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Bimanual irrigation and aspiration with no instrument exchange

¹Lee Eye Centre, Malaysia
²Singapore National Eye Centre

Correspondence: Dr MW Lee
Singapore National Eye Centre
11, Third Hospital Avenue
Singapore 168751
Tel: (65) 98315618
Email: munwailee{at}gmail.com

Date of acceptance: 12th May 2006

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Introduction

Conventionally, irrigation and aspiration (I&A) after co-axial phacoemuslification is done with a single automated handpiece with or without interchangeable bent or curved tips to access subincisional cortex. Even in the best of hands, the subincisional cortex can sometimes be difficult to manage because of poor visibility from distortion of the cornea whilst "reaching" under the incision, the iris and the capsulorhexis margin. Excessive manipulation and repeated excursions in and out of the eye (for change of tips) could also result in undesirable corneal oedema and descemet membrane folds or even detachment. Also, maintenance of the anterior chamber (AC) is difficult and inconsistent due to excessive manipulation and distension of the wound.

Modifications and developments of new instruments[1] have been helpful but the consistent problem with access to subincisional cortex and AC maintenance have not really been addressed until the bimanual technique[2] was introduced. This technique which involves separate aspiration and irrigation cannulas offers much better visibility and accessibility to subincisional cortex as well as a stable AC. However, the bifurcation of the irrigation and aspiration functions would require the creation of an additional paracentesis and the surgeon would have to �swap hands� to change the �angle of attack� in order to complete cortex removal. We would like to introduce a method of bimanual I&A which uses the two existing ports in the eye and eliminates the need for instrument exchange.

Technique

Phacoemulsification is carried out through a 2.75mm biplanar temporal clear corneal incision. The side port is fashioned with a 19G needle 90 degrees to the main section. Irrigation and aspiration is carried out with the normal I&A handpiece through the main section and a �mini-nook� aspirator through the side port. Aspiration of cortex is begun in the quadrant opposite the main handpiece and switching to the side port aspirator is achieved by getting the assistant to turn the three-way tap to allow aspiration flow through the side port cannula. Irrigation is always through the main handpiece. The surgeon can alternately switch back and forth to remove all subincisional cortex.
The most important feature of this setup is the use of two interconnected 3-way taps. Two 3-way taps are used because an additional port then becomes available which could be used to flush the system should it be necessary. Alternating aspiration can be easily achieved by getting the assistant to turn the tap in the appropriate direction.

Discussion

There are many advantages to the bimanual technique of I&A, the most significant being the easy access to subincisional cortex and the ability to maintain AC stability. In conventional I&A, there can be excessive fluctuations in AC depth created during instrument manipulation particularly when reaching for subincisional cortex. This can lead to accidental entrapment of the PC in the aspiration port and subsequently PC rupture. With the bimanual technique, these fluctuations occur less frequently and there is less PC movement or oscillation. This is especially important in cases where there is an unstable PC and in the presence of PC rupture, it can help the surgeon to avoid vitreous[3]. The sideport cannula can also be used to stabilise the globe, retract iris for better visualisation in small pupils and also to tease denser cortex or epinucleus into the port of the main I&A handpiece.
The usual bimanual I&A technique requires another paracentesis and in addition to the main corneal section, there would then be 3 ports. In our experience, however, we have found that bimanual I&A could be just as adequately carried out through the main section and a single paracentesis; hence, only 2 ports are required. Our main section is fashioned with a 2.75mm keratome and there is a snug fit of the main I&A handpiece through this. The side port paracentesis is fashioned with a 19G needle and we observe no excessive AC fluctuations from fluid loss through either of these sites.
Instrument exchange during any intraocular surgery should be kept to the absolute minimum. Not only does excessive instrument exchange prolong the procedure but by repeatedly going in and out of the eye, we could be inadvertently increasing the infectious risk to the eye. Also, repeated trauma to the wound with each entry (or exit) could result in corneal oedema, descemet membrane folds (or detachment) and a less water tight wound. This may then require suturing (hence, prolonging the operation again) or if not sutured, could result in hypotony or again become a potential source of infection.
We believe that bimanual I&A has significant advantages over its conventional counterpart particularly in complicated cases where anterior chamber stability is important. Our technique allows for safe and efficient cortical cleanup without the need to create an additional paracentesis and it can be very easily adopted with the use of simple, cheap and readily available equipment.

Conflict of Interest Statement

Meeting Presentation: This paper has been presented at the 2005 ISRS/AAO meeting in Hong Kong. Financial support: No financial support was received for this paper. Proprietary Interests: The authors have no proprietary interests in the equipment described in this paper.

References

• Horiguchi M. Instrumentation for superior cortex removal. Arch Ophthalmol. 1991;109:1170-1171.
• Colvard, DMC. Bimanual technique to manage subincisional cortical material. J Cataract Refract Surg 1997; 23(5):707-709.
• Brauweiler P. Bimanual irrigation/aspiration. J Cataract Refract Surg. 1996;22:1013-1016