-time control of Watt settings and Joules administration. Watt settings were chosen by the surgeon on the basis of the energy that needed to be delivered on the surgical field: higher values correspond to stronger coagulation and thermal damage. The size of the cut and thermal damage are related to the tip of the fiber, which is extremely thin and precise. As we found in a previous study, penetration of thermal damage is limited to £ 2 mm from the tip of the fiber using high Watt settings ( ‡ 12).6 Moreover, the laser wavelength is selectively absorbed by water; this feature limits its dispersion through relatively dry tissues such as bone and/or cartilage. For an endoscopic procedure, the laser was used for incisions and definition of nasal septal flap margins. One of
221
the operators manipulated the laser and the endoscopeadapted aspirator, and the other one held the endoscope and gently irrigated the surgical field; constant irrigation and aspiration reduced smoke production, which can be disturbing during laser cautery. Small dimensions and flexibility of the fibers allowed manipulation without significant hindrance for the surgeons. Two parallel incisions were performed on the septum, one inferiorly, directed from the posterior to the anterior portion of the septum parallel to the maxillary crest, and the other one superiorly, *1 cm below the olfactory sulcus to avoid damage to olfactory mucosa (Fig. 1). The superior incision was extended laterally to cross the rostrum of the sphenoid sinus and reach the ostium sphenoidalis. The inferior incision was brought to the posterior margin of the septum, and then turned laterally to reach the anterior margin of the choana, just below the floor of the sphenoid sinus. A third, anterior, vertical incision was made to connect the previous two and obtain a quadrangular area of mucosa with a posterior pedicle. The margins of the flap were controlled to ensure that both periostium and perichondrium had been properly incised. Elevation of the mucosal flap was then performed using a Cottle dissector, proceeding from the anterior to the posterior portion of the flap. Careful subperiosteal dissection was performed to avoid lacerations. The flap was then rotated on the retropharyngeal space (Fig. 2) and the operation was completed through the opening of the floor of the sella and tumor removal. Reconstruction was then performed through a multiple layers technique, placing hemostatic fibrin glues (Tissucol) and nets (Surgicel) on the surgical opening, then filling the flap inside the dural margins in order to ease its attachment and obtain a better resistance against intracranial pressure. Additional layers of hemostatic materials were used to uniformly cover the mucosal surface of the flap.
FIG. 1. The nasoseptal flap incision at the anterior nasal cavity using 2-l thullium laser. The middle turbinate is at the left of the image.
222
FIG. 2. After a posterior septectomy, the nasoseptal flap is rotated inside the surgical defect and fills it completely (center). The flap peduncle is located posteriorly and inferiorly. Results
A laser was used only during packing of the nasal septal flap, whereas the hemostasis on the surgical route was obtained with traditional endoscope-adapted cautery. All treated patients showed excellent nasal septal flap attachment without any signs of CSF leak at postoperative clinical controls (Fig. 3). Neither side effects nor complications related to laser manipulation were noticed. A comparison between laser and traditional instrumentation procedures operating timings was made (Table 1). Discussion
Nasoseptal flap packing has become a routine procedure in cranial base reconstruction after trans-sphenoidal surgery.11 Surgical technique must adapt to each case, depending upon the size of the reconstruction required and the risk of postoperative CSF leak. The borders of the flap are defined on the septum mucosa using a surgical blade and/or a monopolar cautery. For the aim of the present study, two considerations led us to evaluate the use of 2-l thulium laser. First of all, after our experience with microsurgical procedures such as surgical removal of intracranial meningiomas,6 we wanted to assess their features also during endoscopic surgery. Second, we meant to study alternative instrumentation for flap packing, mainly because the interest in these reconstruction techniques is constantly growing, and it is our conviction that all possible alternatives should be verified to improve both the timing of the procedure and the functional outcome. Thulium laser in clinical practice was introduced in 2005, when it was used in urological surgery for bladder incision
PASSACANTILLI ET AL.
FIG. 3. Complete regeneration of the mucosa of the sphenoid sinus and of the pedicled septal flap 6 months after the surgery. Note that the flap rotates inside the sphenoid sinus cavity and covers it. and vaporesection of the prostate.12,13 Furthermore, it was also used in neurosurgery during third-ventriculostomy procedures.8 At our institution, we started to apply it during microsurgical removal of intracranial meningiomas, in addition to using traditional microsurgical instrumentation [Cavitron UltraSonic Aspirator (CUSA) and bipolar cautery]. Its physical features allow using it in water medium with modest thermal dispersion, which makes it ideal for intracranial surgery. As we demonstrated in a previous article, histological alterations are limited to < 2 mm if compared with the application of the fiber.7 In oncological surgery, lasers can be applied both to coagulate small vessels of the tumor and to cut it to obtain a piece removal. Smoke dispersion can be observed but it is easily resolved with continued water irrigation by the assistant. Because of both the diameter of the fiber (0.73 mm) and the limited thermal
Table 1. Operating Timings Analyzed on Paired Patients (T = 10.46; 95% CI = 15.2–24.21; p < 0.0001) Oprating timings (min) Pt
Monopolar cautery
Thulium laser
1 2 3 4 5 6 7 8
40 42 38 45 53 46 43 42
20 25 23 17 27 25 24 30
LASER FOR NASOSEPTAL FLAP HARVESTING
dispersion, lasers show excellent cut properties. At lower settings they can be used to cut not only tumors but also other tissues, without thermal damage to the surrounding structures, which is the main feature that led us to use them during nasal septal packing. When they are applied to endoscopic instrumentation, the flexible fiber is long enough to reach the depth of the endoscopic view, and the small diameter allows for using it with precise direction without hindrance for the surgeon. The borders of the flap are defined because of careful laser application at a maximum setting of 10 W. Bleedings from the margins are controlled by laser applications, but limited shrinking of the flap can be observed. Liu et al. noted that excessive use of cauterization should be avoided in order to reduce the surface of the flap itself, which could shrink after excessive coagulation.10 Despite that this is one of the risks encountered, in our experience, flap shrinkage is limited when careful, step-bystep coagulation is performed, without prolonged application of the cauterization; conversely, tedious bleedings from the mucosa are well controlled or avoided. Despite no histological analysis having been made to compared laser tissue damage to that caused by conventional instrumentation, we believe that it may be inferred from a previous study on meningioma surgery.6 The thulium laser causes a narrow central crater, a vaporized zone with a honeycomb structure, and a peripheral shrunken zone with nuclear pyknosis. The three zones are well defined and no signs of hemorrhages were visualized.7 Bipolar and monopolar cautery cause similar damage, but the three zones are larger and less defined.7 A narrower vaporization zone might be responsible for a faster flap regeneration. After the definition of the margins, subperiosteal elevation of the flap is performed using Cottle dissector, thus leaving the flap ready to be used. No laser side effects have been noted either during the surgical procedure or at clinical and radiological follow-up. None of the patients showed postoperative CSF leakage, and the nasal septal flap showed perfect attachment at follow-up controls. Conclusions
On the basis of the results obtained with this small cohort of patients, 2l-thulium laser is likely to be used safely in trans-sphenoidal surgery for packaging of the nasal septal flap. Additional data and more extended series are required to assess its utility during different endoscopic transnasal procedures.
223
2. Hadad G, Bassagasteguy L, Carrau RL, et al. A novel reconstructive technique after endoscopic expanded endonasal approaches: vascular pedicle nasoseptal flap. Laryngoscope 2006;116:1882–1886. 3. Fortes FS, Carrau RL, Snyderman CH, et al. The posterior pedicle inferior turbinate flap: a new vascularized flap for skull base reconstruction. Laryngoscope 2007;117:1329– 1332. 4. Yoshioka N, Rhoton AL, Jr. Vascular anatomy of the anteriorly based pericranial flap. Neurosurgery 2005;57(Suppl 1):11–16. 5. Hadad G, Rivera-Serrano CM, Bassagaisteguy LH, et al. Anterior pedicle lateral nasal wall flap: a novel technique for the reconstruction of anterior skull base defects. Laryngoscope 2011;121:1606–1610. 6. Passacantilli E, Anichini G, Lapadula G, et al. Assessment of the utility of the 2-l thulium laser in surgical removal of intracranial meningiomas. Lasers Surg Med 2013;45: 148–154. 7. Passacantilli E, Antonelli M, D’Amico A, Delfinis CP, Anichini G, Lenzi J. Neurosurgical applications of the 2lm thulium laser: histological evaluation of meningiomas in comparison to bipolar forceps and an ultrasonic aspirator. Photomed Laser Surg 2012;30:2862–2892. 8. Ludwig HC, Kruschat T, Knobloch T, Teichmann HO, Rostasy K, Rohde V. First experiences with a 2.0-microm near infrared laser system for neuroendoscopy. Neurosurg Rev 2007:30:195–201. 9. Kassam AB, Thomas A, Carrau RL, Snyderman CH, Vescan A, Prevedello D. Endoscopic reconstruction of the cranial base using a pedicled nasoseptal flap. Neurosurgery 2008;63(1 Suppl 1):ONS44–ONS53. 10. Liu JK, Schmidt BA, Choundhry OJ, Shukla PA, Eloy JA. Surgical nuances of naso-septal flap reconstruction of cranial base defects with high-flow cerebro-spinal fluid leaks after endoscopic skull base surgery. Neurosurg Focus 2012; 32:E7. 11. Kassam AB, Prevedello DM, Carrau RL, et al. Endoscopic endonasal skull base surgery: analysis of complications in the authors’ initial 800 patients. A review. J Neurosurg 2011;114:1544–1568. 12. Bach T, Herrmann TR, Ganzer R, Burchardt M, Burchardt M, Gross AJ. Revolix vaporesection of the prostate: initial results after 54 patients with an one year follow-up. World J Urol 2007;25:257–262. 13. Wendt-Nordahl G, Huckele S, Honeck P, et al. Systematic evaluation of a recently introduced 2-microm continuouswave thulium laser for vaporesection of the prostate. J Endourol 2008;22:1041–1045.
Author Disclosure Statement
No competing financial interests exist. References
1. Hirsch O. Successful closure of cerebrospinal fluid rhinorrhea by endonasal surgery. AMA Arch Otolaryngol 1952;56:1–12.
Address correspondence to: Gennaro Lapadula Via Attilio Mori n. 7 00176, Rome Italy E-mail: [email protected]
Preparation of Nasoseptal Flap in Trans-Sphenoidal Surgery Using 2-l Thullium Laser: Technical Note Emiliano Passacantilli, PhD, MD,1 Gennaro Lapadula, MD,1 Federico Caporlingua, MD,1 Giulio Anichini, MD,1 Filippo Giovannetti, MD,2 Antonio Santoro,1 and Jacopo Lenzi, PhD, MD1
Abstract
Objective: The purpose of this study was to assess the feasibility of the use of the 2l-thulium laser in harvesting nasal septal flaps. Background data: Nasal septal flaps are routinely performed in almost every trans-sphenoidal surgery. The preservation of the arterial vasculature is a mainstay of the procedure. However, the margins of the flap should be sufficiently healthy to regenerate faster, reducing the risk of possible complications. Materials and methods: Eight patients underwent trans-sphenoidal surgery and removal of pituitary adenomas. Reparation of the defect was performed with the positioning of a rotational vascularized nasal-septal flap. The flaps were harvested with the aid of the 2l-thulium laser. Every patient was then monitored for 6 months through seriated endoscopic endonasal controls. Results: There were no complications related to the use of the laser, either intraoperatively, or postoperatively. The operative timing did not significantly differ from that of traditional techniques. Conclusions: The use of the 2lthulium laser for the harvesting of nasal septal vascularized flaps can be considered safe and feasible. The limited number of treated patients could be considered as the only restriction to the study. A larger study might have uncovered possible instrumentation-related complications, which were not observed in the present study.
Introduction
N
owadays, nasal septal flaps are largely used in trans-sphenoidal and skull base endoscopic procedures, to obtain a safe reconstruction of the cranial base. Hirsch described the first use of a nasal flap for the closure of a cerebrospinal fluid (CSF) fistula after hypophysectomy in 1952.1 The technique has gone through several changes; that is, its adaptation in endonasal endoscopic surgery as well as the drop out of rotational flaps with random blood supply, this one with a better definition of the nasal vasculature. The Hadad–Bassagasteguy’s flap2 currently is the most frequently practiced technique; here the flap is usually obtained from the septal mucosa through a classic transnasal approach. Preservation of the vascular pedicle, vascularized by branches of the posterior nasoseptal artery, is required to allow flap regeneration.3–5 Flaps can be obtained either by using a monopolar cautery or an adapted endoscopic blade. Modest bleeding of the flap margins is required to allow a better and faster repair. Both the instruments and technique for flap packing choice depend on the surgeon’s preferences as well as individual case flap size. As far as our surgical experience has shown, we have been lately evaluating the possibility to apply laser techniques for this purpose. 1 2
Thulium laser fibers were used in our Institution for surgical removal of intracranial meningiomas during microsurgical interventions, where they proved to have excellent properties in bleeding control6 and limited penetration through surrounding tissues.7 Their application was, therefore, extended to endoscopic third-ventriculostomy procedures8 and trans-sphenoidal surgery. Fibers’ flexibility as well as their size allowed for insertion of the laser inside the traditional endoscopic instrumentation so as to use it without any additional hindrance for the surgeon. In the present study, we will show our preliminary results with the use of 2l-thulium laser for preparation of nasal septal flap after trans-sphenoidal surgery in a selected group of patients. Both the surgical techniques and the technical features will be discussed. Methods
Eight patients with diagnosis of pituitary adenomas were selected for the purpose of this study. In order to obtain quite homogeneous data and surgical results, only patients with intrasellar, small-sized adenomas ( £ 1 cm) were selected. Every patient was told about the possibility of using
Department of Neurology and Psychiatry, Neurosurgery, ‘‘Sapienza’’ University of Rome, Rome Italy. Department of Neurology and Psychiatry, Maxillo-Facial Surgery, ‘‘Sapienza’’ University of Rome, Rome, Italy.
220
LASER FOR NASOSEPTAL FLAP HARVESTING
a laser during the surgical procedure; all patients signed a detailed informed consent. A 2lm, pulsed-wave thulium laser (Revolix Laser JR 15 W; Katlenburg-Lindau, Germany) was used during surgery, as well as traditional endoscopic instrumentation. Energy from the thulium laser was administered through a 0.73 mm diameter flexible microfiber (Percufib) inserted in a curved handpiece (Surgilas) designed for maneuvers under microscope and endoscope visualization. Three surgeons performed the surgeries; all the procedures were executed at the Institution of Neurology and Psychiatry of ‘‘Sapienza’’ University Rome, Neurosurgery Department. Detailed videos and photographic documentation are provided for all examined cases. Timing of laser use was recorded to compare it with timing of the same procedures conducted with our traditional instrumentation. For this purpose, the clinical files of eight patients operated on with the conventional technique (mainly monopolar cautery) were retrospectively analyzed to find the operating time of the flap harvesting. The control patients were demographically comparable with those operated on with the thulium laser. The operating times were compared with paired Student t test. Monitoring was performed through visual endoscopic control of the flap after 1 week, then 1 month, then 6 months, and, finally, 1 year from the operation. Surgical technique
A traditional endoscopic transnasal trans-sphenoidal approach was performed on all our patients. Patients were positioned with their heads elevated and slightly extended to allow full access to the nasal cavity. A four hands endoscopic technique according to Kassam had been adopted for all the aforementioned procedures.9,10 After defining the anatomy of the inferior, middle, and superior turbinate, the rostrum was localized. The middle turbinate was removed in order to obtain a better exposure of the posterior portion of the rostrum. The anterior wall of the sphenoidal sinus was exposed through limited rostrum opening, and then opened to reach the floor of the sella. The flap was designed according to the size and shape of the anticipated defect. We decided to harvest the flap on the same side of the turbinectomy, where a broader surgical route allows a better visualization and instrument manipulation. Thulium laser fibers were then inserted to package the nasal septal flap before proceeding with surgical removal of the tumor. The fibers are flexible and are 0.73 mm wide; they have been used both alone and through an endoscope-adapted handpiece (Surgilas). Fibers were connected to a small operating system, which permitted real-time control of Watt settings and Joules administration. Watt settings were chosen by the surgeon on the basis of the energy that needed to be delivered on the surgical field: higher values correspond to stronger coagulation and thermal damage. The size of the cut and thermal damage are related to the tip of the fiber, which is extremely thin and precise. As we found in a previous study, penetration of thermal damage is limited to £ 2 mm from the tip of the fiber using high Watt settings ( ‡ 12).6 Moreover, the laser wavelength is selectively absorbed by water; this feature limits its dispersion through relatively dry tissues such as bone and/or cartilage. For an endoscopic procedure, the laser was used for incisions and definition of nasal septal flap margins. One of
221
the operators manipulated the laser and the endoscopeadapted aspirator, and the other one held the endoscope and gently irrigated the surgical field; constant irrigation and aspiration reduced smoke production, which can be disturbing during laser cautery. Small dimensions and flexibility of the fibers allowed manipulation without significant hindrance for the surgeons. Two parallel incisions were performed on the septum, one inferiorly, directed from the posterior to the anterior portion of the septum parallel to the maxillary crest, and the other one superiorly, *1 cm below the olfactory sulcus to avoid damage to olfactory mucosa (Fig. 1). The superior incision was extended laterally to cross the rostrum of the sphenoid sinus and reach the ostium sphenoidalis. The inferior incision was brought to the posterior margin of the septum, and then turned laterally to reach the anterior margin of the choana, just below the floor of the sphenoid sinus. A third, anterior, vertical incision was made to connect the previous two and obtain a quadrangular area of mucosa with a posterior pedicle. The margins of the flap were controlled to ensure that both periostium and perichondrium had been properly incised. Elevation of the mucosal flap was then performed using a Cottle dissector, proceeding from the anterior to the posterior portion of the flap. Careful subperiosteal dissection was performed to avoid lacerations. The flap was then rotated on the retropharyngeal space (Fig. 2) and the operation was completed through the opening of the floor of the sella and tumor removal. Reconstruction was then performed through a multiple layers technique, placing hemostatic fibrin glues (Tissucol) and nets (Surgicel) on the surgical opening, then filling the flap inside the dural margins in order to ease its attachment and obtain a better resistance against intracranial pressure. Additional layers of hemostatic materials were used to uniformly cover the mucosal surface of the flap.
FIG. 1. The nasoseptal flap incision at the anterior nasal cavity using 2-l thullium laser. The middle turbinate is at the left of the image.
222
FIG. 2. After a posterior septectomy, the nasoseptal flap is rotated inside the surgical defect and fills it completely (center). The flap peduncle is located posteriorly and inferiorly. Results
A laser was used only during packing of the nasal septal flap, whereas the hemostasis on the surgical route was obtained with traditional endoscope-adapted cautery. All treated patients showed excellent nasal septal flap attachment without any signs of CSF leak at postoperative clinical controls (Fig. 3). Neither side effects nor complications related to laser manipulation were noticed. A comparison between laser and traditional instrumentation procedures operating timings was made (Table 1). Discussion
Nasoseptal flap packing has become a routine procedure in cranial base reconstruction after trans-sphenoidal surgery.11 Surgical technique must adapt to each case, depending upon the size of the reconstruction required and the risk of postoperative CSF leak. The borders of the flap are defined on the septum mucosa using a surgical blade and/or a monopolar cautery. For the aim of the present study, two considerations led us to evaluate the use of 2-l thulium laser. First of all, after our experience with microsurgical procedures such as surgical removal of intracranial meningiomas,6 we wanted to assess their features also during endoscopic surgery. Second, we meant to study alternative instrumentation for flap packing, mainly because the interest in these reconstruction techniques is constantly growing, and it is our conviction that all possible alternatives should be verified to improve both the timing of the procedure and the functional outcome. Thulium laser in clinical practice was introduced in 2005, when it was used in urological surgery for bladder incision
PASSACANTILLI ET AL.
FIG. 3. Complete regeneration of the mucosa of the sphenoid sinus and of the pedicled septal flap 6 months after the surgery. Note that the flap rotates inside the sphenoid sinus cavity and covers it. and vaporesection of the prostate.12,13 Furthermore, it was also used in neurosurgery during third-ventriculostomy procedures.8 At our institution, we started to apply it during microsurgical removal of intracranial meningiomas, in addition to using traditional microsurgical instrumentation [Cavitron UltraSonic Aspirator (CUSA) and bipolar cautery]. Its physical features allow using it in water medium with modest thermal dispersion, which makes it ideal for intracranial surgery. As we demonstrated in a previous article, histological alterations are limited to < 2 mm if compared with the application of the fiber.7 In oncological surgery, lasers can be applied both to coagulate small vessels of the tumor and to cut it to obtain a piece removal. Smoke dispersion can be observed but it is easily resolved with continued water irrigation by the assistant. Because of both the diameter of the fiber (0.73 mm) and the limited thermal
Table 1. Operating Timings Analyzed on Paired Patients (T = 10.46; 95% CI = 15.2–24.21; p < 0.0001) Oprating timings (min) Pt
Monopolar cautery
Thulium laser
1 2 3 4 5 6 7 8
40 42 38 45 53 46 43 42
20 25 23 17 27 25 24 30
LASER FOR NASOSEPTAL FLAP HARVESTING
dispersion, lasers show excellent cut properties. At lower settings they can be used to cut not only tumors but also other tissues, without thermal damage to the surrounding structures, which is the main feature that led us to use them during nasal septal packing. When they are applied to endoscopic instrumentation, the flexible fiber is long enough to reach the depth of the endoscopic view, and the small diameter allows for using it with precise direction without hindrance for the surgeon. The borders of the flap are defined because of careful laser application at a maximum setting of 10 W. Bleedings from the margins are controlled by laser applications, but limited shrinking of the flap can be observed. Liu et al. noted that excessive use of cauterization should be avoided in order to reduce the surface of the flap itself, which could shrink after excessive coagulation.10 Despite that this is one of the risks encountered, in our experience, flap shrinkage is limited when careful, step-bystep coagulation is performed, without prolonged application of the cauterization; conversely, tedious bleedings from the mucosa are well controlled or avoided. Despite no histological analysis having been made to compared laser tissue damage to that caused by conventional instrumentation, we believe that it may be inferred from a previous study on meningioma surgery.6 The thulium laser causes a narrow central crater, a vaporized zone with a honeycomb structure, and a peripheral shrunken zone with nuclear pyknosis. The three zones are well defined and no signs of hemorrhages were visualized.7 Bipolar and monopolar cautery cause similar damage, but the three zones are larger and less defined.7 A narrower vaporization zone might be responsible for a faster flap regeneration. After the definition of the margins, subperiosteal elevation of the flap is performed using Cottle dissector, thus leaving the flap ready to be used. No laser side effects have been noted either during the surgical procedure or at clinical and radiological follow-up. None of the patients showed postoperative CSF leakage, and the nasal septal flap showed perfect attachment at follow-up controls. Conclusions
On the basis of the results obtained with this small cohort of patients, 2l-thulium laser is likely to be used safely in trans-sphenoidal surgery for packaging of the nasal septal flap. Additional data and more extended series are required to assess its utility during different endoscopic transnasal procedures.
223
2. Hadad G, Bassagasteguy L, Carrau RL, et al. A novel reconstructive technique after endoscopic expanded endonasal approaches: vascular pedicle nasoseptal flap. Laryngoscope 2006;116:1882–1886. 3. Fortes FS, Carrau RL, Snyderman CH, et al. The posterior pedicle inferior turbinate flap: a new vascularized flap for skull base reconstruction. Laryngoscope 2007;117:1329– 1332. 4. Yoshioka N, Rhoton AL, Jr. Vascular anatomy of the anteriorly based pericranial flap. Neurosurgery 2005;57(Suppl 1):11–16. 5. Hadad G, Rivera-Serrano CM, Bassagaisteguy LH, et al. Anterior pedicle lateral nasal wall flap: a novel technique for the reconstruction of anterior skull base defects. Laryngoscope 2011;121:1606–1610. 6. Passacantilli E, Anichini G, Lapadula G, et al. Assessment of the utility of the 2-l thulium laser in surgical removal of intracranial meningiomas. Lasers Surg Med 2013;45: 148–154. 7. Passacantilli E, Antonelli M, D’Amico A, Delfinis CP, Anichini G, Lenzi J. Neurosurgical applications of the 2lm thulium laser: histological evaluation of meningiomas in comparison to bipolar forceps and an ultrasonic aspirator. Photomed Laser Surg 2012;30:2862–2892. 8. Ludwig HC, Kruschat T, Knobloch T, Teichmann HO, Rostasy K, Rohde V. First experiences with a 2.0-microm near infrared laser system for neuroendoscopy. Neurosurg Rev 2007:30:195–201. 9. Kassam AB, Thomas A, Carrau RL, Snyderman CH, Vescan A, Prevedello D. Endoscopic reconstruction of the cranial base using a pedicled nasoseptal flap. Neurosurgery 2008;63(1 Suppl 1):ONS44–ONS53. 10. Liu JK, Schmidt BA, Choundhry OJ, Shukla PA, Eloy JA. Surgical nuances of naso-septal flap reconstruction of cranial base defects with high-flow cerebro-spinal fluid leaks after endoscopic skull base surgery. Neurosurg Focus 2012; 32:E7. 11. Kassam AB, Prevedello DM, Carrau RL, et al. Endoscopic endonasal skull base surgery: analysis of complications in the authors’ initial 800 patients. A review. J Neurosurg 2011;114:1544–1568. 12. Bach T, Herrmann TR, Ganzer R, Burchardt M, Burchardt M, Gross AJ. Revolix vaporesection of the prostate: initial results after 54 patients with an one year follow-up. World J Urol 2007;25:257–262. 13. Wendt-Nordahl G, Huckele S, Honeck P, et al. Systematic evaluation of a recently introduced 2-microm continuouswave thulium laser for vaporesection of the prostate. J Endourol 2008;22:1041–1045.
Author Disclosure Statement
No competing financial interests exist. References
1. Hirsch O. Successful closure of cerebrospinal fluid rhinorrhea by endonasal surgery. AMA Arch Otolaryngol 1952;56:1–12.
Address correspondence to: Gennaro Lapadula Via Attilio Mori n. 7 00176, Rome Italy E-mail: [email protected]
