Name: a novel technique of rescuing capsulorhexis radial tear-out using a cystotome
Uploaded: 2011-01-16T16:10:00
Description: Watch this Scientific Journal Video about A Novel Technique of Rescuing Capsulorhexis Radial Tear-out using a Cystotome at JoVE.com

We would like to thank Dr. Wael El Gendy, for video clip, Dr Clemens Wagner from VR magic for his moral support. Authors personal funding.

1. Purpose
To demonstrate a capsulorhexis radial tear out rescue technique using a cystotome on a virtual reality cataract surgery simulator and in a human eye.
2. Method
When a capsulorhexis begins to veer radially towards the periphery beyond the pupillary margin the following steps should be applied without delay.
<ol>
 <li>Stop further capsulorhexis manoeuvre and reassess the situation.</li>
 <li>Fill the anterior chamber ...

<ol>
	<li>Little, B. C., Smith, J. H., Packer, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> J Cataract Refract Surg. 32 (9), 1420-1422 (2006).</li><li>Neuhann, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Theorie+und+Operationstechnik+der+Kapsulorhexis.">Theorie und Operationstechnik der Kapsulorhexis.</a> Klin Monatsbl Augenheilkd. 190, 542-545 (1987).</li><li>Gimbel, H. V., Neuhann, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development,+advantages+and+methods+of+the+continuous+circular+capsulorhexis+technique.">Development, advantages and methods of the continuous circular capsulorhexis technique.</a> J Cataract Refract Surg. 16, 31-37 (1990).</li><li>Gimbel, H. V., Neuhann, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Continuous+curvilinear+capsulorhexis.+(letter).">Continuous curvilinear capsulorhexis. (letter).</a> J Cataract Refract Sur. 17, 110-111 (1991).</li><li>Gimbel, H. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolving+techniques+of+cataract+surgery:+continuous+curvilinear+capsulorhexis,+down-slope+sculpting,+and+nucleofractis.">Evolving techniques of cataract surgery: continuous curvilinear capsulorhexis, down-slope sculpting, and nucleofractis.</a> Semin Ophthalmol. 7, 193-207 (1992).</li></ol>

The EYESI Surgical Simulator is a realistic training platform for surgeons to practice complex capsulorhexis tear-out techniques. Capsulorhexis is the most important and complex part of phacoemulsification and endocapsular intraocular lens implantation procedure. A successful cataract surgery depends on achieving a good capsulorhexis. During capsulorhexis, surgeons may face a challenging situation like a capsulorhexis radial tear-out. A surgeon must learn to tackle the problem promptly without making the situation worse....

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a novel technique of rescuing capsulorhexis radial tear-out using a cystotome

Part 1 : Purpose: To demonstrate a capsulorhexis radial tear out rescue technique using a cystotome on a virtual reality cataract surgery simulator and in a human eye. Part 2 : Method: Steps: When a capsulorhexis begins to veer radially towards the periphery beyond the pupillary margin the following steps should be applied without delay. 2.1) Stop further capsulorhexis manoeuvre and reassess the situation. 2.2) Fill the anterior chamber with ophthalmic viscosurgical device (OVD). We recommend mounting the cystotome to a syringe containing OVD so that the anterior chamber can be reinflated rapidly. 2.3) The capsulorhexis flap is then left unfolded on the lens surface. 2.4) The cystotome tip is tilted horizontally to avoid cutting or puncturing the flap and is engaged on the flap near the leading edge of the tear but not too close to the point of tear. 2.5) Gently push or pull the leading edge of tear opposite to the direction of tear. 2.6) The leading tearing edge will start to do a 'U-Turn'. Maintain the tension on the flap until the tearing edge returns to the desired trajectory. Part 3 : Results: Using our technique, a surgeon can respond instantly to radial tear out without having to change surgical instruments. Changing surgical instruments at this critical stage runs a risk of further radial tear due to sudden shallowing of anterior chamber as a result of forward pressure from the vitreous. Our technique also has the advantage of reducing corneal wound distortion and subsequent anterior chamber collapse. Part 4 : Discussion The EYESI Surgical Simulator is a realistic training platform for surgeons to practice complex capsulorhexis tear-out techniques. Capsulorhexis is the most important and complex part of phacoemulsification and endocapsular intraocular lens implantation procedure. A successful cataract surgery depends on achieving a good capsulorhexis. During capsulorhexis, surgeons may face a challenging situation like a capsulorhexis radial tear-out. A surgeon must learn to tackle the problem promptly without making the situation worse. Some other methods of rescuing the situation have been described using a capsulorhexis forceps. However, we believe our method is quicker, more effective and easier to manipulate as demonstrated on the EYESi surgical simulator and on a human eye. Acknowledgments: List acknowledgements and funding sources. We would like to thank Dr. Wael El Gendy, for video clip. Disclosures: describe potential conflicting interests or state We have nothing to disclose. References: 1. Brian C. Little, Jennifer H. Smith, Mark Packer. J Cataract Refract Surg 2006; 32:1420 1422, Issue-9. 2. Neuhann T. Theorie und Operationstechnik der Kapsulorhexis. Klin Monatsbl Augenheilkd. 1987; 1990: 542-545. 3. Gimbel HV, Neuhann T. Development, advantages and methods of the continuous circular capsulorhexis technique. J Cataract Refract Surg. 1990; 16: 31-37. 4. Gimbel HV, Neuhann T. Continuous curvilinear capsulorhexis. (letter) J Cataract Refract Sur. 1991; 17: 110-111.

Watch this Scientific Journal Video about A Novel Technique of Rescuing Capsulorhexis Radial Tear-out using a Cystotome at JoVE.com

A Novel Technique of Rescuing Capsulorhexis Radial Tear-out using a Cystotome

Capsulorhexis is an important step in phacoemulsification surgery. A surgeon creates a continous curvilinear tear on the anterior lens capsule by controlling the tearing vector forces. A peripherally extended tear is a serious complication. This video demonstrates a novel technique of rescuing capsular radial tear out using a cystotome.

Part 1 : Purpose:   To demonstrate a capsulorhexis radial tear out rescue technique using a cystotome on a virtual reality cataract surgery simulator and ...

a-novel-technique-rescuing-capsulorhexis-radial-tear-out-using

Research

JoVE Journal

Medicine

A Novel Rescue Technique for Difficult Intubation and Difficult Ventilation

We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which works especially well with poor mask fit.
Can not intubate, can not ventilate" (CICV) is a potentially life threatening situation. In this video we present a simulation of the technique we used in a case of CICV where oxygenation and ventilation were maintained by inserting an endotracheal tube (ETT) nasally down to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.
A 13 year old patient was taken to the operating room for incision and drainage of a neck abcess and direct laryngobronchoscopy. After preoxygenation, anesthesia was induced intravenously. Mask ventilation was found to be extremely difficult because of the swelling of the soft tissue. The face mask could not fit properly on the face due to significant facial swelling as well. A direct laryngoscopy was attempted with no visualization of the larynx. Oxygen saturation was difficult to maintain, with saturations falling to 80%. In order to oxygenate and ventilate the patient, an endotracheal tube was then inserted nasally after nasal spray with nasal decongestant and lubricant. The tube was pushed gently and blindly into the hypopharynx. The mouth and nose of the patient were sealed by hand and positive pressure ventilation was possible with 100% O2 with good oxygen saturation during that period of time. Once the patient was stable and well sedated, a rigid bronchoscope was introduced by the otolaryngologist showing extensive subglottic and epiglottic edema, and a mass effect from the abscess, contributing to the airway compromise. The airway was secured with an ETT tube by the otolaryngologist.This video will show a simulation of the technique on a patient undergoing general anesthesia for dental restorations.

We describe a technique to maintain oxygenation and ventilation using an endotracheal tube inserted nasally to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.

We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which ...

A Novel Capsulorhexis Technique Using Shearing Forces with Cystotome

Purpose:
To demonstrate a capsulorhexis technique using predominantly shearing forces with a cystotome on a virtual reality simulator and on a human eye.
Method:
Our technique involves creating the initial anterior capsular tear with a cystotome to raise a flap. The flap left unfolded on the lens surface. The cystotome tip is tilted horizontally and is engaged on the flap near the leading edge of the tear. The cystotome is moved in a circular fashion to direct the vector forces. The loose flap is constantly swept towards the centre so that it does not obscure the view on the tearing edge.
Results:
Our technique has the advantage of reducing corneal wound distortion and subsequent anterior chamber collapse. The capsulorhexis flap is moved away from the tear leading edge allowing better visualisation of the direction of tear. This technique offers superior control of the capsulorhexis by allowing the surgeon to change the direction of the tear to achieve the desired capsulorhexis size.
Conclusions:
The EYESI Surgical Simulator is a realistic training platform for surgeons to practice complex capsulorhexis techniques. The shearing forces technique is a suitable alternative and in some cases a far better technique in achieving the desired capsulorhexis.

This video demonstrates a novel capsulorhexis technique in modern cataract surgery. Capsulorhexis is the most difficult and important part of phacoemulsification surgery.

Purpose:
To demonstrate a capsulorhexis technique using predominantly shearing forces with a cystotome on a virtual reality simulator and on a human eye....

Corneal Confocal Microscopy: A Novel Non-invasive Technique to Quantify Small Fibre Pathology in Peripheral Neuropathies

The accurate quantification of peripheral neuropathy is important to define at risk patients, anticipate deterioration, and assess new therapies. Conventional methods assess neurological deficits and electrophysiology and quantitative sensory testing quantifies functional alterations to detect neuropathy. However, the earliest damage appears to be to the small fibres and yet these tests primarily assess large fibre dysfunction and have a limited ability to demonstrate regeneration and repair. The only techniques which allow a direct examination of unmyelinated nerve fibre damage and repair are sural nerve biopsy with electron microscopy and skin-punch biopsy. However, both are invasive procedures and require lengthy laboratory procedures and considerable expertise. Corneal Confocal microscopy is a non-invasive clinical technique which provides in-vivo imaging of corneal nerve fibres. We have demonstrated early nerve damage, which precedes loss of intraepidermal nerve fibres in skin biopsies together with stratification of neuropathic severity and repair following pancreas transplantation in diabetic patients. We have also demonstrated nerve damage in idiopathic small fibre neuropathy and Fabry's disease.

Corneal Confocal microscopy is a non-invasive clinical technique which may be used to quantify C fibre damage to diagnose and stratify patients with increasing neuropathic severity.

The accurate quantification of peripheral neuropathy is important to define at risk patients, anticipate deterioration, and assess new therapies. ...

A Novel Application of Musculoskeletal Ultrasound Imaging

Ultrasound is an attractive modality for imaging muscle and tendon motion during dynamic tasks and can provide a complementary methodological approach for biomechanical studies in a clinical or laboratory setting. Towards this goal, methods for quantification of muscle kinematics from ultrasound imagery are being developed based on image processing. The temporal resolution of these methods is typically not sufficient for highly dynamic tasks, such as drop-landing. We propose a new approach that utilizes a Doppler method for quantifying muscle kinematics. We have developed a novel vector tissue Doppler imaging (vTDI) technique that can be used to measure musculoskeletal contraction velocity, strain and strain rate with sub-millisecond temporal resolution during dynamic activities using ultrasound. The goal of this preliminary study was to investigate the repeatability and potential applicability of the vTDI technique in measuring musculoskeletal velocities during a drop-landing task, in healthy subjects. The vTDI measurements can be performed concurrently with other biomechanical techniques, such as 3D motion capture for joint kinematics and kinetics, electromyography for timing of muscle activation and force plates for ground reaction force. Integration of these complementary techniques could lead to a better understanding of dynamic muscle function and dysfunction underlying the pathogenesis and pathophysiology of musculoskeletal disorders.

We describe a new ultrasound-based vector tissue Doppler imaging technique to measure muscle contraction velocity, strain and strain rate with sub-millisecond temporal resolution during dynamic activities. This approach provides complementary measurements of dynamic muscle function and could lead to a better understanding of mechanisms underlying musculoskeletal disorders.

Ultrasound is an attractive modality for imaging muscle and tendon  motion during dynamic tasks and can provide a complementary methodological  approach ...

Murine Cervical Heart Transplantation Model Using a Modified Cuff Technique

Mouse models are of special interest in research since a wide variety of monoclonal antibodies and commercially defined inbred and knockout strains are available to perform mechanistic in vivo studies. While heart transplantation models using a suture technique were first successfully developed in rats, the translation into an equally widespread used murine equivalent was never achieved due the technical complexity of the microsurgical procedure. In contrast, non-suture cuff techniques, also developed initially in rats, were successfully adapted for use in mice1-3. This technique for revascularization involves two major steps I) everting the recipient vessel over a polyethylene cuff; II) pulling the donor vessel over the formerly everted recipient vessel and holding it in place with a circumferential tie. This ensures a continuity of the endothelial layer, short operating time and very high patency rates4.
Using this technique for vascular anastomosis we performed more than 1,000 cervical heart transplants with an overall success rate of 95%. For arterial inflow the common carotid artery and the proximal aortic arch were anastomosed resulting in a retrograde perfusion of the transplanted heart. For venous drainage the pulmonary artery of the graft was anastomosed with the external jugular vein of the recipient5.
Herein, we provide additional details of this technique to supplement the video.

The murine cervical heart transplantation model is well suited for immunological as well as ischemia reperfusion injury studies. We modified the procedure using a non-suture cuff technique and performed more than 1,000 successful transplants with this approach.
Herein, we provide additional details of this technique to supplement the video.

Mouse models are of special interest in research since a wide variety of monoclonal antibodies and commercially defined inbred and knockout strains are ...

Circumscribed Capsular Infarct Modeling Using a Photothrombotic Technique

Recent increase in the prevalence rate of white matter stroke demands specific research in the field. However, the lack of a pertinent animal model for white matter stroke has hampered research investigations. Here, we describe a novel method for creating a circumscribed capsular infarct that minimizes damage to neighboring gray matter structures. We used pre-surgery neural tracing with adeno-associated virus-green fluorescent protein (AAV-GFP) to identify somatotopic organization of the forelimb area within the internal capsule. The adjustment of light intensity based on different optical properties of gray and white matter contributes to selective destruction of white matter with relative preservation of gray matter. Accurate positioning of optical-neural interface enables destruction of entire forelimb area in the internal capsule, which leads to a marked and persistent motor deficit. Thus, this technique produces highly replicable capsular infarct lesions with a persistent motor deficit. The model will be helpful not only to study white matter stroke (WMS) at the behavioral, circuit, and cellular levels, but also to assess its usefulness for development of new therapeutic and rehabilitative interventions.

This manuscript describes a modeling technique of capsular infarct. Here we utilized a modified photothrombotic technique with low intensity of light after pre-surgery target mapping. Using this technique, we created a circumscribed capsular infarct model with persistent motor impairment.

Recent increase in the prevalence rate of white matter stroke demands specific research in the field. However, the lack of a pertinent animal model for ...

A Detailed Protocol for Perspiration Monitoring Using a Novel, Small, Wireless Device

Perspiration monitoring can be utilized for the detection of certain diseases, such as thermoregulation and mental disorders, particularly when the patients are unaware of such disorders or are having difficulty expressing their symptoms. Until now, several devices for perspiration monitoring have been developed; however, such devices tend to have a relatively large exterior, considerable power consumption, and/or less sensitivity.
Recently, we developed a small, wireless device for perspiration monitoring. The device consists of a temperature/relative humidity (T/RH) sensor, battery-driven small data logger, and silica gel as a desiccant in a small cylindrical exterior. The T/RH sensor is placed between the detection windows (through which the water vapor from the skin enters) and the silica gel. The underlying principle of the perspiration monitoring device is based on Fick&#39;s law of diffusion, which means that water vapor flux from the skin to the silica gel (i.e.&#160;transepidermal water loss and perspiration) can be captured by change in humidity at the T/RH sensor. In addition, a baseline subtraction method was adopted to distinguish perspiration and transepidermal water loss.
As shown in the previous report, the developed device can monitor the perspiration at any sites of the body in an easy, wireless manner. However, detailed methods of how to use the device have not been disclosed yet. In this article, therefore, we would like to show the point-by-point tutorials of how to use the device for perspiration monitoring, by showing the sympathetic activity test with the sympathetic skin response monitoring as an example.

Recently, we developed a small wireless device for perspiration monitoring. In this article, we present detailed protocols on how to use the device for perspiration monitoring with an example of the sympathetic activity test.

Perspiration monitoring can be utilized for the detection of certain diseases, such as thermoregulation and mental disorders, particularly when the ...

Mouse Model for Pancreas Transplantation Using a Modified Cuff Technique

Mouse models have several advantages in transplantation research, including easy handling, a variety of genetically well-defined strains, and the availability of the widest range of molecular probes and reagents to perform in vivo as well as in vitro studies. Based on our experience with various murine transplantation models, we developed a heterotopic pancreas transplantation model in mice with the intent to analyze mechanisms underlying severe ischemia reperfusion injury-associated early graft damage. In contrast to previously described techniques using suture techniques, herein we describe a new procedure using a non-suture cuff technique. 
In recent years, we have performed more than 300 pancreas transplantations in mice with an overall success rate of &gt;90%, a success rate never described before in mouse pancreas transplantation. The backbone of this non-suture cuff technique for graft revascularization consists of two major steps: (I) pulling the recipient vessel over a polyethylene/polyamide cuff and fixing it with a circumferential ligature, and (II) placing the donor vessel over the everted recipient vessel and fixing it with a second circumferential ligature. The resultant continuity of the endothelial layer results in less thrombogenic lesions with high patency rates and, finally, high success rates.
In this model, arterial anastomosis is achieved by pulling the abdominal aorta of the donor graft over the everted common carotid artery of the recipient animal. Venous drainage of the graft is achieved by pulling the portal vein of the graft over the everted external jugular vein of the recipient. This manuscript provides details and crucial steps of the organ recovery and organ implantation procedures, which will allow researchers with microsurgical skills to perform the transplantation successfully in their laboratories.

Among abdominal solid organ transplantation, pancreatic grafts are prone to develop severe ischemia reperfusion injury-associated graft damage, leading eventually to early graft loss. This protocol describes a model of murine pancreas transplantation using a non-suture cuff technique, ideally suited for analyzing these early, deleterious damages.

Mouse models have several advantages in transplantation research, including easy handling, a variety of genetically well-defined strains, and the ...

Minimally Invasive Muscle Embedding (MIME) - A Novel Experimental Technique to Facilitate Donor-Cell-Mediated Myogenesis

Skeletal muscle possesses regenerative capacity due to tissue-resident, muscle-fiber-generating (myogenic) satellite cells (SCs), which can form new muscle fibers under the right conditions. Although SCs can be harvested from muscle tissue and cultured in vitro, the resulting myoblast cells are not very effective in promoting myogenesis when transplanted into host muscle. Surgically exposing the host muscle and grafting segments of donor muscle tissue, or the isolated muscle fibers with their SCs onto host muscle, promotes better myogenesis compared to myoblast transplantation. We have developed a novel technique that we call Minimally Invasive Muscle Embedding (MIME). MIME involves passing a surgical needle through the host muscle, drawing a piece of donor muscle tissue through the needle track, and then leaving the donor tissue embedded in the host muscle so that it may act as a source of SCs for the host muscle. Here we describe in detail the steps involved in performing MIME in an immunodeficient mouse model that expresses a green fluorescent protein (GFP) in all of its cells. Immunodeficiency in the host mouse reduces the risk of immune rejection of the donor tissue, and GFP expression enables easy identification of the host muscle fibers (GFP+) and donor-cell-derived muscle fibers (GFP-). Our pilot data suggest that MIME can be used to implant an extensor digitorum longus (EDL) muscle from a donor mouse into the tibialis anterior (TA) muscle of a host mouse. Our data also suggest that when a myotoxin (barium chloride, BaCl2) is injected into the host muscle after MIME, there is evidence of donor-cell-derived myogenesis in the host muscle, with approximately 5%, 26%, 26% and 43% of the fibers in a single host TA muscle showing no host contribution, minimal host contribution, moderate host contribution, and maximal host contribution, respectively.

Minimally Invasive Muscle Embedding MIME - A Novel Experimental Technique to Facilitate Donor-Cell-Mediated Myogenesis

We describe a novel experimental technique that we call Minimally Invasive Muscle Embedding (MIME), which is based on the evidence that skeletal muscle tissue contains viable myogenic cells that can facilitate donor-cell-mediated myogenesis when implanted into a host muscle.

Skeletal muscle possesses regenerative capacity due to tissue-resident, muscle-fiber-generating (myogenic) satellite cells (SCs), which can form new ...

Cardiopulmonary Bypass in a Mouse Model: A Novel Approach

As prolonged cardiopulmonary bypass becomes more essential during cardiac interventions, an increasing clinical demand arises for procedure optimization and for minimizing organ damage resulting from prolonged extracorporal circulation. The goal of this paper was to demonstrate a fully functional and clinically relevant model of cardiopulmonary bypass in a mouse. We report on the device design, perfusion circuit optimization, and microsurgical techniques. This model is an acute model, which is not compatible with survival due to the need for multiple blood drawings. Because of the range of tools available for mice (e.g., markers, knockouts, etc.), this model will facilitate investigation into the molecular mechanisms of organ damage and the effect of cardiopulmonary bypass in relation to other comorbidities.

This paper describes how to perform cardiopulmonary bypass in mice. This novel model will facilitate the investigation of the molecular mechanisms involved in organ damage.

As prolonged cardiopulmonary bypass becomes more essential during cardiac interventions, an increasing clinical demand arises for procedure optimization ...