PubMed Health⌕ Search

Biomedical subjects

R A Quintero

Publications and source records attributed to R A Quintero.

At least 19 recordsLinked to original sources
PubMed2005

Management of twin-twin transfusion syndrome in pregnancies with iatrogenic detachment of membranes following therapeutic amniocentesis and the role of interim amniopatch.

OBJECTIVE: Detachment of membranes may occur after therapeutic amniocentesis for twin-twin transfusion syndrome (TTTS). Subsequent amniocenteses or endoscopic fetal therapy may be hindered or made altogether impossible by this complication. The purpose of this study was to describe our experience in the assessment and management of TTTS patients with iatrogenic detached membranes (IDM). METHODS: Patients with IDM referred for fetal surgery for TTTS were considered ineligible for standard surgery and were offered different alternatives, including expectant management, serial amniocentesis, or an attempt at surgery with or without prior amniopatch. Pregnancy outcomes were compared between surgical and non-surgical patients. RESULTS: Nine hundred and forty-four patients with a diagnosis of TTTS were referred between July 1997 and December 2004, of whom 322 (34.1%) had a prior therapeutic amniocentesis. Twenty-six of the 322 patients (8%) had IDM. Ten patients opted to be managed with subsequent amniocenteses, two of which had an amniopatch. One patient had voluntary interruption of pregnancy. Fifteen patients underwent surgery, 10 of whom underwent an amniopatch. Overall, resealing of membranes occurred in 8/12 (66%) patients treated with an amniopatch. Survival of at least one fetus was greater in patients treated surgically with or without an amniopatch (12/15, 80% vs. 4/11, 36%, P = 0.04). CONCLUSION: Membrane detachment is an important complication of therapeutic amniocentesis in the treatment of TTTS. Although successful treatment of IDM can be achieved with an interim amniopatch, this alternative is not without risks. Therapeutic amniocenteses should be discouraged in patients considering endoscopic fetal surgery for TTTS.

Amniocentesis↗
PubMed2004

Umbilical cord occlusion of the donor versus recipient fetus in twin-twin transfusion syndrome.

OBJECTIVES: To compare the technical characteristics and perinatal outcomes of selected twin-twin transfusion syndrome (TTTS) cases treated with primary umbilical cord occlusion (UCO) of the donor vs. recipient twin. METHODS: TTTS patients who underwent primary UCO via ultrasound endoscopic-guided umbilical cord ligation (UCL) or endoscopic umbilical cord photocoagulation (UCP) were eligible for the study. Primary UCO was offered only if a discordant lethal anomaly was present or by patient choice in TTTS Stages III/IV on the cord of the fetus with abnormal Doppler studies or hydrops. RESULTS: Primary UCO was performed in 25 TTTS cases between July 1997 and June 2002. UCO was performed in six (24%) donor twins and 19 (76%) recipient twins. UCL was performed in 23 cases and UCP in two cases. Overall, 22 (88%) patients had liveborn infants. There were no differences in cotwin survival (100% vs. 84.2%), median gestational age at delivery (34.8 vs. 33.8 weeks) and preterm premature rupture of membranes rate (16.6% vs. 15.7%) whether the donor or recipient twin, respectively, was the subject of UCO. However, two-trocar access (50% vs. 5.3%; P = 0.03) and amnioinfusion (83.3% vs. 0%; P < 0.001) were required more often in the UCO of the donor than of the recipient twin, respectively. Operating time (75 vs. 40 min) was significantly longer in UCO of the donor twin (P = 0.04). UCP was more likely to be used in occlusion of the donor's cord (33%) than of the recipient's cord (0%; P = 0.05). CONCLUSION: Primary UCO of the donor twin is technically more demanding than that of the recipient twin, but perinatal outcomes of the cotwins are comparable.

Chi-Square Distribution↗
PubMed2004

Ultrasound assessment of venous blood flow before and after laser therapy: approach to understanding the pathophysiology of twin-twin transfusion syndrome.

OBJECTIVE: To estimate direction and volume of blood exchange between the donor twin and recipient twin by ultrasound assessment of blood flow in the umbilical vein before and after selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS). METHODS: Forty-one TTTS patients underwent Doppler examination of the umbilical vein before and 24 h after SLPCV. The diameter and mean time-averaged velocity of the umbilical vein were estimated. Total umbilical venous flow (TUVF) was calculated as follows: TUVF (mL/min) = mean time-averaged velocity (cm/s) x mean cross-sectional area (cm2) x 60 (s). RESULTS: TUVF was significantly higher in the recipient (111.2 mL/min) than in the donor twin (44.8 mL/min) before SLPCV (P < 0.0001). However, TUVF was no different between the recipient and the donor twin after SLPCV (93.1 vs. 70.7 mL/min, recipient and donor twin, respectively, P = 0.11). The donor twin's TUVF increased after surgery (P < 0.0001), while the recipient twin's TUVF decreased (P = 0.041). The median postoperative increase in the donor twin's TUVF of 25.9 mL/min had a corresponding decrease of TUVF in the recipient twin of 18.1 mL/min (P = 0.27). CONCLUSIONS: Our data suggest that untreated TTTS is characterized by excessive umbilical venous blood flow in the recipient twin relative to the donor twin. Laser surgery results in concordant changes in umbilical venous flow in opposite directions between the donor and recipient twins, eliminating the initial imbalance. Our results lend support to the fundamental hypothesis of unbalanced blood flow exchange (net flow from donor to recipient) between monochorionic twins as the cause for TTTS and that laser surgery eliminates the pathophysiological cause.

Blood Flow Velocity↗
PubMed2004

The cocoon sign: a potential sonographic pitfall in the diagnosis of twin - twin transfusion syndrome.

OBJECTIVES: To investigate the frequency and clinical importance of the cocoon sign in twin-twin transfusion syndrome (TTTS). METHODS: Charts and ultrasound images of all pregnancies with TTTS that underwent selective laser photocoagulation of communicating vessels at our institution over a 1-year period were retrospectively reviewed for a cocoon sign. TTTS had been diagnosed and prospectively staged if monochorionicity was suspected and the maximum vertical pocket (MVP) of amniotic fluid in one gestational sac was >/=8 cm, while the MVP in the other gestational sac was </=2 cm. The cocoon sign was diagnosed when there was an ultrasound finding of a donor twin with severe oligohydramnios enveloped by dividing membranes and connected to the uterine wall by a laminar stalk of these membranes. RESULTS: The cocoon sign was noted in 9/58 (15.5%) cases. There were no differences in gestational age and stage of TTTS upon presentation, gestational age at delivery or number of neonatal survivors between the groups of TTTS cases with and those without a cocoon sign. One patient in the cocoon group had been misdiagnosed because the donor twin's MVP was measured from the donor's tethered membranes to the posterior wall of the uterus within the recipient's sac. CONCLUSIONS: The cocoon sign is present in at least 15% of patients with TTTS. Its recognition is important to avoid misdiagnosis of TTTS. The practical implications and potential complications of this sonographic sign are discussed.

Diagnostic Errors↗
PubMed2003

The role of Doppler studies in predicting individual intrauterine fetal demise after laser therapy for twin-twin transfusion syndrome.

OBJECTIVE: To investigate the role of Doppler studies in predicting individual fetal demise in patients scheduled for selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS). METHODS: Doppler studies of the umbilical artery, umbilical vein, ductus venosus, tricuspid valve regurgitation and middle cerebral artery were performed in the donor and recipient twins before and 24 hours after SLPCV. Results were analyzed cross-sectionally and longitudinally. As multiple comparisons were made, an a priori alpha rejection was set at P < 0.001. RESULTS: One hundred and ten consecutive patients were available for analysis. Overall fetal survival was 68.6% (151/220) with at least one survivor in 88.2% (97/110) of cases. Absent or reversed end-diastolic velocity in the umbilical artery of the donor twin was the only preoperative Doppler result predictive of intrauterine fetal demise (IUFD) (10/15, 66.7%, P < 0.001). Postoperatively, reversed flow during atrial contraction in the ductus venosus of the donor twin showed a trend towards prediction of IUFD of this fetus (4/5, 80%, P = 0.007). No other Doppler studies, including the longitudinal analyses, were predictive of IUFD. CONCLUSIONS: Our data suggest that preoperative absent or reversed end-diastolic velocity in the umbilical artery may be useful in predicting individual fetal demise of the donor twin in TTTS patients scheduled for SLPCV. This may reflect the role of decreased individual placental mass that may be associated with some donor twins. The inability of other Doppler studies to predict individual IUFD may be explained preoperatively by the effect of the interfetal vascular connections on the individual Doppler signals and postoperatively by the effect of surgery or the timing of the assessment. Our findings may be important in patient counseling, in furthering understanding of the disease, and perhaps in improving surgical technique.

Cross-Sectional Studies↗
PubMed2003

In vivo endoscopic assessment of arterioarterial anastomoses: insight into their hemodynamic function.

OBJECTIVE: To assess endoscopically the hemodynamic function of arterioarterial (AA) anastomoses in twin-twin transfusion syndrome (TTTS) and monochorionic selective intrauterine growth restriction (IUGR). MATERIALS AND METHODS: The videotapes of TTTS and IUGR patients undergoing laser surgery between July 1997 and December 2001 were reviewed for the presence of AA anastomoses. The hemodynamic equator was defined as the site within the AA anastomosis with color flashing. AA anastomoses were classified as having unidirectional flow, having bi-directional flow, or being non-functional, depending on whether the hemodynamic equator reached a returning vein to one, both, or neither twin, respectively. TTTS was classified in stages as previously described. RESULTS: AA anastomoses were present in 35/183 (19.1%) of TTTS and in 12/24 (50%) IUGR patients. Of these, the hemodynamic equator was visible in 8/35 (22.8%) TTTS patients (all in stage III, and mostly in atypical stage III) and in 6/12 (50%) IUGR patients (overall 14/47, 29.8%). Of the 14 patients with a visible hemodynamic equator, 13 (92.8%) AA anastomoses showed unidirectional (9/13, 69.2% from the smaller to the larger twin) flow, and only 1/14 (7.1%) showed bi-directional flow. CONCLUSION: The hemodynamic equator is visible in approximately 30% of patients with AA anastomoses. Within this group, most AA anastomoses behave as functional arteriovenous anastomoses, and the direction of flow can be from the smaller to the larger twin or vice versa. The data suggest a correlation between sonographic findings and placental vascular design, also implying possible interfetal oxygenation differences. Further assessment of the functional behavior of AA anastomoses is warranted to understand the pathophysiology of TTTS and selective IUGR.

Adult↗
PubMed2003

Umbilical cord transection in twin-reverse arterial perfusion syndrome with the use of a coaxial bipolar electrode (Versapoint).

Umbilical-cord occlusion has been proposed for the treatment of twin-reverse arterial perfusion syndrome (TRAP). Transection of the umbilical cord is necessary in patients with monoamniotic or 'pseudomonoamniotic' TRAP to avoid subsequent cord entanglement and demise of the pump twin. We present a case of TRAP in which the umbilical cord was successfully ligated with suture and transected with the Versapoint electrode.

Adult↗
PubMed2003

Twin-twin transfusion syndrome in a dizygotic monochorionic-diamniotic twin pregnancy.

We present a case of twin-twin transfusion syndrome with discordant gender. Monochorionicity was confirmed by surgical pathology. Cytogenetic analysis showed normal 46,XX and 46,XY karyotypes. Microsatellite analysis using reliable pericentromeric markers was consistent with dispermic fertilization of two separate ova. This suggests that monochorionicity, rather than zygosity, may be responsible for the development of placental vascular anastomoses.

Abortion, Spontaneous↗
PubMed2002

Operative fetoscopy via telesurgery.

We describe a case in which telesurgical consultation from Tampa, Florida, USA was used to accomplish operative fetoscopy in Santiago, Chile for the treatment of a twin pregnancy involving an acardiac twin. The procedure was successful and a healthy infant was delivered at 37.5 weeks. Operative fetoscopy, a surgical approach to correct birth defects in utero via combined ultrasound and endoscopy, is only available in a handful of centers worldwide. Telesurgery makes use of telecommunication to allow a surgeon at a primary operating site to consult with another experienced surgeon for complex surgical cases. This case illustrates the potential for ultrasound and telesurgery to expand the horizons of operative fetoscopy.

Adult↗
PubMed2001

In-utero treatment of fetal bladder-outlet obstruction by a ureterocele.

Fetal bladder-outlet obstruction by ureteroceles is usually treated at birth. However, such obstruction may be detrimental to the health of the fetus and so in-utero correction is preferable. We describe the successful cytoscopy guided laser incision, with no complications, of a uterocele that was causing bladder-outlet obstruction in a fetus of 19 weeks and 6 days gestation.

Adult↗
PubMed2001

Selective laser photocoagulation of communicating vessels in severe twin-twin transfusion syndrome in women with an anterior placenta.

BACKGROUND: We describe two techniques for the laser treatment of twin-twin transfusion syndrome in women with anterior placentas. TECHNIQUE: In the first technique, anastomoses were photocoagulated using a flexible endoscope through a single port. The second technique used a side-firing laser fiber with a rigid angled-view endoscope (two ports). EXPERIENCE: Seventy-two women had surgery between July 1997 and December 1999, 35 (48.6%) of whom had anterior placentas. Survival was similar for fetuses with anterior (80%) and posterior (75.6%) placentas, but operating time was significantly longer for those with anterior placentas (81.1 compared with 64.4 minutes for the anterior and posterior placentas, respectively; P = .02, Student t test). At least one fetus survived in 76% (16 of 21) of women treated with flexible endoscopes and 86% (12 of 14) of those treated with the side-firing lasers. Six of 72 women (8.3%) had patent vascular anastomoses on placental examination, and five of them had anterior placentas (P = .08, Fisher exact test). CONCLUSION: Although anterior placentas are surgically more challenging than posterior placentas, both techniques allow an effective percutaneous approach to the laser treatment of twin-twin transfusion syndrome.

Female↗
PubMed2001

New horizons in the treatment of preterm premature rupture of membranes.

In the last 5 years, significant experience has been gained in the clinical understanding and treatment of PPROM. From this work, one can conclude that iatrogenic PPROM is not only a different entity etiologically, but also in its clinical behavior and response to therapeutic measures. The current success rate with the amniopatch allows the author [figure: see text] to suggest that iatrogenic PPROm should no longer be viewed as a devastating complication of pregnancy. Instead, it should be viewed as a readily treatable condition with the aminopatch. Regarding spontaneous PPROM, work suggests that perhaps, in a select group of patients in which infection has not set in and in which a smaller and better defined membrane defect may exist, there is the potential for developing a surgical technique that may successfully graft the defect and allow the integrity of the amniotic membrane to be restored. The actual surgical technique, the materials to be used, and the approach (transabdominal versus transcervical) are all areas of research for the future. Meanwhile, continued efforts are warranted to decipher whether this obstetric complication can one day be conquered.

Adult↗
PubMed2001

Selective photocoagulation of communicating vessels in the treatment of monochorionic twins with selective growth retardation.

OBJECTIVE: Current treatment of patients with selective intrauterine growth retardation in monochorionic twins includes expectant management, termination of pregnancy, or umbilical-cord occlusion. The purpose of this study was to assess the outcome of monochorionic twins with selective intrauterine growth retardation who were treated with selective laser photocoagulation of the communicating vessels. STUDY DESIGN: Monochorionic twin pregnancies with selective intrauterine growth retardation at less than 26 weeks were eligible for the study. Selective intrauterine growth retardation was defined as <10th percentile for gestational age. Absent or reverse end-diastolic velocity in the umbilical artery of the twin with selective intrauterine growth retardation was required for eligibility after January 2000. RESULTS: Thirty patients met the criteria for the study: 17 patients were treated expectantly (group I); 2 patients underwent umbilical-cord ligation of the twin with selective intrauterine growth retardation, and 11 patients underwent selective laser photocoagulation of the communicating vessels (group II). Survival rates for at least 1 fetus were no different between groups I and II (14/17 [82.3%] vs 8/11 [72.3%]; P = .4). However, concomitant demise of the co-twin occurred in 4 of 7 patients, and iatrogenic premature delivery for deterioration of the twin with selective intrauterine growth retardation was necessary in 2 patients in group I, which resulted in significant neonatal morbidity. Of the live-born babies, neurologic handicap was present in 3 of 22 babies (13.6%) versus 0 of 12 in groups I and II, respectively (P < .0001). CONCLUSION: Selective intrauterine growth retardation in monochorionic twins can be effectively treated with selective laser photocoagulation of the communicating vessels. By unlinking the circulations between the fetuses, the pregnancy is rendered "functionally" dichorionic, which improves pregnancy treatment and results in decreased neonatal morbidity. This approach constitutes a new valuable alternative in the treatment of monochorionic twin pregnancies with selective intrauterine growth retardation. A randomized clinical trial of expectant treatment versus selective laser photocoagulation of the communicating vessels for monochorionic selective intrauterine growth retardation can be considered.

Blood Vessels↗