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Biomedical subjects

M Caversaccio

Publications and source records attributed to M Caversaccio.

15 recordsLinked to original sources
PubMed2000

Endovascular treatment of acute and subacute hemorrhage in the head and neck.

OBJECTIVE: Acute and subacute hemorrhage in the head and neck often represent a life-threatening situation. The goal of this study is to evaluate the indications for and contributions of endovascular techniques in the diagnosis and management of such severe cases. DESIGN: Seventy-two patients with acute or subacute intractable hemorrhage of the head and neck were treated over a period of 5 years: 2 patients had experienced trauma; in 6 cases the cause of bleeding was iatrogenic; and in 2 patients intraosseous arteriovenous malformations were manifested. Fifteen patients had tumors, 9 of whom had prior radiotherapy. Forty-seven patients presented with epistaxis (41 idiopathic and 6 during anticoagulation therapy). The endovascular therapy was performed using polyvinyl alcohol particles, fibered platinum or electrolytically detachable coils (Guglielmi detachable coils; Target Therapeutics, Fremont, Calif), a stent, glue (Ethibloc; Ethicon GmbH, Norderstedt, Germany, and Histoacryl; B. Braun Melsungen AG, Melsungen, Germany), or with a combination of these different embolic materials. RESULTS: The acute bleeding was successfully controlled in all cases. Fourteen patients (7 with epistaxis, 5 with tumors, and 2 with arteriovenous malformations) had to be embolized more than once before the bleeding could be controlled. The idiopathic, traumatic, iatrogenic, and remaining tumoral cases were treated only once. The long-term morbidity was 1.9%. CONCLUSIONS: Owing to the recent continuous advances in interventional radiologic techniques, it is possible to treat both acute and subacute life-threatening head and neck hemorrhage most efficiently. In many cases the endovascular therapy complements surgery.

Acute Disease↗
PubMed2000

Frameless computer-aided surgery system for revision endoscopic sinus surgery.

To increase the intraoperative safety factor and to acquire anatomic assistance during revision endoscopic sinus surgery (RESS), we used an optical computer-aided surgery (CAS) system that we developed collaboratively in Bern, Switzerland. During 1 year, 25 RESSs were performed with CAS: recurrent polyposis (n = 20), recurrent frontal recess stenosis (n = 3), and recurrent frontal recess stenosis with mucocele (n = 2). These patients were compared with a control group of 10 patients undergoing RESS without CAS. The same surgeon (M.C.) performed all operations, and there were no minor or major complications in either group. The clinical inaccuracy of our system is between 0.5 and 2 mm with paired-point and surface matching. The navigation system is an important aid to surgeons in identifying anatomic landmarks that are typically difficult to visualize in this type of surgery, thus reducing the stress placed on the surgeon.

Endoscopy↗
PubMed2000

Unilateral choanal atresia. A possible indication for computer aided surgery? "A report of two cases".

Choanal atresia (CA) is a congenital obstruction of the posterior nose. Bilateral CA is a paediatric emergency and must be treated surgically in the first few weeks after birth. This is in contrast to unilateral CA, because surgical management can be planned more selectively. Transpalatinal surgery for CA is a safe procedure. The endonasal technique is minimally invasive and less traumatic; however, a major disadvantage is a limited field of vision. Computer aided surgery using images acquired by computer tomography (CT) or magnetic resonance imaging (MRI) is an application that has emerged in the last few years. This application provides an additional safety factor for endoscopic surgery to resolve choanal atresia, especially in cases of another malformation. We report results from two cases of unilateral CA who were surgically managed with Computer aided surgery.

Adolescent↗
PubMed2000

Practical aspects for optimal registration (matching) on the lateral skull base with an optical frameless computer-aided pointer system.

HYPOTHESIS: Paired-point matching and surface matching are highly accurate when used on the lateral skull base with an optical computer-aided surgery system. BACKGROUND: Computer-aided surgery on the lateral skull base can be done with a pointer system or with the microscope. An optical pointer system that uses anatomic landmarks and surface points has been developed in Bern, Switzerland. METHODS: Axial computed tomography of a cadaver skull was performed. The images were processed on a computer workstation. An infrared camera was used. A reference base mounted on the head and a needle pointer, both equipped with light-emitting diodes, were used. Different anatomic landmarks were determined on the computer image of the skull and were compared with the actual anatomic markers taken on the bone or on the skin simulation material, and the target error was defined. In a second step, additional surface points on different regions of the skull were taken, and the inaccuracy from the target was redetermined. RESULTS: The authors found a mean average error in accuracy from the target with paired-point matching alone in the best series of 0.79 mm. Under skin simulation, they found a deterioration with paired-point matching alone but an improvement in accuracy with surface matching. CONCLUSION: For this navigation system, it is recommended that the following five anatomic points be selected for matching of the lateral skull base: the tip of the mastoid, the mastoid foramen, the umbo, the frontozygomatic suture, and the anterior nasal spine. For additional accuracy in clinical situations, surface matching is recommended.

Microscopy↗
PubMed1999

[Objective value of adenotonsillectomy in the child. A prospective study of incidence of tonsillitis, snoring, pulse oximetry and polysomnography and general development before and after adenotonsillectomy].

65 children were analysed prospectively before and after adeno-tonsillectomy to determine the incidence of upper airway infections, snoring and nocturnal obstructive symptoms. The weight and height percentiles were also determined before and after adeno-tonsillectomy. The Oxygen Desaturation Index (ODI) was measured in 27 children suspected of having a sleep apnea syndrome. In six of these children polysomnographic studies were carried out. A statistically significant reduction (p < 0,005) of upper airway infections could be seen six to twelve months after adeno-tonsillectomy. In 25 children (38%), we observed a postoperative weight gain and in eight cases (12%) a height gain. The obstructive symptoms, especially snoring and respiratory apneas, disappeared or were significantly reduced in 90% of the cases after adeno-tonsillectomy. All preoperatively pathological ODI and AHI normalised after the operation (p < 0,005).

Adenoidectomy↗
PubMed1999

The "Bernese" frameless optical computer aided surgery system.

OBJECTIVE: We report on two years of clinical experience with a frameless Computer Aided Surgery system developed in Bern, Switzerland. MATERIAL AND METHODS: Our navigation system is based on a preoperative computer-tomography (CT) scan (without markers) and an intraoperative optical tracking of head movements and of the surgical instruments. Using landmark and surface-based registration, the skull can be accurately correlated to the CT images. The three-dimensional positions of the surgical instruments, as well as the endoscopic images, are displayed in real time on a monitor. RESULTS: In the last two years, 109 computer-aided interventions have been successfully performed: 89 on the anterior skull base/paranasal sinuses, 15 on the lateral skull base, and 5 minimally invasive procedures on other locations in the skull. No complications occurred. The practical accuracy on the cadaver skull is between 0.5 mm and 1.2 mm, and the clinical accuracy is between 0. 5 mm and 2 mm. CONCLUSIONS: Our navigation system has proven its accuracy and usability. Surgeons feel very comfortable with the increased safety provided by the unequivocal identification of important anatomical structures.

Cadaver↗
PubMed1999

[Navigation surgery in diseases of the paranasal sinuses].

BACKGROUND: Since the mid-80s, endonasal sinus surgery has gained significant importance in the treatment of chronic inflammatory sinus disease. Many surgeons have recognized the necessity of developing new methods to increase the safety of this type of surgery. One of the advancements in increasing the safety of endonasal sinus surgery was the development of computer-aided surgical navigation (CAS) systems. METHODS: Since 1996, we have tried several different CAS systems for difficult surgical procedures in sinus and anterior skull base surgery, mainly revision surgery for chronic inflammatory sinusitis and endonasal tumors. During this time, we tried one electromagnetic ("Insta Trak") and two optoelectric systems ("Surgigate" and "Vector Vision"). RESULTS: In our experience, all systems can be used in endonasal sinus surgery; accuracy was satisfactory and varied between 0.1 and 0.5 mm. There were differences with respect to the time of preparation of the system for surgery as well as to the possibility to use different instruments. CONCLUSIONS: Computer-assisted surgical navigation systems today have gained a degree of accuracy which makes them not only suitable but almost necessary, at least for difficult surgical procedures at the anterior skull base, i.e. revision surgery in chronic inflammatory sinus disease. On the long run, these systems will become mandatory for these kinds of procedures. On the other hand, CAS systems cannot substitute thorough anatomical and surgical training.

Computer Systems↗
PubMed1999

Facial nerve function after petrosectomy.

OBJECTIVES: Evaluation of facial nerve function after petrosectomy in a patient series with facial nerve denudation-decompression, forward or backward rerouting, and facial nerve suture and grafting. STUDY DESIGN: Fifty-six patients with petrosectomies performed for 24 benign and 9 malignant tumors of the petrous bone, 13 malignant tumors of the parotid gland or of the infratemporal spaces with infiltration of the petrous bone, 8 traumatic facial nerve disruptions, and 2 osteoradionecroses were retrospectively evaluated with respect to facial nerve function. Sixteen cases involved a partial, 25 a subtotal, and 15 an extended subtotal petrosectomy. METHODS: The treatment of the facial nerve included 15 denudation-compressions, 23 denudation-compressions with rerouting, 4 primary sutures, and 14 nerve grafts. The House-Brackmann grading system was used for facial nerve evaluation. RESULTS: Normal or nearly normal facial nerve function was obtained in facial nerve denudation-decompression with and without rerouting (House-Brackmann Grade I or II) except in cases of malignant tumors and osteoradionecrosis, where preoperative impaired function remained. Satisfactory results were obtained with nerve suturing and nerve grafting after petrous bone fracture (Grade III or IV, in one case practically Grade II) except in a case of late repair 3 years after the trauma (Grade V). Variable results were obtained with nerve grafting in cases with tumor infiltration: Satisfactory results (5 of Grade III or IV) were obtained when the tumor was healed and also when postoperative radiotherapy was applied; poor results were obtained in the case of tumor recurrence (6 of Grade V or VI). CONCLUSIONS: Our results show that petrosectomy with denudation-decompression of the facial nerve with or without rerouting usually results in a normal mimic of the face. When the facial nerve is disrupted by trauma or when the nerve is infiltrated by tumor, early reconstruction with nerve suture or grafting mostly leads to a partial and quite acceptable reinnervation of the face.

Adult↗
PubMed1998

[Otogenic meningitis].

We present three patients with otogenic meningitis, whose illness varied in extent and clinical course. Meningitis and otitis media are associated in 19-22% of all meningitis-patients. Streptococcus pneumoniae is the predominant microorganism with hemophilus influenzae being the second most important. We discuss the importance and problems of spinal puncture, early CT-scan as well as further, more extensive and sophisticated examinations to exclude late complications or predisposing factors. We emphasize an early start of antibiotic treatment, which should not be delayed for diagnostic reasons. With the appearance of highly penicillin-resistant pneumococci antibiotic therapy may become more difficult in the future, but for the moment pneumococcal infections in Switzerland can initially still be treated with cephalosporins or high dose penicillin. The use of steroids, although of unproven efficacy, may be considered in some cases. An otolaryngologist should initially be consulted for diagnostic reasons as well as for possibly indicated early surgery.

Adult↗
PubMed1998

Microsurgical endonasal dacryocystorhinostomy with long-term insertion of bicanalicular silicone tubes.

OBJECTIVE: To assess the results of microsurgical endonasal dacryocystorhinostomy with long-term insertion of single or double bicanalicular silicone tubes in canalicular (presaccal) and ductal (postsaccal) stenosis of the nasolacrimal duct system. DESIGN: Retrospective follow-up of case series between 1992 and 1996. PATIENTS: Thirty-eight patients were included in the study: 19 with ductal stenosis; 28 with canalicular stenosis; and 1 (a 6-month-old girl) with congenital agenesis of the lacrimal duct system. INTERVENTION: Forty-seven endonasal microscopic dacryocystorhinostomies were performed on 38 patients. Bicanalicular silicone tubes were inserted, fixed in the nasal cavity, and left in place as long-term space holders. In patients with canalicular stenosis, a specially designed double bicanalicular tube was inserted for maximal dilatation of the lacrimal canals. The tubes are left in place as long as possible, ie, for months to several years. In cases in which there was recurrent obstruction following accidental tube extrusion, we simply inserted new tubes using a short-acting anesthesia. RESULTS: With 1 procedure, 17 (91%) of the eyes that were surgically treated for ductal stenosis became symptom free. The success rate in the cases of canalicular stenosis was 72%. In the remaining 28% of patients with recurrent obstruction, endonasal revision surgery was performed with new insertion of bicanalicular tubes. With the new tubes in place, these remaining patients have also stayed largely symptom free (length of follow-up, 8 months to 5 years [average, 3 years]). CONCLUSIONS: The routine insertion of bicanalicular tubes as long-term spacers has proved effective and has been tolerated without problems. A new aspect of our study is that in cases of canalicular stenosis or congenital agenesis of the lacrimal duct, which generally have a poor prognosis, the patients also benefit when our specially designed long-term double bicanalicular tubes are inserted in the lacrimal ducts.

Adolescent↗
PubMed1998

[Computer-assisted surgical navigation with a dynamic mobile framework for the nasal fossae, sinuses and base of the skull].

Surgery of the skull base and of the paranasal sinuses is often difficult because of the complex anatomy and the delicate structures; serious complications (loss of vision, cerebral lesion) have been reported. To improve the safety of such operations, computer-assisted navigation surgery is increasingly being put to use. We introduce the system which was developed in Berne. Our computer-assisted system is based on an intraoperative pursuit of the head and instruments which are equipped with infrared diodes and registered by an opto-electronic system-camera. The CT-acquisition of the head is accomplished framelessly without a head-holding device. This allows free movement of the head during surgery. Between March and November 1997, 35 navigation operations were performed for various pathologies at the anterior and lateral skull base. The majority of the cases were endonasal operations. No surgical complications occurred inspite of the complexity of the operations. The measured accuracy of the system between the CT and the actual instrument location in the patient was 0.5-2 mm (mean : < 1 mm) for the anterior skull base and 1-2.5 mm (mean < 1.5 mm) for the lateral skull base. The intraoperative navigation system allows identification of essential anatomical structures and permits safe and efficient surgery without additional loss of time. In addition, such a system allows minimal invasive approaches, and new operations may become possible.

Adult↗
PubMed1996

Descending necrotizing mediastinitis: surgical treatment via clamshell approach.

BACKGROUND: Descending necrotizing mediastinitis requires an early and aggressive surgical approach to reduce the high morbidity and mortality associated with this disease. The clamshell incision has provided excellent exposure of the entire mediastinum and both pleural cavities and was assessed in patients suffering from descending necrotizing mediastinitis. METHODS: Three patients with descending necrotizing mediastinitis and bilateral pleural empyema due to invasive streptococcal infections were operated on with this method. Radical debridement of the mediastinum and bilateral decortication was performed through a clamshell incision, including pericardiectomy in 2 patients. All patients received initially a high dose of antibiotic regimen, 2 had bilateral chest tube drainage, and 1 had mediastinal drainage and pleural debridement via cervical mediastinotomy and thoracoscopy, respectively. All these measures alone, however, failed to control the disease. RESULTS: The clamshell incision offered an excellent exposure for bilateral decortication and debridement of the entire mediastinum including pericardiectomy. One patient, who was referred in critically ill condition, died of multiorgan failure in the postoperative period. The remaining 2 patients recovered without further interventions and without evidence of phrenic nerve palsy, sternum osteomyelitis, or sternal override. CONCLUSIONS: The clamshell approach offers an excellent exposure for a complete one-stage surgical treatment with mediastinal debridement and bilateral decortication in patients suffering from descending necrotizing mediastinitis in the absence of profound septic shock.

Adolescent↗
PubMedDate not supplied

The drainage of cerebrospinal fluid into the lymphatic system of the neck in humans.

A histo- and immunohistochemical examination of the superior deep cervical lymph nodes was performed in a group of 19 patients who died from intracerebral haemorrhage. For comparison two control groups without cerebral lesions were studied (n = 17, n = 13). Free iron deposits as shown within the lymph nodes by Prussian blue reaction were seen significantly more often following intracerebral haemorrhage than without bleeding. The expression of CD 68 (a marker for macrophages) or CR 3/43 (microglia) gave a strong reaction, but there are no significant differences between the three groups. Glial fibrillary acidic protein was rarely seen in the three groups. Raising the CSF pressure results in increased CSF drainage into the cervical lymph nodes. The clinical importance of this lymphatic drainage suggests a communication between the brain and the immune system of the head and neck, with a possible selective up- and down-regulation.

Carcinoma↗
PubMedDate not supplied

[Surgery of the skull base and paranasal sinuses assisted by a computerized navigation system without external orientation support].

OBJECTIVE: To present a new concept in computer-assisted surgery for the base of the skull and paranasal sinuses using a frameless navigation system. METHOD AND MATERIALS: This system is based on computer tomography images, which are displayed online on a workstation monitor. Using specially mounted infrared instruments, the patient's anatomic landmarks are visualized on the monitor. This system does not require invasive markers because it uses a reference system fixed to the patient with a silicone maxillary splint. PATIENTS: From March 1997 to February 1998 we operated on 44 patients with this innovative system. RESULTS: The clinical accuracy of this system was 0.5 to 2 mm for surgery of the anterior skull base and 1 to 2.5 mm for the lateral skull base. There were no intraoperative complications. CONCLUSIONS: This computer-assisted surgical aid made it possible to carry out complex and difficult skull-base surgery with reasonable intraoperative safety. It also allowed development of new minimally invasive surgical approaches.

Chondroma↗