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Infusion Misdirection in Microincisional Vitrectomy Surgery
Edwin H Ryan1, Lawrence S Halperin2, Robert A Mittra1
1VitreoRetinal Surgery, P.A., Minneapolis, Minnesota.
Purpose:
To review the incidence and possible mechanisms of 2 problems caused by infusion misdirection during microincisional vitrectomy in 1 physician's practice and to find an estimate of the broader occurrence among other physicians.
Design:
Observational series of 1 surgeon's cases over 2 periods. A survey also was sent to other retinal specialists.
Participants:
Patients undergoing microincisional vitrectomy.
Methods:
The physician tracked the occurrence of intraoperative hypotony and unintentional anterior chamber air infusion in his practice. A survey was sent to 2000 members of the American Society of Retina Specialists and the Retina Society.
Main Outcome Measures:
Primary outcome measure was the incidence of hypotony during microincisional vitrectomy, defined as softening of the globe to the point of corneal or scleral infolding, or both, that resolved with repositioning of the infusion cannula. The secondary outcome measure was incidence of unplanned air flow into the anterior chamber. Survey questions included frequency of observed infusion interruption and incidence of inadvertent anterior chamber air infusion.
Results:
In the earlier series, of 232 vitrectomies, 37 (16%) showed signs of episodic hypotony after infusion blockage. Seven cases (3%) showed inadvertent air flow into the anterior chamber. One hundred fifty-two physicians responded to the survey. Fifty-seven percent reported infusion blockage and hypotony in 1% to 5% of cases. Fifty-nine percent reported air flow into the anterior chamber in some cases. In the later series, 12 instances of infusion blockage were noted in 118 cases. Awareness of the issue and additional attention to the infusion line taping did not prevent the problem from occurring. In the survey, most respondents reported observing both infusion interruption and inadvertent anterior chamber air infusion on occasion.
Conclusions:
Infusion misdirection resulting in hypotony or air flow into the anterior chamber seems to be infrequent, but it remains a risk. Awareness of the problem reduces the incidence, but does not eliminate it. The potential inadvertently to touch the retina, choroid, or lens increases when these events occur. Infusion misdirection can be avoided by maintaining the correct position of the cannula, which may be facilitated by an external support to the tubing.
Insights
Infusion misdirection during microincisional vitrectomy can cause hypotony and air infusion, though infrequent. Awareness helps, but risks remain, necessitating careful cannula positioning.
Area of Science:
- Ophthalmology
- Surgical Techniques
Background:
- Microincisional vitrectomy is a common surgical procedure.
- Infusion misdirection is a potential complication during vitrectomy.
Purpose of the Study:
- To review the incidence and mechanisms of infusion misdirection during microincisional vitrectomy.
- To estimate the broader occurrence of these issues among other surgeons.
Main Methods:
- Observational series of one surgeon's cases over two periods.
- Survey sent to 2000 members of the American Society of Retina Specialists and the Retina Society.
Main Results:
- In the initial series, 16% of vitrectomies showed hypotony and 3% had anterior chamber air infusion.
- Survey results indicated that 57% of respondents reported hypotony in 1-5% of cases, and 59% reported air infusion.
- In the later series, 12 instances of infusion blockage occurred in 118 cases, despite increased awareness.
Conclusions:
- Infusion misdirection is an infrequent but persistent risk during microincisional vitrectomy.
- Awareness of infusion misdirection can reduce but not eliminate its incidence.
- Maintaining correct cannula position, potentially with external tubing support, can help avoid infusion misdirection.
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