Bimanual Dissection Research Articles

Impact of Dynamic Endoscopy and Bimanual-Binarial Dissection in Endoscopic Endonasal Surgery Training: A Laboratory Investigation.

Objective The lack of a standard technique may be a relevant issue in teaching endoscopic endonasal surgery (EES) to novice surgeons. The objective of this article is to compare different endoscope positioning and microsurgical dissection techniques in EES training. Methods A comparative trial was designed to evaluate three techniques: group A, one surgeon performing binarial two-hands dissection using an endoscope holder (rigid endoscopy); group B, two surgeons performing a combined binarial two- and three-handed dissection with one surgeon guiding the endoscope (dynamic endoscopy); and group C, two surgeons performing a binarial two-hands dissection with one surgeon dedicated to endoscope positioning and the other dedicated to a two-handed dissection. Trainees were randomly assigned to these groups and oriented to complete surgical tasks in a validated training model for EES. A global rating scale, and a specific-task checklist for EES were used to assess surgical skills. Results The mean scores of the global rating scale and the specific-task checklist were higher (p = 0.001 and 0.002, respectively) for group C, reflecting the positive impact of dynamic endoscopy and bimanual dissection on training performance. Conclusions We found that dynamic endoscopic and bimanual-binarial microdissection techniques had a significant positive impact on EES training.

The evolution of endoscopic approaches to the lateral cavernous sinus.

The evolution of endoscopic approaches to the lateral cavernous sinus.

The Role of Bimanual Dissection and Dynamic Endoscopy in Endoscopic Neurosurgical Training: Preliminary Results of a Laboratory Investigation

The Role of Bimanual Dissection and Dynamic Endoscopy in Endoscopic Neurosurgical Training: Preliminary Results of a Laboratory Investigation

The Role of Bimanual Dissection and Dynamic Endoscopy in Endoscopic Neurosurgical Training: A Laboratory Investigation

The Role of Bimanual Dissection and Dynamic Endoscopy in Endoscopic Neurosurgical Training: A Laboratory Investigation

Vestibular schwannoma surgery via the retrosigmoid transmeatal approach

Aims of modern vestibular schwannoma surgery are complete tumor resection with functional facial nerve and hearing preservation, if possible. Here we present our technique of bimanual dissection for vestibular schwannoma resection through the retrosigmoid approach. A slightly curved surgical incision is planned two fingers behind the ear extending from the level of the tip of the ear to 1 cm below the mastoid tip. The retrosigmoid craniectomy exposes the sinus knee, the inferior border of the transverse sinus, the medial border of the sigmoid sinus and horizontal segment of the occipital squama. The dura is opened under the microscope in semilunar fashion parallel to the course of the sigmoid sinus. We open the IAC with a high-speed diamond drill from lateral to medial, opening the canal for 180° of its circumference. The intrameatal part of the vestibular schwannoma is partially removed and the facial nerve identified Thereafter, we open the capsule and debulk the tumor with an ultrasonic surgical aspirator in the CPA. Once the tumor's mass is significantly reduced, a bimanual dissection of the cleavage plane between capsule and the surrounding arachnoid is performed. Starting from below, the capsule is elevated with a tumor grasping forceps and the arachnoid membrane is peeled off. Following the cleavage plane, the facial nerve is separated in a medial to lateral direction from the VS's capsule. Throughout the whole procedure the field is irrigated with warm Ringer's solution. We seal the drilled posterior lip of the IAC as well as eventually opened mastoid air cells with a free muscle or fat patch. Vestibular schwannoma surgery through the retrosigmoid approach is a safe procedure that allows gaining good functional results.

Access to the parapharyngeal space: An anatomical study comparing the endoscopic and open approaches

A subtemporal preauricular approach to the infratemporal fossa and parapharyngeal space has been the traditional path to tumors of this region. The morbidity associated with this procedure has lead to the pursuit of less invasive techniques. Endoscopic access using a minimally invasive transmaxillary/transpterygoid approach potentially may obviate the drawbacks associated with open surgery. The anatomy of the parapharyngeal space is complex and critical; therefore, a comparison of the anatomy exposed by these different approaches could aid in the decision making toward a minimally invasive surgical corridor. Technical Note. The parapharyngeal space was accessed endonasally by removal of the medial and posterior walls of the maxillary sinus. To allow better visualization and increased triangulation of a bimanual dissection technique, a sublabial canine fossa antrostomy was created. The medial and lateral pterygoid plates were removed. Further lateral dissection exposed the relevant anatomy of the parapharyngeal space. A subtemporal preauricular infratemporal approach was also completed. The endoscopic approach provided sufficient access to the superior portion of the parapharyngeal space. The open approach also provided adequate access; however, it required a larger surgical window, causing greater injury. A significant advantage of the subtemporal approach is the improved access to the petrous portion of the internal carotid artery. Conversely, the endonasal approach provided improved access to the anterior and medial portions of the superior parapharyngeal space. Endoscopic endonasal access utilizing a transmaxillary/transpterygoid approach provides a sufficient surgical window for tumor extirpation. Utilization of this approach obviates some of the morbidity associated with an open procedure. 5.

Does video-assisted mediastinoscopy have a better lymph node yield and safety profile than conventional mediastinoscopy?

A best evidence topic was written according to a structured protocol. The question addressed was whether video-assisted mediastinoscopy (VAM) has a better lymph node yield and safety profile than the conventional mediastinoscopy (CM). A total of 194 papers were found, using the reported searches, of which five represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Two studies to date have directly compared CM and VAM with respect to lymph node yield, calculated diagnostics performance and complication rate. In both of these, lymph node yield is shown to be higher using VAM with better sensitivity, negative predictive value and accuracy rates. The favourable figures of lymph node sampling are found to be statistically significant in the single study providing such analysis. Complication rates using VAM are low, however, in the one instance where it is reported as higher than CM, the extensive lymph node dissection used in this technique may be a reasonable explanation for this finding. All studies described here exemplify VAM as a safe and useful tool in mediastinal staging, lymph node dissection and tissue diagnosis of mediastinal diseases given its superior visualization of surrounding structures and advantage of bimanual dissection. The future scope for diagnostic and therapeutic indications of cervical mediastinscopy is anticipated with recent advances and new techniques, such as video-assisted mediastinoscopic lymphadenectomy and virtual mediastinscopy.

Endonasal Resection of Pituitary Adenomas: Comparison of Microscopic Speculum-Based Approach Versus Dual-Surgeon Endoscopic Approach

Before February 2008, all TNTS operations performed at our institution were done using a speculum and microscope (SPEC). Subsequently, all were performed using a dual-surgeon endoscopic approach (ENDO). The endoscopic approach has several potential advantages, including improved direct visualization plus less constrained bimanual dissection, thereby facilitating a more complete resection and obviating “blind dissection,” the latter resulting in intraoperative CSF leaks. A potentially negative consequence of more aggressive tumor removal could be a higher incidence of pituitary dysfunction postoperatively.

Combined pars plana vitrectomy and artificial iris diaphragm implant after globe rupture

Retinal detachment (RD) associated with aniridia due to globe rupture (GR) is an uncommon condition with a severe prognosis. Surgical technique must address anterior and posterior segment issues secondary to the altered compartmentalization and increased risk for corneal toxicity. The purpose of this paper is to report a series of GR patients undergoing combined pars plana vitrectomy (PPV) and artificial iris diaphragm (AID) implant for the repair of RD associated to aniridia. The authors retrospectively reviewed 12 consecutive patients operated on by a single surgeon. Surgery consisted of a standard three-port PPV with extensive bimanual dissection of vitreous base and ciliary body membrane and combined AID implant. Office visits included Snellen visual acuity (VA), intraocular pressure measurement, biomicroscopy and indirect ophthalmoscopy. AID prosthesis included aniridic IOLs, Heimann's PMMA and silicone diaphragm. Mean age was 53 years and mean follow-up was 19 months. At the end of follow-up, seven patients gained more than two lines (58.3%), two lost their vision (16.6%) and three were unchanged (25%). Seven patients (58.3%) had a VA better than 20/400 and one (8%) 20/40 vision. Eight patients (66.6%) retained a clear cornea, two (16.6%) had minimal corneal oedema and two (16.6%) corneal decompensation. Implanted prosthesis included two silicone diaphragms, four PMMA diaphragms and six aniridic IOLs. After an average 1.6 operations, the retina was completely attached in six patients (50%), partially attached in four (33.3%) and detached in two (16.6%). RD associated to GR carries a guarded prognosis both due to RD complexity and hypotony. The combined repair of RD and aniridia after GR offers the advantage of addressing all issues at one time allowing correct eye compartmentalization and better tamponade effect. Successful anatomical and functional results can be achieved although multiple surgeries are often needed.

Videoassistierte mediastinoskopische Chirurgie

Introduced in the 1990s, videomediastinoscopes dramatically improved imaging of the mediastinal structures, and made mediastinoscopy more standardized, user-friendly, and accessible to trainees. Not surprisingly they have been replacing conventional mediastinoscopes for routine biopsy and staging procedures. However it was development of the two-bladed spreadable videomediastinoscope by Linder and Dahan that allowed increased exposure, bimanual dissection, and thus the development of new minimally invasive surgical techniques. The best documented method is video-assisted mediastinoscopic lymphadenectomy (VAMLA), which enables extremely accurate staging and definitive mediastinal surgery.

Video-Assisted Mediastinoscopic Lymphadenectomy (VAMLA)

The development of a two-bladed spreadable videomediastinoscope in 1992 allowed increased exposure and bimanual dissection of mediastinal structures. Concurrent with technical progress in mediastinoscopy, neoadjuvant treatment of stage III lung cancer was introduced, and accuracy of pretreatment mediastinal staging became a topic at issue. In this setting, development of a videomediastinoscopic technique for complete mediastinal lymphadenectomy was the obvious thing to do. Video-assisted mediastinoscopic lymphadenectomy (VAMLA) dissection is guided by anatomical landmarks, very similar to open lymphadenectomy. It includes en bloc resection of the right and central compartments and dissection and lymphadenectomy of the left-sided compartments. In a preliminary case-control study of 40 patients, VAMLA technique was standardized and evaluated against open lymphadenectomy. A second study investigated 130 patients with resectable lung cancer and radiographically normal mediastinum who underwent VAMLA and consecutive lung resection with mediastinal reexploration. VAMLA harvested significantly more nodes than open lymphadenectomy. With a mean duration of 54 minutes and a complication rate of 4.6%, VAMLA appeared applicable to clinical routine. We noted a sensitivity of 93.8%, a specificity of 100%, and a false-negative rate of 0.9%. In our experience, VAMLA is a feasible method of mediastinal staging. Its accuracy and radicality can equal open lymphadenectomy. However, VAMLA is minimally invasive and therefore pretherapeutically available. Its advantages might be of interest with neoadjuvant strategies, trials, involved field radiation, video-assisted thoroscopic lobectomy, and left-sided tumors.

Video-Assisted Mediastinoscopic Surgery: Clinical Feasibility and Accuracy of Mediastinal Lymph Node Staging

This study was conducted to assess indications, procedures, complications, and clinical feasibility of video-assisted mediastinoscopic surgery (VAMS). It also assessed the accuracy of mediastinal lymph node staging by video-assisted mediastinoscopic lymphadenectomy (VAMLA) with bimanual dissection through the twin-bladed, expanding Linder-Dahan mediastinoscope. From 2000 to 2004, we documented and assessed 226 consecutive procedures in a prospective database. A total of 144 VAMLAs for the staging of resectable bronchial carcinoma, and 82 less extensive procedures for other indications were performed, combined with extended mediastinoscopy in 72 patients and with mediastinoscopic sonography in 26. Mean operation time was 54.1 minutes for VAMLA and 36.6 minutes for less extensive procedures. We observed nine complications: five recurrent nerve paralyses, one arterial and two venous injuries, and one mediastinitis. The complication rate was 3.98%, which dropped from 5.3% to 2.6% with growing experience. VAMS detected mediastinal lymph node involvement in 61 (32.8%) of 186 patients with bronchial carcinoma (N2, 45; N3, 16). Mediastinal reassessment at open surgery was done in the 130 resected patients and showed for VAMLA a specificity of 93.75%, a sensitivity of 100%, and a false-negative rate of 0.9%. In our institutional practice, VAMS has replaced conventional mediastinoscopy for reasons of extended surgical options, safety, precision, education, documentation, and enhanced accuracy of pretherapeutic mediastinal staging. Mediastinal staging of resectable bronchial carcinoma is done by VAMLA, because the accuracy is equal to open lymphadenectomy and the access to the left paratracheal and tracheobronchial lymph nodes is improved. No increase in the complication rate was observed. Prolonged operation time was due to more extended procedures not possible with conventional mediastinoscopy, like VAMLA.

Vitrectomy for diabetic traction retinal detachment using the multiport illumination system

Objective To examine the visual and anatomic results of bimanual vitrectomy surgery with the multiport illumination system (MIS) in eyes with advanced diabetic traction retinal detachment. Design Retrospective, noncomparative interventional case series. Participants Sixty-seven consecutive eyes in 62 patients having vitrectomy with the MIS. Methods During surgery, the vitreous, the posterior hyaloid membrane, and fibrovascular proliferative tissue were removed by using bimanual dissection made possible by the MIS. Main outcome measures Retinal reattachment rate, visual function, and postoperative complications were compared with previously published series of vitrectomy for diabetic traction retinal detachment. Results With a minimum of 6 months of follow-up, complete retinal reattachment was achieved in 62 eyes (93%), and macular attachment was achieved in all 67 eyes. Vision was stabilized or improved in 51 eyes (72%), and 5/200 vision was achieved in 47 eyes (70%). No unique complications, such as incision-related retinal tears, occurred. Conclusion MIS allows bimanual surgery during vitrectomy for diabetic traction retinal detachment, with good visual and anatomic results.

The experience to use a modified en bloc excision technique in vitrectomy for diabetic traction retinal detachment.

Modified en bloc excision is a technique in which all posterior hyaloid is excised except the portions essential for membrane dissection. Then, bimanual dissection techniques allow excision of retained fibrovascular membrane "en bloc" with hyaloid. In a consecutive series of 16 eyes with diabetic traction retinal detachment treated with this technique, visual acuity of 5/200 or better was obtained in 11 (69%) of the cases, and complete macula reattachment was noted in 14 (87%) of 16 eyes. The final visual acuity was improved in 12 (75%) cases. While this surgical technique allows a higher rate of anatomic success and less postoperative morbidity, visual results remain limited by irreversible alteration in retinal function.

Two shielded 'bullet' probes for panoramic endoillumination.

Panoramic viewing during vitrectomy offers significant advantages over conventional viewing in many cases and is being used with increasing frequency. Two endoillumination probes that reduce the glare occurring with use of the existing panoramic endoillumination probes were developed. They allow easier viewing of the fundus in eyes with poor media and improve the visualization of the vitreous fibers adjacent to the probe in eyes with clear media. One probe is used for endoillumination alone, and the other has a pick to be used for bimanual dissection. The two probes have been used in more than 100 vitrectomies for various indications, and they give excellent illumination with reduced glare.

A Modified En Bloc Excision Technique during Vitrectomy for Diabetic Traction Retinal Detachment: Results and Complications

The visual results and complications were determined for a modified en bloc excision technique for management of diabetic traction macular detachment. A consecutive series of 30 eyes with this condition underwent pars plana vitrectomy, during which all posterior hyaloid except for portions essential for membrane dissection were excised. Bimanual dissection techniques then allowed excision of fibrovascular membranes "en bloc" with the retained hyaloid. After 6 to 44 months of follow-up, visual acuity of 5/200 or better was obtained in 23 (77%) of 30 eyes, with complete reattachment in 29 (97%) of 30 eyes. Iatrogenic retinal breaks occurred in 6 (20%) of 30 eyes. Two eyes required repeat vitrectomy. The modified en bloc excision technique allowed similar visual outcome, a higher reattachment rate, and less postoperative morbidity than previously reported surgical approaches to diabetic traction macular detachment.

Experimental studies for clinical standardization of transabdominal laparoscopic nephrectomy.

In keeping with the maxim that minimal invasiveness is the present working trend in most areas of surgery, we investigated the possibility of laparoscopically removing a diseased human kidney. Before any actual clinical attempt could be made in this direction, an experimental study was set up in order to determine the most beneficial methods and techniques which would guide us through our first clinical cases. This step-by-step training program consists of: (1) initial familiarization with different laparoscopic instruments, bimanual dissection, ligation and coagulation techniques, camera handling and trocar placement as well as organ retrieval systems using the lap simulator; (2) laparoscopic removal of the kidney and ureter of the pig either as short- or long-term study, and (3) laparoscopic simulation with the lap tent during open surgery.

Microscopic Endonasal Surgery for Repair of CSF Leaks

This manuscript will detail our experience using a microscopic endonasal surgery (MES) approach in the repair of spontaneous, traumatic, and/or iatrogenic cerebrospinal fluid (CSF) fistula into the ethmoid and sphenoid sinuses. The location of the fistula in 22 patients was determined by a direct endoscopic or microscopic visualization, intrathecal fluorescein, or computed tomography (CT) with metrizamide. Several of these patients had been treated unsuccessfully with previous neurosurgical, intracranial, and extracranial approaches to stop the leak. The CSF fistulas in all these patients were repaired with a MES approach, packing the leak with either a septal mucosal graft, or abdominal fat and fascia, and no external incisions were utilized. Furthermore, this approach allowed for an overall closure rate of 95% and offered a direct means to locate the fistula at the time of surgery. It also allowed for precise placement of grafts to cover the defect, an opportunity to perform bimanual dissection, and in general afforded an excellent field of vision.

Microscopic Endonasal Surgery: Clinical Update for Treatment of Chronic Sinusitis with Polyps

Microscopic endonasal surgery has been routinely used over the past 5 years in treating over 450 patients with various paranasal sinus pathologic conditions. The main advantages of this technique are wide-field stereoscopic vision, bimanual dissection, and simplified resident instruction. Disadvantages include the need for specialized instrumentation, general anesthesia, and sometimes difficult visualization of angular views. Despite these shortcomings, the precision offered allows for decreased operative morbidity with enhanced preservation of normal tissues. Operative hemorrhage, which often presents a formidable problem during telescopic sinus surgery, is easily controlled by selective bipolar cautery, hypotensive anesthesia, and use of the semi-Fowler's position, which allows blood and mucus to flow out of the operative field. The aim of this manuscript is to detail our operative experience in a group of 325 patients who were treated for chronic sinusitis with polyposis nasi using microscopic endonasal surgery.

Illuminated Retinal Picks for Vitreous Surgery

We developed a new illuminated disposable retinal pick system for use in vitreoretinal surgery. These instruments facilitate bimanual dissection of proliferative tissue while allowing ocular endoillumination. We have found these instruments to be helpful in the management of complicated retinal detachment due to proliferative diabetic retinopathy or proliferative vitreoretinopathy.