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Biomedical subjects

Rubén A Quintero

Publications and source records attributed to Rubén A Quintero.

11 recordsLinked to original sources
PubMed2006

The role of laser surgery in dissecting the etiology of absent or reverse end-diastolic velocity in the umbilical artery of the donor twin in twin-twin transfusion syndrome.

OBJECTIVE: This study was undertaken to gain insight on the cause of absent or reverse end-diastolic velocity (AREDV) in the umbilical artery (UA) of the donor twin by analysis of individual placental mass and vascular anastomoses in patients with twin-twin transfusion syndrome (TTTS) treated with laser. STUDY DESIGN: TTTS patients who successfully underwent selective laser photocoagulation of communicating vessels (SLPCV), 16 and 26 weeks' gestation, with both twins born alive and complete Doppler and placental data were considered eligible for the study. Doppler examination of the UA was performed before and 24 hours after SLPCV. Abnormal UA Doppler findings were defined as persistent AREDV. Pre- and post-SLPCV UA Doppler results yielded the following 4 groups: (1) normal-normal; (2) normal-abnormal; (3) abnormal-normal; and (4) abnormal-abnormal. The types of vascular anastomoses were categorized during surgery. Individual placental territory (IPT) was defined as individual placental weight divided by total placental weight x 100. RESULTS: There were 132 cases in group 1 and no patients in group 2. AREDV resolved in 78% (28/36) of patients (group 3) and remained unchanged in 22% (8/36) (group 4). The mean IPT-donor in group 4 was significantly smaller than in group 1 (P = .015). Patients with preoperative AREDV (groups 3 and 4) were more likely to have artery-to-artery anastomoses (P = .002). However, AREDV resolved in 57% (16/28) patients without artery-to-artery anastomoses. CONCLUSION: Preoperative AREDV may result from a small IPT, placental vascular anastomoses, or both. AREDV resulting from a small IPT may have a similar cause to that of singletons, and may be inferred by lack of postoperative resolution. Resolution of AREDV after SLPCV implies the presence of an adequate IPT and removal of donor hypotension.

Blood Flow Velocity↗
PubMed2006

Surgical management of twin reversed arterial perfusion sequence.

OBJECTIVE: The purpose of this study was to review our experience in the management of twin reversed arterial perfusion sequence to derive management recommendations. STUDY DESIGN: All patients with twin reversed arterial perfusion sequence who were seen for consultation between 1993 and 2004 were studied. Criteria for umbilical cord occlusion included abdominal circumference of the twin reversed arterial perfusion fetus that was more than or equal to the pump twin, polyhydramnios (maximum vertical pocket > or = 8 cm), abnormal Doppler studies or hydrops of the pump twin, or monoamniotic twins. Various surgical and access techniques for umbilical cord occlusion were used as they were developed. RESULTS: Seventy-four patients with twin reversed arterial perfusion sequence were studied. Sixty-five patients were considered surgical candidates, of which 51 patients underwent umbilical cord occlusion attempt. The overall perinatal survival for surgical candidates who had umbilical cord occlusion was 65% (33/51 patients) versus 42.9% (6/14 patients) for the surgical candidates who did not undergo umbilical cord occlusion (P = .1). However, perinatal outcomes in surgical patients were significantly better than expectantly treated surgical candidates if the dividing membrane was not disrupted purposely (22/28 patients; 78.5%; P = .02). Surgery within the sac of the twin reversed arterial perfusion fetus was feasible in 23.5% of patients and was associated with no incidence of premature rupture of membranes, with 83% perinatal survival, and with a significantly greater gestational age at delivery (36 weeks). There were no significant differences in perinatal outcome relative to the specific surgical technique that was used. CONCLUSION: Surgical management of twin reversed arterial perfusion sequence is indicated in high-risk patients. The surgical approach and the surgical technique should be tailored to the specific clinical presentation, preferably by performing the surgery within the sac of the twin reversed arterial perfusion sequence fetus and avoiding disruption of the dividing membrane.

Arteries↗
PubMed2005

Individual placental territories after selective laser photocoagulation of communicating vessels in twin-twin transfusion syndrome.

OBJECTIVE: Intrauterine fetal death of one or both twins after laser therapy (selective photocoagulation of communicating vessels) may occur, in part, from insufficient individual placental mass. The objective of this study was to assess the percentage of individual placental mass (individual placental territory) that is associated with fetal survival in twin-twin transfusion syndrome after selective photocoagulation of communicating vessels. STUDY DESIGN: Placentas from 72 patients with selective photocoagulation of communicating vessels-treated twin-twin transfusion syndrome without intrauterine fetal death and from 61 monochorionic pregnancies without twin-twin transfusion syndrome (control subjects) were assessed. The placentas were weighed fresh (total placental mass) and cut along the vascular equator, which yielded the individual placental mass and the individual placental territory. Patency of anastomoses was ruled out with air-injection. The individual fetoplacental ratio was obtained by dividing birth weight by the corresponding individual placental mass. RESULTS: The 5th percentile individual placental territory that was associated with fetal survival was 27% in control subjects and 18% in cases with twin-twin transfusion syndrome, with a minimum of 10% to 14%, respectively. There were no differences in total placental mass, individual placental mass, individual placental territory, or individual fetoplacental ratio between pregnancies with twin-twin transfusion syndrome and control subjects. However, corrected for gestational age, the birth weight of recipient and donor twins were significantly smaller than control subjects. The individual placental territory of donors was statistically smaller than that of recipients. Individual placental territories were not different within control subjects. CONCLUSION: Fetal survival typically is associated with at least 18% of individual placental territory after selective photocoagulation of communicating vessels for twin-twin transfusion syndrome, but it can occur with as little as 10% to 14% individual placental territory. Decreased birth weight of the donor twin could result from relative decreased percentage of individual placental territory or from the loss of nutrients to the recipient twin. Decreased birth weight of the recipient twin could result from partial deprivation of functional placental tissue after surgery. Our findings may contribute to the understanding of normal and pathologic monochorionic twin gestations, in the counseling of patients, and potentially to the improvement of surgical treatment of twin-twin transfusion syndrome.

Adult↗
PubMed2005

In utero cardiac fetal surgery: laser atrial septotomy in the treatment of hypoplastic left heart syndrome with intact atrial septum.

OBJECTIVE: The purpose of this study was to report a novel technique, laser atrial septotomy, for the in utero treatment of hypoplastic left heart syndrome with intact atrial septum. STUDY DESIGN: In utero atrial septotomy by Neodymium-YAG laser photofulguration in a fetus with hypoplastic left heart syndrome (HLHS) and intact atrial septum was performed at 30 4/7 weeks of gestation. Percutaneous fetal cardiocentesis was performed to guide a contact (Neodymium-YAG) laser fiber into the right atrium with the objective of creating an interatrial communication by photofulguration of the septal tissue. RESULTS: New onset of blood flow from the left to the right atrium was confirmed by color Doppler imaging during the procedure. The neoatrial septal defect remained patent until delivery. A 3400-g neonate was born by spontaneous vaginal delivery at 37 weeks of gestation. A first stage Norwood procedure was performed on the first day of life and surgical correction of an obstructed right pulmonary vein at 3 months. Although pulmonary vascular resistance was normal at cardiac catheterization at 2 months of age, the infant died at 5 months of age from multiple organ failure. An autopsy was declined. CONCLUSION: In utero laser atrial septotomy is feasible. Further experience is necessary to determine the risks and benefits of this technique for the treatment of fetuses hypoplastic left heart syndrome with intact atrial septum.

Adult↗
PubMed2004

Advances in fetal cardiac intervention.

Fetal cardiac intervention is in a rapid state of progress now. Attempts are being made to prevent fetal hydrops due to congenital heart defects, to recruit hypoplastic ventricles, to create a two-ventricle circulation after birth, and to remodel the fetal pulmonary vascular bed whose outlet is obstructed. Open heart surgery in the fetus has yet to be done successfully, but interventions for improved cardiac outcomes are now being tested. Their outcomes will depend, in large part, on their successful physiological effects. How to measure these and quantitate the effects of our interventions will require further advances in the understanding of these diseases-both their natural and unnatural courses. New ultrasound techniques and assessment tools to assess fetal cardiac wellness could enhance the limited progress in fetal intervention in the heart so far.

Aortic Valve Stenosis↗
PubMed2003

Treatment of previable premature ruptured membranes.

We have gained significant experience in the clinical understanding and treatment of PPROM in the last 5 years. From our work we can conclude that iatrogenic PPROM is not only a different entity etiologically, it is also different than spontaneous PPROM in its clinical behavior and response to therapeutic measures. Our current success rate with the amniopatch allows us to suggest that iatrogenic PPROM should no longer be viewed as a devastating complication of pregnancy. Instead, as other investigators corroborate our successful experience with the amniopatch, this procedure might become standard treatment for this unusual but frustrating complication of prenatal intervention. Regarding spontaneous PPROM, our work suggests that perhaps, in a select group of patients (in whom infection has not set in and in whom a smaller and better defined membrane defect might exist), there is the potential for developing a surgical technique that might graft the defect successfully 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 areas of research for the future. Meanwhile, continued efforts are warranted to decipher whether or not this obstetrical complication can one day be conquered.

Amnion↗
PubMed2003

Twin-twin transfusion syndrome.

The understanding and management of twin-twin transfusion syndrome has evolved significantly over the past few years. Improved and standardized sonographic diagnostic criteria, understanding of the heterogeneic nature of the syndrome, development of an anatomical and reproducible surgical technique for the identification of vascular anastomoses, and technological advances and developments now allow clinicians to view the disease as a more readily understandable and treatable condition. Many tasks remain, including education of peers, better screening and diagnosis, and further development of surgical instruments. Generalization of treatment outcomes should no longer apply given the varied results with disease stage. Confirmation of our tailored approach to management of the disease according to stage should soon be corroborated with an appropriate clinical trial.

Female↗
PubMed2003

Stage-based treatment of twin-twin transfusion syndrome.

OBJECTIVE: The purpose of this study was to compare the outcomes of patients with twin-twin transfusion syndrome who were treated with either serial amniocentesis or selective laser photocoagulation of communicating vessels according to disease severity (stage). STUDY DESIGN: Centers that were experienced in the treatment of twin-twin transfusion syndrome were invited to share stage-based perinatal outcome data. All patients met basic standard sonographic criteria for twin-twin transfusion syndrome (polyhydramnios maximum vertical pocket, > or =8 cm; oligohydramnios maximum vertical pocket, < or =2 cm). Gestational age at first treatment was <27 weeks of gestation. RESULTS: Three centers submitted stage-based data, for a total of 173 patients (serial amniocentesis, 78 patients from all 3 centers) and 95 selective laser photocoagulation of communicating vessels (1 center). The distribution of patients by stage was similar in the two groups. Successful pregnancy outcome (at least 1 surviving infant) was correlated inversely with stage in the serial amniocentesis but not in the selective laser photocoagulation of communicating vessels group and was significantly lower in the serial amniocentesis (66.7%) than in the selective laser photocoagulation of communicating vessels group (83.2%). Neurologic morbidity was related directly to stage in the serial amniocentesis group but not in the selective laser photocoagulation of communicating vessels group and was significantly higher in the serial amniocentesis (24.4%) than in the selective laser photocoagulation of communicating vessels (4.2%) group. Intact neurologic survival (at least 1 surviving infant without neurologic morbidity) was significantly lower in the serial amniocentesis group than in the selective laser photocoagulation of communicating vessel group (51.3% vs 78.9%), particularly in stage III and stage IV (23.5% vs 72.7% in stage IV). Patients who were treated with selective laser photocoagulation of communicating vessels were 2.4 times more likely to have at least one survivor than those treated with serial amniocentesis. CONCLUSION: Our study suggests a relationship between perinatal morbidity and mortality rates and stage in serial amniocentesis but not in selective laser photocoagulation of communicating vessel-treated twin-twin transfusion syndrome patients. These findings could be used to tailor the treatment of twin-twin transfusion syndrome. A clinical trial to confirm these results is being organized by our research groups.

Amniocentesis↗
PubMed2002

Placental types and twin-twin transfusion syndrome.

OBJECTIVE: The purpose of this study was to assess the value of a proposed classification of monochorionic placenta in reference to twin-twin transfusion syndrome. STUDY DESIGN: The placentas from laser-treated patients with twin-twin transfusion syndrome and from uncomplicated monochorionic pregnancies that were delivered between January 1997 and December 2000 were included in the study. Placentas were classified as type A (no anastomoses), type B (only deep anastomoses), type C (only superficial anastomoses), and type D (deep and superficial anastomoses). The number and type of anastomoses were documented in each placental type. The severity of twin-twin transfusion syndrome was assessed in stages, as previously described. The relationship between placental types and the development and severity of twin-twin transfusion syndrome was determined. RESULTS: One hundred thirty-one placentas were examined. Twin-twin transfusion syndrome developed in 0% (0/4 placentas) of type A, in 100% (85/85 placentas) of type B, in 5.6% (1/18 placentas) of type C, and in 79.17% (19/24 placentas) of type D placentas. An average of 4.17 (range, 1-11) vascular anastomoses was found. The mean number of superficial anastomoses was not different between patients with twin-twin transfusion syndrome and patients with no twin-twin transfusion syndrome (1.6 vs 1.71, respectively; P =.69, Student t test). The presence or absence of superficial anastomoses was not associated with differences in the severity of twin-twin transfusion syndrome. CONCLUSION: This classification represents a practical approach to the surgical pathologic assessment of vascular anastomoses in monochorionic placentas, with a strong clinical correlation. It also allows for the clarification of the relationship between superficial anastomoses and twin-twin transfusion syndrome.

Arteriovenous Anastomosis↗