Unexpected cardiovascular collapse from massive air embolism during endoscopic retrograde cholangiopancreatography.

A 72 year-old woman with cholangiocarcinoma presented for endoscopic retrograde cholangio pancreatography (ERCP) for diagnostic intraductal endoscopy under GETA. During the technically difficult procedure the patient became suddenly hypoxic, hypotensive, bradycardic, and progressed to PEA code (ETCO2 5 mmHg). ACLS was initiated. Transesophageal echo demonstrated massive right heart air accumulation; abdominal X-Ray showed air filled bile ducts. Central access was obtained, a pulmonary artery catheter floated, and 30 ml of air aspirated from the RV. Within 5 minutes pulses returned; the patient was transferred to the ICU. MRI revealed two watershed infarcts in the right frontal lobe. The patient fully recovered and returned a month later for an uneventful ERCP.

Outcomes of temporal clear cornea versus superior scleral tunnel phacoemulsification incisions in a university training program.

BACKGROUND AND OBJECTIVES: To evaluate the complication and visual outcomes of residents performing temporal clear cornea (TCC) compared to superior scleral tunnel (SST) phacoemulsification. PATIENTS AND METHODS: We conducted a retrospective analysis of complications and visual outcomes for 534 phacoemulsification procedures done by third-year residents over a five-year period (June 1992-July 1997) at the department of ophthalmology, University of Chicago. All cases were completed using a TCC or SST incision. RESULTS: There was vitreous loss in 6.0% of 348 eyes with TCC incisions and in 11.8% of 186 eyes with SST incisions (P < 0.02). Posterior capsule breaks occurred in 1 1.5% of the TCC group versus 17.7% in the SST group (P < 0.0453). Best corrected visual acuity of 20/40 or better was achieved in 82.5% of all eyes with TCC incisions and in 75.3% of all eyes with SST incisions (P < 0.05). When 151 patients with previous ophthalmic conditions were excluded, the difference in BCVA between the two groups was not statistically significant. CONCLUSIONS: Most institutions train residents with the SST technique prior to advancing to TCC. This study demonstrates that with proper teaching, residents can achieve excellent outcomes using TCC incisions, and can therefore be trained in this technique concurrently with SST incisions.

Relative strength of photodynamic biologic tissue glue in penetrating keratoplasty in cadaver eyes.

PURPOSE: To compare the relative strength of photodynamic biologic tissue glue (PBTG) with that of 10-0 nylon sutures in closing penetrating keratoplasty (PKP) wounds in cadaver eyes. SETTING: Corneal Research Laboratory, University of Chicago, Chicago, Illinois, USA. METHODS: A 7 mm central corneal trephination was performed on 8 recently enucleated human eyes. Each corneal button was removed and then resutured in its original position, using 4 interrupted 10-0 nylon cardinal sutures and PBTG (n = 7) or 16 interrupted 10-0 nylon sutures (n = 1). Wound leak and incisional bursting pressures were determined. RESULTS: The average pressure at which wound leak and iris prolapse occurred was 124 mm Hg (range 70 to 180) and 185 mm Hg (range 90 to 300), respectively. The pressure required to create wound leak increased as the time between glue application and pressurization of the globe lengthened (mean 22 minutes, range 5 to 60 minutes), indicating that the bonding and stability of the adhesive increased with time. In contrast, the control eye developed wound leak at 70 mm Hg and iris prolapse at 300 mm Hg. CONCLUSIONS: Photodynamic biologic tissue glue was comparable to sutures in providing adequate corneal wound strength in PKP in a cadaver eye model. Wound closure with PBTG may reduce the number of sutures required in corneal transplantation and decrease the incidence of suture-related complications and allograft rejection.

Minoxidil-induced alteration of corneal topography after radial keratotomy.

PURPOSE: To determine the antiproliferative effect of minoxidil on human corneal epithelium (hCE) proliferation in vitro and to assess whether topical minoxidil can significantly alter corneal topography after radial keratotomy (RK) by inhibiting myofibroblast activity in the keratotomy wound. SETTING: Corneal Research Laboratory, University of Chicago, Illinois, USA. METHODS: In the in vitro evaluation, proliferating hCE was exposed to minoxidil (0.1 to 2.0 mM) for 96 hours to determine the minimum inhibitory dose. Human corneal epithelium cell proliferation was assessed by the incorporation of bromodeoxyuridine (BRDU) into DNA. In the in vivo analysis, eight New Zealand albino rabbits had an eight-incision bidirectional RK on one eye and were divided into two groups. The control eyes (n = 3) received tobramycin and dexamethasone (TobraDex), ciprofloxacin hydrochloride (Ciloxan), and balanced salt solution (BSS) drops four times a day for 3 weeks, while the treatment eyes (n = 5) received TobraDex, Ciloxan, and minoxidil 1.0 mM drops four times daily for 3 weeks. The net change in corneal curvature at 3 weeks was analyzed with corneal topography. Myofibroblast activity in the keratotomy wound was assessed using alpha smooth muscle actin staining techniques. RESULTS: At concentrations of 1.0 mM and above, minoxidil caused a statistically significant, dose-dependent reduction in hCE cellular proliferation ranging from 29 to 44% (P < .05). Minoxidil (1.0 mM) caused a statistically significant central corneal flattening effect of 4.66 diopters (D) after RK in the treatment eyes compared with 1.11 D in the control eyes (P = .05). Histologically, minoxidil-treated keratotomy wounds lacked cells with contractile elements consistent with myofibroblast differentiation. Corneal epithelial wound healing was similar in both groups. CONCLUSION: At the appropriate dose, topical minoxidil may be a useful adjunctive treatment that can reduce the number of undercorrections after mini-RK without apparent toxicity to the corneal epithelium.

Photodynamic biologic tissue glue to enhance corneal wound healing after radial keratotomy.

PURPOSE: To evaluate the effect of photodynamic biologic tissue glue (PBTG) on corneal wound healing after radial keratotomy (RK). SETTING: Cornea Research Laboratory, The University of Chicago, Chicago, Illinois, USA. METHODS: Bidirectional, eight-incision RK was done in one eye of eight Dutch pigmented rabbits. Then, PBTG was inserted into the RK incisions and activated with an argon blue-green laser in four treatment eyes. The rabbits were divided into three groups: early, in which corneal wound healing was assessed at 1 and 3 weeks; late, in which corneal wound healing was assessed at 8 weeks; enhancement. RESULTS: The PBTG-treated keratotomy wounds had a more prominent epithelial healing response immediately after RK and a decreased propensity for wound dehiscence. Collagen fiber arrangement in the PBTG-treated incisions was sagittal to the keratotomy wound 1 to 3 weeks after RK and then changed to a transverse orientation across the keratotomy wound by 8 weeks. The control keratotomy wounds had a less prominent epithelial healing response and developed late disorganization of the posterior keratotomy wound at 8 weeks. Keratometry measurements 2 months after RK showed corneal flattening of 1.0 diopter (D) in the PBTG-treated eye and 6.5 D in the control eye, which is consistent with histologic studies showing more advanced wound healing in the PBTG-treated eyes. After RK enhancement, the PBTG-treated eye resisted further corneal flattening and had 4.5 D of corneal steepening; the control eye had 2.0 D of additional corneal flattening. CONCLUSION: The nontoxic, laser-activated adhesive PBTG accelerated corneal wound healing after RK and simulated the placement of sutures into the RK wound. Thus, PBTG may be an alternative to sutures to correct hyperopia after RK in humans.

Inhibition of proliferating lens epithelium with antitransferrin receptor immunotoxin.

We investigated the effect of an antitransferrin receptor immunotoxin (454A12-rRA) on proliferating human and baboon lens epithelium in vitro. Human and baboon lens epithelial cells grown in modified TC-199 medium at 35 degrees Celsius in 7% CO2 were seeded in 24 well plates at a density of 17,500 cells/ml to 40,000 cells/ml. The cells were exposed to various concentrations of 454A12-rRA for seven days. The sensitivity of proliferating human lens epithelium to 454A12-rRA was dependent on the dose, with a 60% to 70% reduction in cell counts at immunotoxin concentrations of 100 ng/ml and above. The immunotoxin had no significant effect on baboon lens epithelium in vitro, which suggests that it is specific for human tissue. By preventing the proliferation of human lens epithelial cells, immunotoxin 454A12-rRA may be useful in the management of posterior capsule opacification after planned extracapsular cataract surgery.

Treatment of contact lens-related ocular surface disorders with autologous conjunctival transplantation.

The authors describe two cases of chronic ocular surface disorder caused by the use of soft contact lenses. These cases demonstrated persistent corneal epithelial abnormalities, indolent ulceration, superficial stromal scarring, peripheral vascularization, and decreased visual acuity (worse than 20/400). Both cases were refractory to medical management, including discontinuation of contact lenses and topical medications. Autologous conjunctival transplantation restored the ocular surface with the return of good visual acuity (better than 20/40). Tissue culture demonstrated a decreased replication rate in the limbal epithelial cells, which suggests that epithelial stem cell dysfunction may be responsible for this ocular surface disease.