[The pulmonary artery closure may be a thromboembolic risk factor in patients with bidirectional cavo-pulmonary (Glenn) shunt]. / El cierre arterial pulmonar puede ser un factor de riesgo tromboembólico en pacientes con anastomosis cavopulmonar (Glenn) bidireccional.

Postoperative thrombosis after the Fontan procedure has been well noted in the literature, and its risk factors are also well known. In contrast, thrombosis after the bilateral cavo-pulmonary shunt (Glenn) has been rarely reported and almost always occurs around the anastomosis itself or near it, mainly causing pulmonary embolism. We present 2 cases with cerebral embolism 2-7 months after pulmonary artery closure and Glenn procedure, due to dislodgement of a thrombus in the proximal pulmonary artery stump. Based on these two cases and a few others reported in the literature, we want to call the attention to this new cause of thromboembolism after Glenn and stimulate discussion about its incidence, risk factors and preventive measures.

Usefulness of gastric intramucosal pH for monitoring hemodynamic complications in critically ill children.

OBJECTIVE: To assess the efficacy of gastric intramucosal pH for the evaluation of tissue perfusion and prediction of hemodynamic complications in critically ill children. DESIGN: Open prospective study without controls. SETTING: Pediatric intensive care unit (ICU) of a tertiary care university pediatric hospital. PATIENTS: Thirty critically ill children (16 boys and 14 girls), age range: 3 months-12 years. MEASUREMENTS AND RESULTS: A tonometry catheter was placed in the stomach of all patients on admission to the pediatric ICU. Simultaneous tonometry and arterial gas measurements were made on admittance and every 6-12 h throughout the study; a total of 202 measurements were made. The catheter was removed after extubation and/or when the patient was hemodynamically stable. Intramucosal pH was calculated using the Henderson-Hasselbalch equation based on the pCO2 of the tonometer and arterial bicarbonate. Intramucosal pH values between 7.30 and 7.45 were considered to be normal. The patient's condition was analyzed using the Pediatric Risk Mortality Score (PRISM). The relations between intramucosal pH and the presence of major hemodynamic complications (cardiopulmonary arrest, shock), minor hemodynamic complications (hypotension, hypovolemia or arrhythmia), death, PRISM score and the duration of the stay in the pediatric ICU were analyzed. Intramucosal pH on admission was 7.48 +/- 0.15 on average (range 7.04-7.68). Five patients (16%) had an intramucosal pH lower than 7.30 on admission; these patients did not have a higher incidence of hemodynamic complications. The 16 patients (53%) who had an intramucosal pH of less than 7.30 at some time during the course of their disease had more hemodynamic complications than the patients who did not have pH lower than 7.30 (p < 0.0001). Every case of cardiopulmonary arrest and shock was related to intramucosal pH of less than 7.30. Patients with major complications (cardiopulmonary arrest and shock) had lower intramucosal pHs than those with minor hemodynamic complications (p = 0.03); similarly, they had low intramucosal pH readings more often than those with minor complications (p = 0.0032). Intramucosal pH values less than 7.30 had a sensitivity of 90% and a specificity of 98% as a predictor of hemodynamic complications. There was no relation between intramucosal pH lower than 7.30 and either PRISM or the duration of the stay in the pediatric ICU. Patients with intramucosal pH less than 7.20 had a higher PRISM than the patients who did not have pH lower than 7.20 (p < 0.05). A patient who died during the study due to cardiopulmonary arrest had prior intramucosal pH measurements of 7.23 and 7.10, and three patients died of late complications after the end of the study. Hemodynamic complications were not detected with arterial pH. Gap pH (arterial pH-intramucosal pH) and standard pH measurements yielded the same results as gastric intramucosal pH. CONCLUSION: Intramucosal pH could provide a useful early indication of hemodynamic complications in critically ill children.

External argon laser choroidotomy versus needle drainage technique in primary scleral buckle procedures. A prospective randomized study.

PURPOSE: To compare the rates of intraoperative and postoperative complications of external argon laser choroidotomy and needle drainage techniques during scleral buckle procedures for primary retinal detachment. METHODS: A group of 175 patients undergoing scleral buckling for primary retinal detachment was randomly assigned to undergo either external argon laser choroidotomy or needle drainage. Complications associated with drainage of subretinal fluid were categorized as retinal break, retinal incarceration, or hemorrhage (dot, < or = 1 disc diameter [DD], or > 1 DD), and recorded during surgery and 24 hours after surgery. RESULTS: In the group that underwent laser choroidotomy, 12 (13%) of 92 patients had complications, including 4 dot hemorrhages, 3 hemorrhages 1 DD or smaller, 3 hemorrhages larger than 1 DD, 1 retinal incarceration, and 1 suprachoroidal hemorrhage. In the group that underwent needle drainage, 13 (16%) of 81 patients had complications, including 3 dot hemorrhages, 4 hemorrhages 1 DD or smaller, 5 hemorrhages larger than 1 DD, and 1 suprachoroidal hemorrhage. No significant difference was noted between the two groups in the incidence of complications (P = 0.657). CONCLUSION: External argon laser choroidotomy and needle choroidotomy are comparable, safe, and effective ways to drain subretinal fluid during scleral buckle surgery.

Acute posterior multifocal placoid pigment epitheliopathy. An indocyanine green angiographic study.

Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is an idiopathic posterior segment inflammatory disorder of young adults. The pathophysiology is poorly understood, and debate persists as to whether it represents a primary pigment epithelial disorder or a choroidal vascular disease. Indocyanine green angiography was used to study choroidal blood flow in two patients with typical APMPPE. The authors demonstrate profound delayed choroidal filling in addition to extensive areas of choroidal vessel nonperfusion in the acute stage of this disease. Recovery of choroidal blood flow was evident during clinical resolution. Choroidal blood flow abnormalities are present in APMPPE and suggest that the clinical findings of this disease reflect a primary choroidal vascular disease.

Vitrectomy for premacular fibroplasia. Prognostic factors, long-term follow-up, and time course of visual improvement.

Two hundred seventy eyes with premacular fibroplasia consecutively treated by pars plana vitrectomy and membrane peeling were reviewed. This study is among the largest series with long-term follow-up reported to date. Visual improvement of two or more lines was achieved in 43% of eyes at 6 to 12 months, in 54% at 1 to 2 years, in 60% at 2 to 3 years, and in 58% at 3 to 5 years. Overall, complications occurred in 34 eyes (13%). Cataract progression after vitrectomy was noted in 106 (57%) of phakic eyes at 3 to 5 years, and 43 of these eyes underwent subsequent cataract extraction. Mean time to best visual acuity after vitrectomy was slightly less than 1 year for all eyes unless they had cataract worsening with subsequent cataract extraction (1.9 years). Significant factors affecting visual outcome were: preoperative lens status, visual acuity before vitrectomy, duration of preoperative symptoms of distortion and/or blurred vision, and the occurrence of intraoperative complications.

External argon laser drainage of subretinal fluid using the endolaser probe.

The results of 200 consecutive scleral buckling procedures in which the argon endolaser probe was used to create a choroidotomy for drainage of subretinal fluid are reported. This technique was used in any case requiring drainage and was specifically employed in cases in which needle drainage was contraindicated because the detachment was shallow. The argon laser was set at 0.2 seconds, 1.25 watts, and was used with the endolaser probe held adjacent to, but not touching, the choroid. Drainage was successfully accomplished in 98% of cases. Rates of subretinal hemorrhage, retinal incarceration, and perforation related to laser drainage were 5.5%, 2.5%, and 1%, respectively. No large or submacular subretinal hemorrhages occurred. This technique appears to be particularly promising for drainage of shallow retinal detachments.

Transconjunctival anterior retinal cryotherapy for proliferative diabetic retinopathy.

Transconjunctival anterior retinal cryotherapy (ARC) for proliferative diabetic retinopathy (PDR) in 408 eyes was reviewed retrospectively. Of 266 eyes available for analysis for treatment effect on neovascularization, 138 (52%) had reduced neovascularization at 6 months. Eighty (30%) had no change in neovascularization, and 48 (18%) had increased neovascularization at 6 months. Factors having a significant effect on reduction of neovascularization were duration of diabetes and severity of retinopathy. Of 238 eyes available for analysis for treatment effect on vitreous hemorrhage at 6 months, 118 (50%) had reduced vitreous hemorrhage, 80 (33%) had no change, and 40 (17%) had increased vitreous hemorrhage. Severity of vitreous hemorrhage significantly affected the outcome in the subgroup of eyes with both neovascularization and vitreous hemorrhage. Of the total 408 eyes in this series, at 6 months, 172 (44%) had improved visual acuity, 89 (23%) had no change, and 126 (33%) had decreased visual acuity. Retinal detachments developed in 17 eyes (4%) post-treatment, 68 eyes (17%) had significant recurrent vitreous hemorrhage, and 61 eyes (15%) eventually underwent vitrectomy.

Supplemental photocoagulation on the buckle for prevention of surgical revision after scleral buckling procedures.

Supplemental photocoagulation on the buckle appears to be a useful therapeutic modality in selected cases of persistent retinal detachment. In a retrospective review, 71 (63%) of 113 eyes were successfully treated with photocoagulation, thus avoiding the need for surgical revision. Median response time between treatment and postoperative subretinal fluid absorption in the successfully treated eyes was two days, with the majority responding within one day. The one favorable prognostic factor was the use of a soft silicone segmental sponge. Unfavorable prognostic factors included the following: contour of subretinal fluid (combined, ie, both anterior and posterior to the buckle); excessive amount of subretinal fluid; inadequate support of break(s); multiple drainages at first operation; rolled edge in association with a giant break; and residual vitreous traction on the break. Postoperative photocoagulation alone on the buckle did not appear to influence the rate of development of premacular fibroplasia or proliferative vitreoretinopathy.

Neovascular glaucoma: a retrospective analysis of treatment with peripheral panretinal cryotherapy.

A retrospective analysis of thirty-one eyes in thirty patients with neovascular glaucoma (NVG) associated with proliferative diabetic retinopathy or venous occlusive disease was performed. Eyes treated with transconjunctival peripheral panretinal cryotherapy alone, or in combination with limited cyclocryotherapy had improvement or stabilization of visual acuity in 55%, reduction of intraocular pressure in 55%, and stabilization or regression of iris neovascularization in 70% of eyes at 12-14 months post-treatment. Transconjunctival peripheral panretinal cryotherapy alone, or in combination with limited cyclocryotherapy is recommended in the treatment of eyes with NVG and media opacities precluding photocoagulation therapy, or in eyes unresponsive to previous photocoagulation therapy.

Pseudophakic retinal detachments in the presence of various IOL types.

A series of 600 pseudophakic retinal detachments in 578 patients undergoing surgical repair between 1974 and 1984 was reviewed. Patients with previous retinal surgery of less than six months follow-up were excluded. The series included 395 iris-fixated (IF) lenses, 130 anterior chamber (AC) lenses, and 75 posterior chamber (PC) lenses. The overall success rate for retinal detachment was 88% but was significantly better in the PC lens group and significantly worse in the AC lens group. Forty-one percent of all cases achieved 20/40 visual acuity or better, although the AC lens group did worse (28%), while the PC lens group did significantly better (48%). Risk factors that were predictive of failure also were identified. Many of these factors occurred more frequently in the AC lens group and probably are related to the overall worse outcome in eyes with AC lens implants. The implications of these results for retinal and cataract surgeons are discussed.

The Lincoff temporary balloon buckle.

The Lincoff temporary balloon buckle is an equally effective alternative to more conventional techniques in the management of selected retinal detachments. We used this technique in the management of 45 selected primary retinal detachments operated on since Nov. 22, 1980. Initial complete retinal flattening was achieved in 42 eyes (93%). Two of the three eyes that initially did not show complete flattening ultimately went on to do well without further surgery. Redetachment occurred in three of the five aphakic eyes (60%) and in four of the 36 phakic eyes (11%). None of the retinas in the four eyes with intraocular lenses redetached. Conventional scleral buckling techniques were used in the one case of initial failure and in the seven cases of redetachment for a final success rate of 98% after an average follow-up of 13 months.

Limited retinal detachment. A retrospective analysis of treatment with transconjunctival retinocryopexy.

Two hundred forty-one eyes with a "limited retinal detachment" were treated between 1967 and 1983 by transconjunctival retinocryopexy without scleral buckling. Follow-up ranged from 6 months to 10 years (mean, of 34 months). Anatomic reattachment was accomplished with retinocryopexy alone in 95% (228 eyes) of cases. Thirteen eyes (5%) were anatomic failures, but 12 of these were subsequently reattached with additional surgery. Risk factors for anatomic failure included multiple breaks, vitreous hemorrhage, and breaks with a rolled posterior edge. Visual results indicated that 229 eyes (95%) had stable or improved vision, while 12 eyes (5%) lost two or more Snellen lines. Causes for visual deterioration included premacular fibroplasia, proliferative vitreoretinopathy, and preexisting ocular pathology. Single breaks occurred in 172 eyes (71.4%), and multiple breaks in 69 eyes (28.6%). Associated clinical findings included high myopia (17%), surgical aphakia (12%), and retinal detachment in the fellow eye (27%).

Xenon arc photocoagulation of proliferative diabetic retinopathy. A review of 2688 consecutive eyes in the format of the Diabetic Retinopathy Study.

In a retrospective study, 2688 eyes treated with xenon arc photocoagulation which would have qualified for inclusion in the Diabetic Retinopathy Study (DRS) were reviewed in the format of the DRS. When comparable risk groups were compared, the results of treatment were even more favorable than reported in the DRS without the severe complications attributed to xenon treatment in the DRS. A critical analysis of the DRS gives clues for the greater amount of visual loss found with xenon than argon in the DRS. Since these complications may be avoidable in some cases, and since xenon has been shown to be at least as effective as argon, it should continue to be used in the treatment of proliferative diabetic retinopathy.

Preoperative antibiotic soaking of silicone sponges. Does it make a difference?

A prospective randomized trial was carried out during the years 1974 to 1981 to determine whether preoperative antibiotic soaking of silicone sponges used in retinal detachment surgery would reduce the incidence of postoperative infection and extrusion. During this period 2972 consecutive primary scleral buckles were performed and in 921 (31%) of the cases an episcleral sponge was utilized either alone or in conjunction with a hard silicone encircling band. In alternate cases the sponge was soaked in an antibiotic solution for at least 30 minutes prior to insertion. In the remaining cases the sponge was not soaked. Overall, a statistically significant (P = 0.00018) seven-fold reduction in the rate of infection or extrusion was observed in cases where the silicone sponge was soaked preoperatively in antibiotics. An additional result of the study showed the rate of sponge removal was significantly increased by the use of multiple episcleral sponges (P = 0.00002).

Xenon arc photocoagulation of proliferative diabetic retinopathy (a review of 2688 consecutive eyes in the format of the diabetic retinopathy study--DRS).

Over 2500 xenon arc-treated eyes which would have qualified for inclusion in the DRS were reviewed in the format of the DRS. When comparable risk groups were compared, the results of treatment were even more favorable than reported in the DRS without the severe complications attributed to xenon treatment in the DRS. A critical analysis of the DRS gives clues for the greater amount of visual loss found with xenon than argon in the DRS. Since these complications may be avoidable in some cases and since xenon has been shown to be at least as effective as argon, it should continue to be used in the treatment of PDR.

Bupivacaine anesthesia in retinal detachment surgery.

Retinal detachment surgery and other long-duration ocular procedures can be performed safely with local anesthesia, but a long-acting anesthetic is required. A randomized and masked prospective series of 126 scleral buckling procedures was undertaken to test a mixture of bupivacaine (Marcaine), lidocaine (Xylocaine), and epinephrine against lidocaine and epinephrine. The data collected show a conclusive superiority of the bupivacaine mixture in longevity of action and overall performance. Also, there was significantly less variability in the quality of anesthesia with the mixture than with lidocaine (p = .0015).

Pseudophakic retinal detachment.

Our experiences with a small group of patients who had intraocular lens implants performed at the time of cataract extraction, and who subsequently developed retinal detachment are reviewed. The technical problems related to retinal detachment surgery in the presence of intraocular lenses and the results of this surgery are summarized.

Drainage of subretinal fluid: why, when, where and how.

The release of subretinal fluid is only required in certain complicated types of retinal detachment and should be avoided when possible. An important consideration in releasing subretinal fluid is the timing of this step in relation to the application of diathermy or cryotherapy as the primary treatment modality. Drainage should precede application of cryotherapy but follow the use of diathermy. The most satisfactory site for drainage is either immediately above or below the medial or lateral long ciliary nerve, just posterior to the equator of the globe. A technique for drainage of subretinal fluid has been developed and evaluated. An 'L'-shaped scleral flap is dissected to produce a relatively staphylomatous zone and the choroid is perforated near its center.