Predictive Factors of Unfavorable Events After Gamma Knife Radiosurgery for Vestibular Schwannoma.

OBJECTIVE: Gamma Knife radiosurgery (GKS) for the treatment of vestibular schwannoma (VS) introduces risks to the facial nerve and auditory perception and may involve post-treatment complications such as pseudoprogression, hydrocephalus, and other cranial neuropathies. This study of patients with VS who underwent GKS investigated radiosurgical results, focusing on post-treatment complications and identifying the factors that predict such complications. METHODS: We undertook a retrospective review of all VS patients treated with the Perfexion Leksell Gamma Knife between November 2007 and October 2010 at our institution. Patients who underwent at least 12 months of clinical and radiologic assessments before and after GKS were included. RESULTS: All 235 patients were included in the analyses reported here. The 5-year serviceable hearing and facial nerve preservation values were 73.9% and 94.3%, respectively. Following GKS, 43 patients (18.30%) showed pseudoprogression, 15 (6.38%) exhibited hydrocephalus, 22 (9.36%) showed trigeminal neuropathy, 14 (5.96%) showed vertigo, and 25 (10.64%) showed facial myokymia. According to multivariate analysis, solid tumor nature was significantly associated with pseudoprogression and patient age was significantly associated with hydrocephalus. Patients receiving margin doses ≥13 Gy had a significantly higher probability of loss of serviceable hearing. Patients with smaller tumors had a trigeminal nerve preservation rate comparable with patients harboring larger tumors. Patients receiving margin doses <13 Gy or older patients had a significantly higher probability of vestibular nerve dysfunction. CONCLUSIONS: Further prospective studies should be designed to provide further insight into the exact relationship between the predictive factors we investigated and post-treatment complications.

Implications of Vestibular Schwannoma Consistency: Analysis of 140 Cases Regarding Radiologic and Clinical Features.

OBJECTIVE: To evaluate the effects of vestibular schwannoma (VS) consistency on internal auditory canal (IAC) widening, magnetic resonance imaging appearance, presenting symptoms, and facial nerve outcome. MATERIAL AND METHODS: We performed a retrospective analysis of 140 consecutive patients presenting with unilateral VS who underwent surgical treatment at the Department of Neurosurgery, Tuebingen University, Germany. Operative videos were analyzed, and the tumors were classified into soft and firm according to resectability with an ultrasonic aspirator at 40% power. IAC opening was measured in preoperative bone-window computed tomography on the pathologic and healthy sides, and the percentage of widening between both sides was calculated. Tumor signal intensity was assessed on T2-weighted magnetic resonance imaging scans. Preoperative and postoperative findings in the patient reports were documented. RESULTS: Widening of the IAC due to presence of the VS occurred in 118 patients (84.3%). The degree of IAC widening on the tumor side compared to the other side ranged from 0.1 to 10.1 mm (mean 2.6 mm). The mean widening of the IAC in relation to the healthy side was 1.9 mm in soft tumors and 3.6 mm in firm tumors. A significant correlation was found between tumor consistency and degree of widening of the IAC (P < 0.0001). No significant correlation was found between tumor intensity (on T2-weighted imaging) and tumor consistency. In the early postoperative course, patients with soft tumors had better facial nerve function than those having firm tumors. However, at the last examination no difference between both groups was found. CONCLUSION: The consistency of VS has an impact on the immediate postoperative outcome. Widening on bony computed tomography scan, but not T2 intensity on magnetic resonance imaging, predicts whether the tumor is soft or firm.

Surgical Strategy and Facial Nerve Outcomes in Petrous Bone Cholesteatoma.

OBJECTIVE: To review the classification and management of petrous bone cholesteatomas (PBCs) at our center and the outcomes of facial nerve (FN) management in these lesions. METHODS: This was a retrospective study. The setting was a quaternary referral center for skull base pathology in Italy. A total of 200 patients with 201 PBCs were included in the study. All patients diagnosed radiologically with PBCs were classified according to the Sanna classification. All patients were surgically treated and followed up with radiology. The main outcome measures - classification of PBCs, the surgical approach used, disease control, and FN outcomes - were analyzed. RESULTS: Supralabyrinthine PBCs were the most common type with 92 cases (45.8%) followed by the massive PBCs with 72 cases (35.8%). Preservation of preoperative FN function was highest in the infralabyrinthine (72.2%) and infralabyrinthine-apical (73.3%) types. The transotic approach was used in 66 cases (32.8%) in this series. The modified transcochlear approach type A was applied in 55 cases (27.3%). Active management of the nerve (rerouting, anastomosis, or grafting) was required in 53 cases (26.4%). Postoperatively, of the 116 cases with FN House-Brackmann grade I and II, 107 cases (92.2%) retained the same grade or improved. Recurrence was seen in 7 cases (3.5%). The mean duration of follow-up was 6.3 years. CONCLUSIONS: Radical disease clearance must take precedence over hearing and FN preservation in PBCs. Active FN management, including rerouting, end-to-end anastomosis, and cable nerve grafting, routinely come to play in the surgical management of PBCs, and the postoperative FN results after such interventions can be satisfactory in most cases.

[Multiple erythema migrans and facial nerve paralysis: clinical manifestations of early disseminated Lyme borreliosis]. / Multilokuläre Erythemata migrantia und Fazialisparese : Klinische Manifestationsformen der disseminierten Frühinfektion der Lyme-Borreliose.

Lyme borreliosis is a common vector-borne disease in Europe. The infection follows different stages with a broad variability of clinical symptoms and manifestations in different organs. A 49-year-old man presented with flu-like symptoms, facial nerve paralysis and multiple erythematous macular on his trunk and extremities. We diagnosed Lyme disease (stage II) with facial nerve paralysis and multiple erythema migrans. Intravenous ceftriaxone led to complete healing of hissymptoms within 2 weeks.

Predictive factors influencing facial nerve outcomes in surgery for small-sized vestibular schwannoma.

CONCLUSION: The most important predictive factor of facial nerve outcome in surgery for small-sized vestibular schwannoma (VS) is the adhesion between the tumor and the facial nerve. OBJECTIVES: To compare the facial nerve outcomes between middle cranial fossa (MCF) and translabyrinthine (TL) approaches, and to analyze the preoperative and intraoperative factors influencing facial nerve outcome after small VS surgery in our neurotologic department. METHODS: A total of 29 patients were retrospectively analyzed, with 16 in the MCF group and 13 in the TL group. Facial function was serially evaluated according to the House-Brackmann classification at 7 days, 1 month, 3 months, 6 months, and 1 year postoperatively. The effects of variables such as the surgical approach, tumor size, nerve origin, extrameatal extension, intraoperative tumor adhesion to the facial nerve, and facial nerve displacement were determined. RESULTS: Early and late facial nerve outcomes showed no significant correlation with surgical approach, tumor origin, tumor size, extrameatal extension, or facial nerve displacement pattern. However, a significant correlation was observed with tumor adhesion to the facial nerve and facial nerve outcomes.

A survey of facial nerve dissection techniques in benign parotid surgery among maxillofacial and ear, nose, and throat surgeons in Nigeria.

OBJECTIVE: The aim of the present study is to identify the facial nerve dissection technique routinely used during parotidectomy for benign parotid tumors by Nigerian Oral and Maxillofacial (OMF) and Ear, Nose, and Throat (ENT) Surgeons. MATERIALS AND METHODS: A questionnaire-based study was conducted among Oral and Maxillofacial and Ear, Nose, and Throat Surgeons in Nigeria, on their experience with antegrade and retrograde facial nerve dissection techniques in parotid surgery. The respondents were asked to indicate their choice of dissection techniques in revision parotidectomy, limited superficial parotidectomy, and in obese patients with large tumors. They were also asked to indicate if they routinely used perioperative facial nerve monitoring devices in parotid surgery for benign tumors. RESULT: About half (47.5%) of them routinely used the antegrade technique, while only a few (12.5%) used the retrograde technique. A large number of them (40%), however, used a combination of antegrade and retrograde routinely. Technical ease was the main reason for the choice of technique. The antegrade technique was the technique of choice by most respondents for revision parotidectomy (60%) and limited superficial parotidectomy (62%). However, the retrograde approach was the technique of choice by most of them (47%) in case of parotidectomy in obese patients with large tumors. The routine use of perioperative facial nerve monitoring devices is an uncommon practice among OMF and ENT surgeons in Nigeria. CONCLUSIONS: The antegrade approach for facial nerve dissection is the most common technique used in parotid surgery by Nigerian OMF and ENT surgeons. Nigerian surgeons need to consider the retrograde approach in selected cases of parotid surgery especially for localized tumors that are amenable to limited superficial parotidectomy. Inclusion of perioperative facial nerve monitoring devices is also advocated.

Factors associated with preservation of facial nerve function after surgical resection of vestibular schwannoma.

Avoidance of facial nerve palsy is one of the major goals of vestibular schwannoma (VS) microsurgery. In this study, we examined the significance of previously implicated prognostic factors (age, tumor size, the extent of resection and the surgical approach) on post-operative facial nerve function. We selected all VS patients from prospectively collected database (1984-2009) who underwent microsurgical resection as their initial treatment for histopathologically confirmed VS. The effect of variables such as surgical approach, tumor size, patient age and extent of resection on rates facial nerve dysfunction after surgery, were analyzed using multivariate logistic regression. Patients with preoperative facial nerve dysfunction (House-Brackman [HB] score 3 or higher) were excluded, and HB grade of 1 or 2 at the last follow-up visit was defined as "facial nerve preservation." A total of 624 VS patients were included in this study. Multivariate logistic regression analysis found that only pre-operative tumor size significantly predicted poorer facial nerve outcome for patients followed-up for ≥6 and ≥12 months (OR 1.27, 95% CI 1.09-1.49, p < 0.01; OR 1.35, 95% CI 1.10-1.67, P < 0.01, respectively). We found no significant relationship between facial nerve function and age, extent of resection, surgical approach, or tumor size (when extent of resection and surgical approach were included in the regression analysis). Because facial nerve palsy is a debilitating and psychologically devastating condition for the patient, we suggest altering surgical aggressiveness in patients with unfavorable tumor anatomy, particularly in cases with large tumors where overaggressive resection might subject the patient to unwarranted risk. Residual disease can be followed and controlled with radiosurgery if interval growth is noted.

Meralgia parestésica: a propósito de una serie de 140 casos / Meralgia Paraesthetca: a report on a series of 140 cases

Introducción. La meralgia parestésica es una patología frecuente en la consulta de neurología extrahospitalaria. Apesar de ello, el diagnóstico, tratamiento y pronóstico de este cuadro no están bien establecidos. Pacientes y métodos. Estudioretrospectivo de 140 pacientes. Se recogen datos demográficos, clínica, estudio diagnóstico, etiología, tratamiento y evolución.Resultados. Hubo un predominio masculino, con una mediana de 54 años. El seguimiento medio fue de 25 meses. Lossíntomas narrados fueron: acorchamiento, dolor urente, hormigueo o pinchazos en el territorio nervioso. En la exploración sehalló hipoestesia como signo más frecuente. Hubo historia de otra neuropatía compresiva en el 13,6%. El diagnóstico se basóen la historia clínica y la exploración neurológica. El estudio neurofisiológico y las pruebas complementarias se reservaronpara casos atípicos. La etiología más frecuente fue la espontánea, y se hallaron sólo tres casos secundarios a lesión estructural.Un tercio de los pacientes recibió tratamiento farmacológico. Aunque el cuadro fue benigno, en la mayoría tendióa cronificarse. Los pacientes tratados farmacológicamente no mostraron una mejoría significativa frente a los que no recibierontratamiento. El dato pronóstico más importante para la mejoría del cuadro fue la identificación y corrección de los factoresdesencadenantes de compresión del nervio. Conclusiones. La meralgia parestésica es una patología frecuente, benigna,pero con tendencia a cronificarse, en la que es importante identificar y corregir factores mecánicos, con pobre respuesta altratamiento farmacológico, y sólo en casos excepcionales secundaria a lesión estructural (AU)

Introduction. Meralgia paraesthetica is a pathology that is frequently seen in visits to extra-hospital neurologyservices. Nevertheless, the diagnosis, treatment and prognosis of this condition remain somewhat unclear. Patients andmethods. A retrospective study was conducted involving 140 patients. Data were collected concerning demographic aspects,clinical picture, diagnostic study, aetiology, treatment and progression. Results. There was a predominance of males, with amean age of 54 years. The mean follow-up time was 25 months. The symptoms that were reported were as follows: numbness,burning pain, tingling or prickling in the nerve territory. Hypaesthesia was the most frequent sign found in the examination.History of another compressive neuropathy was present in 13.6% of patients. The diagnosis was based on the patient recordand the neurological examination. The neurophysiological study and complementary tests were reserved for atypical cases. Themost common causation was spontaneous and only three cases were found to be secondary to a structural lesion. A third of thepatients were receiving pharmacological treatment. Although the clinical picture was benign, in most cases it tended to becomechronic. Patients treated pharmacologically did not show a significant improvement in comparison to those who were not giventreatment. The most important data for forecasting improvement of the clinical picture were the identification and correction ofthe factors precipitating compression of the nerve. Conclusions. Meralgia paraesthetica is a frequent, benign pathology butwith a tendency to become chronic that responds poorly to pharmacological treatment. It is important to identify and correctmechanical factors and only in exceptional cases is it secondary to a structural lesion. (AU)

Techniques for dissection of the facial nerve in benign parotid surgery: a cross specialty survey of oral and maxillofacial and ear nose and throat surgeons in the UK.

We investigated techniques of dissection of the facial nerve currently being used in parotid surgery for benign disease in oral and maxillofacial (OMF) and ear, nose and throat (ENT) surgery. A postal questionnaire was sent to 300 OMF and 300 ENT consultants and 49% were returned(171(57%) OMF and 123 (41%) ENT. The antegrade technique was used routinely by 209 surgeons (87%), the retrograde technique by 9 (4%), and both techniques combined by 21 surgeons (9%). The antegrade technique was used by 135 surgeons (56%) for revision parotidectomy, by 193 (81%) for limited superficial parotidectomy, by 173 (72%) for obese patients with large tumours and by 75 (31%) for injury to the facial nerve. The retrograde technique was used by 21 surgeons (9%) for revision parotidectomy, by 22 (9%) for limited superficial parotidectomy, by 15 (6%) for obese patients with large tumours and by 29 surgeons (12%) for injury to the facial nerve. A combination of techniques was chosen by 83 surgeons (35%) in revision parotidectomy, by 24 surgeons (10%) in limited superficial parotidectomy, by 51 surgeons (21%) in obese patients with large tumours and by (56%) surgeons 135 for injury to the facial nerve.

The influence of prophylactic vasoactive treatment on cochlear and facial nerve functions after vestibular schwannoma surgery: a prospective and open-label randomized pilot study.

OBJECTIVE: Facial nerve paresis and hearing loss are common complications after vestibular schwannoma surgery. Experiments with facial nerves of the rat and retrospectively analyzed clinical studies showed a beneficial effect of vasoactive treatment on the preservation of facial and cochlear nerve functions. This prospective and open-label randomized pilot study is the first study of a prophylactic vasoactive treatment in vestibular schwannoma surgery. METHODS: Thirty patients were randomized before surgery. One group (n = 14) received a vasoactive prophylaxis consisting of nimodipine and hydroxyethylstarch which was started the day before surgery and was continued until the seventh postoperative day. The other group (n = 16) did not receive preoperative medication. Intraoperative monitoring, including acoustic evoked potentials and continuous facial electromyelograms, was applied to all patients. However, when electrophysiological signs of a deterioration of facial or cochlear nerve function were detected in the group of patients without medication, vasoactive treatment was started immediately. Cochlear and facial nerve function were documented preoperatively, during the first 7 days postoperatively, and again after long-term observation. RESULTS: Despite the limited number of patients, our results were significant using the Fisher's exact test (small no. of patients) for a better outcome after vestibular schwannoma surgery for both hearing (P = 0.041) and facial nerve (P = 0.045) preservation in the group of patients who received a prophylactic vasoactive treatment. CONCLUSION: Prophylactic vasoactive treatment consisting of nimodipine and hydroxyethylstarch shows significantly better results concerning preservation of the facial and cochlear nerve function in vestibular schwannoma surgery. The prophylactic use is also superior to intraoperative vasoactive treatment.

Management of neuropathic orofacial pain.

Current management of painful trigeminal neuropathies relies on pharmacological (topical and systemic), surgical, and complementary modalities. There is, however, a lack of quality research relating to the effectiveness of these modalities. In this review we analyze the available data that relates to the therapy of trigeminal neuralgia, postherpetic neuralgia, and posttraumatic neuropathies and provide clinical guidelines. The review focuses on medical management, as well as surgical and other interventions for painful neuropathies.

Staged resection of large acoustic neuromas.

OBJECTIVE: Surgical removal of large (>3 cm) acoustic neuromas is associated with poor long-term facial nerve function results and higher complication rates. This study analyzes whether long term facial nerve function and the incidence of neurological and vascular complications is improved by resection of large acoustic neuromas in 2 or 3 stages. PATIENTS AND METHODS: Among 660 patients who underwent surgical resection of acoustic neuromas between 1989 and 2002 by the senior author (J.M.K.), 34 (5%) patients underwent a staged resection of their large-sized tumors: stage I via a retrosigmoid craniotomy and stage II via a translabyrinthine approach. A retrospective chart review was performed. Tumor size, completeness of tumor removal, tumor recurrence, facial nerve function, and any complications were noted. RESULTS: The average tumor size was 4.4 cm with a mean postoperative length of follow-up of 6 years after the last surgery. Thirty-one patients underwent a 2-staged resection and 3 patients underwent a 3-staged resection. After their last surgery, 32 (94%) patients had excellent long-term facial function grades of House-Brackmann (H-B) I, one was H-B III, and one was H-B VI. All patients had a total or near-total (>98%) resection. There were no tumor recurrences on follow-up MRI scans. From these 71 operations, no patients required reoperation for a CSF leak. There were no deaths, strokes, hydrocephalus, or meningitis. CONCLUSION: In conjunction with the reported technical refinements, staged resection of large tumors significantly reduces morbidity and improves long-term facial nerve function. EBM RATING: C.

Malignant tumours of the parotid gland: a 12-year review.

Malignant parotid tumours are uncommon and present a significant management challenge. Fifty-one such patients (25 male, 26 female, median age 64 years) operated on in the Newcastle Plastic Surgery Unit between 1983 and 1994 were retrospectively evaluated. Preoperative investigations included FNA cytology (n = 20), and for staging CT and/or MRI scans (n = 21). Of the 35 primary tumours 32 were epithelial and three lymphomatous. Metastatic tumours were squamous cell carcinoma (7), melanoma (6), renal cell carcinoma (2) and sebaceous carcinoma (1). FNA cytology correctly diagnosed malignancy with an 88% sensitivity (false negatives = 2). A total or radical parotidectomy was required in 60% of patients, the rest undergoing superficial parotidectomy. In continuity neck dissection was undertaken in 23 (45%) cases. Postparotidectomy reconstruction included 10 free, 3 myocutaneous, and 4 local transposition/rotation flaps. Thirty-seven patients (73%) received postoperative radiotherapy. Seventy-two per cent of patients are alive after a mean follow-up of 42 months. The crude 5- and 10-year survival rates were 68% and 49% respectively while the loco-regional control rate (Kaplan-Meier method) at 10 years was 79%. Fifteen patients (30%) have permanent facial palsy. It is concluded that radical surgery with appropriate reconstruction followed by planned postoperative adjuvant radiotherapy gives effective control of malignant parotid tumours.

Operative management of acoustic neuromas: the priority of neurologic function over complete resection.

The objective of surgical management of acoustic tumors is to remove them entirely and preserve facial nerve function and hearing when possible. A dilemma arises when it is not possible to remove the entire tumor without incurring additional neurologic deficits. Twenty patients who underwent intentional incomplete surgical removal of an acoustic neuroma to avoid further neurologic deficit were retrospectively reviewed. They were divided into a subtotal group (resection of less than 95% of tumor) and a near-total group (resection of 95% or more of tumor) and were followed yearly with either computed tomography or magnetic resonance imaging. The subtotal group was planned and consisted of elderly patients (mean age, 68.5 years) with large tumors (mean, 3.1 cm). The near-total group consisted of younger patients (mean age, 45.8 years) and smaller tumors (mean, 2.3 cm). The mean length of followup for all patients was 5.0 years. Ninety percent of patients had House grade I or II facial function post-operatively. Radiologically detectable tumor regrowth occurred in only one patient, who was in the subtotal resection group. Near-total resection of acoustic tumor was not associated with radiologic evidence of regrowth of tumor for the period of observation. Within the limits of the follow-up period of this study, subtotal resection of acoustic neuroma in elderly patients was not associated with clinically significant recurrence in most patients and produced highly satisfactory rates of facial preservation with low surgical morbidity.

Management of seventh and eighth nerve involvement by cerebellopontine angle tumors.

Microsurgical techniques have made a significant contribution in the advancement of surgery. Since then, the field of neurosurgery has made great and rapid strides. Neurosurgeons now venture through the deep and delicate regions of the brain where they dared not venture only a few years ago. In particular, the morbidity and mortality of surgery in the CPA has seen a progressive decrease. This presentation deals with 200 consecutive tumors in the CPA operated on using microsurgical techniques during the last 6 years. One hundred sixty-seven (83.5%) of them were acoustic neuromas (which included 12 patients with bilateral tumors). Of the remaining 33, there were 21 meningiomas, 10 epidermoids, and 2 angioblastomas. Preoperative investigation has been aimed at arriving at a diagnosis which is as exact as possible in order to plan the operative strategy. All patients, ranging in age from 16 to 84, have been operated upon in the lounging position (with the necessary precautions) through a unilateral suboccipital craniectomy. The basic surgical technique, irrespective of the tumor, is to decompress it from within in order to relieve its tension and pressure on surrounding nerves, vessels, and the brain stem. The structures which are only compressed are spontaneously relieved of compression. This helps define their full anatomic course. Having been identified, they are protected from damage. The most adherent points between tumor and nerves are recognized and handled last under direct vision when there is sufficient space to allow manipulation of the tumor. In the rare event of the facial nerve being interrupted, nerve graft procedures are attempted during the same operation. Our experience with the technique of intracranial-intratemporal facial nerve grafting has yielded excellent results. The cochlear nerve lacks a Schwann cell cover in the CPA and is more prone to being affected, either by tumor processes or surgical manipulation. Of our 167 acoustic nerve tumors, 60% were larger than 3 cm in diameter. The two important factors with regard to predicting the preservation of the seventh and eighth cranial nerves are tumor size (less than 3 cm) and preoperative hearing loss (less than 40 dB). The preservation of facial nerve function after tumor removal was achieved in 87.8% of patients. The facial nerve was preserved in all patients with other tumors. With regard to hearing ability the overall result of preservation of function was achieved in 27.6%. However, when a low hearing loss (less than 40 dB) and small tumor size (less than 3 cm) are taken into account, the preservation was as high as 58%.(ABSTRACT TRUNCATED AT 400 WORDS)

Facial nerve preservation during surgery for removal of acoustic nerve tumors.

A series of 33 patients with 35 acoustic nerve tumors is reviewed. Tumor size was estimated from computerized tomography (CT) scans, and its influence on anatomical and functional preservation of the facial nerve was assessed. Six tumors (one invading the petrous bone, three medium and two large tumors) were not detected on CT scans. The translabyrinthine approach was used in seven instances (one small and six medium tumors) and the suboccipital transmeatal approach for 28 tumors (seven medium and 21 large tumors). Anatomical preservation of the facial nerve was achieved in 83% of operations for tumor removal, two of which were subtotal. A further two patients underwent subtotal removal, but the facial nerve was destroyed. Large tumors carried an increased risk of damage to the facial nerve, but even in this group the nerve was preserved anatomically intact in 70% of cases. Damage to the facial nerve occurred more frequently in patients with preoperative evidence of facial weakness; however, this factor did not appear to influence functional recovery of the facial nerve, provided that the nerve was intact at the end of the operation. A simple grading system for facial nerve function is described. Ony 76% of anatomically intact facial nerves showed any evidence of function 1 month after surgery. Postoperatively, facial function improved with time. At the latest review, 45% of these patients had normal facial function or mild facial weakness (Grades I and II).

Technical and instrumental improvements in the surgical treatment of acoustic neurinomas.

Microsurgical removal of large acoustic neurinomas, more than 3 cm in diameter, has been performed by the lateral suboccipital transmeatal approach with the patient in the lateral position in 68 cases in the past 5 years. sixty-two patients (92%) returned to their former occupations and two died: one in the immediate postoperative period and the other 16 months later. The postoperative follow-up examination showed satisfactory facial nerve function in 70% of the patients. Hearing was preserved in six of 14 patients who had preoperatively retained their auditory function. The authors emphasize the usefulness of bipolar forceps for intraoperative stimulation of the facial nerve and for facial muscle monitoring. The value of the four-pronged hook and the multipurpose head-frame in this procedure is also discussed.