Mary H. Allen

Staging of twin-twin transfusion syndrome

OBJECTIVE:The purpose of this study was to evaluate the prognostic value of sonographic and clinical parameters to develop a staging classification of twin-twin transfusion syndrome (TTTS).STUDY DESIGN:Severe TTTS was defined as the presence of polyhydramnios (maximum vertical pocket of ≥8 cm) and oligohydramnios (maximum vertical pocket of ≤2 cm). Nonvisualization of the bladder in the donor twin (−BDT) and absence of presence of hydrops was also noted. The middle cerebral artery, umbilical artery, ductus venosus, and umbilical vein in both fetuses were assessed with pulsed Doppler. Critically abnormal Doppler studies (CADs) were defined as absent/reverse end-diastolic velocity in the umbilical artery, reverse flow in the ductus venosus, or pulsatile flow in the umbilical vein. TTTS was staged as follows: stage I, BDT still visible; stage II, BDT no longer visible, no CADs; stage III, CADs; stage IV, hydrops; stage V, demise of one or both twins. Laser photocoagulation of communicating vessels (LPCV) or umbilical cord ligation was performed depending on the severity of the condition. The study was approved by the Institutional Review Board of St. Joseph’s Hospital in Tampa and by the Fetal Therapy Board at Hutzel Hospital, Detroit, and all patients gave informed consent.RESULTS:A total of 80 of 108 referred patients met criteria for surgery, but only 65 were treated surgically: 48 with LPCV and 17 with umbilical cord ligation. Complete Doppler data were obtainable in 41 of 48 LPCV patients. Survival rates by stage for one or two fetuses were statistically different (χ-squared analysis = 12.9, df = 6, p = 0.044). Neither percent size discordance nor gestational age at diagnosis were predictive of outcome.CONCLUSION: Staging of TTTS using the proposed criteria has prognostic significance. This staging system may allow comparison of outcome data of TTTS with different treatment modalities.

Treatment of iatrogenic previable premature rupture of membranes with intra-amniotic injection of platelets and cryoprecipitate (amniopatch): Preliminary experience

OBJECTIVE Our aim was to describe the treatment of iatrogenic previable premature rupture of membranes with the intra-amniotic injection of platelets and cryoprecipitate (amniopatch). STUDY DESIGN Patients with iatrogenic previable premature rupture of membranes and without evidence of intra-amniotic infection underwent transabdominal intra-amniotic injection of platelets and cryoprecipitate through a 22-gauge needle. The study was approved by the Institutional Review Board of St Josephs Hospital in Tampa, Florida, and all patients gave written informed consent. RESULTS Seven patients with iatrogenic preterm premature rupture of membranes underwent placement of an amniopatch. Membrane sealing was verifiable in 6 of 7 patients. Three patients had iatrogenic preterm premature rupture of membranes after operative fetoscopy, 3 cases were after genetic amniocentesis, and 1 was after diagnostic fetoscopy. Three pregnancies progressed well, with restoration of the amniotic fluid volume and no further leakage. Two patients had unexplained fetal death despite successful sealing. One case of bladder outlet obstruction had no further leakage, but oligohydramnios persisted and did not allow unequivocal documentation of sealing. One patient miscarried from twin-twin transfusion, but the amniotic cavity was sealed. CONCLUSIONS Iatrogenic preterm premature rupture of membranes can be treated effectively with an amniopatch. The technique is simple and does not require knowledge of the exact location of the defect. Unexpected fetal death from the procedure may be attributable to vasoactive effects of platelets or indigo carmine. Although the appropriate dose of platelets and cryoprecipitate needs to be established, the amniopatch may mean that iatrogenic preterm premature rupture of membranes no longer needs to be considered a devastating complication of pregnancy.

Sequential selective laser photocoagulation of communicating vessels in twin–twin transfusion syndrome

Objective. We have previously described the selective laser photocoagulation of communicating vessels (SLPCV) technique for the treatment of twin–twin transfusion syndrome (TTTS). Because TTTS is thought to result from a net transfer of blood from the donor twin to the recipient twin, we hypothesized that lasering the arteriovenous anastomoses from the donor to the recipient (AVDRs) first (sequential SLPCV or SQLPCV) would result in an improved hemodynamic status and decreased likelihood of intrauterine fetal demise of the donor twin (IUFD-D). Materials and methods. The diagnosis of TTTS was made by ultrasound showing the combined presence of a maximum vertical pocket ≥ 8 cm in one sac and ≤2 cm in the other in a monochorionic/diamniotic twin pregnancy. Triplet pregnancies and monoamniotic pregnancies were excluded. Severity of TTTS was assessed using the Quintero staging system. All vascular anastomoses were endoscopically identified and classified as AVDR (AV from donor to recipient), AVRD (AV from recipient to donor), arterio-arterial (AA), or veno-venous (VV). The surgical procedure was coded as SQLPCV if all AVDRs were lasered first. Outcome measures included intrauterine fetal demise and perinatal survival. Results. One hundred and ninety-three TTTS patients (137 SQLPCV, 56 SLPCV) underwent surgery from May 2003 to August 2005. Gestational age at surgery or at delivery, Stage, patent anastomoses, or persistent/reverse TTTS were not different between the groups. IUFD-D was significantly lower in the SQLPCV than in the SLPCV group (7.3% vs 21.4%, respectively, p = 0.005). Dual perinatal survival was significantly higher in the SQLPCV than in the SLPCV group (73.7% vs 57.1%, respectively, p = 0.02), although the incidence of at least one survivor was not different between the groups (90.5% vs 87.5%, respectively). Logistic regression showed SQLPCV, but not placental location, operating time or number of anastomoses to be significantly associated with a decreased likelihood of IUFD-D (p = 0.007). Conclusion. SQLPCV is associated with a decreased likelihood of IUFD-D and an increased rate of dual survivors compared to SLPCV. SQLPCV represents both an anatomical and functional surgical approach to the laser treatment of twin–twin transfusion syndrome.

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.

Transabdominal intra-amniotic endoscopic assessment of previable premature rupture of membranes.

OBJECTIVE Our purpose was to describe the endoscopic characteristics of the site of rupture in vivo in patients with spontaneous premature rupture of membranes. STUDY DESIGN Patients with preterm premature rupture of membranes between 16 and 26 weeks of gestation, without evidence of intra-amniotic infection, and with a normal karyotype underwent transabdominal endoscopic examination of the amniotic cavity. Subsequently, an amniopatch of a combination of platelets and cryoprecipitate to seal the membrane defect was administered. The study was approved by the Institutional Review Board of St. Josephs Hospital in Tampa, Florida, and all patients gave written informed consent. RESULTS Four patients underwent endoscopic examination and amniopatch administration; three had spontaneous preterm premature rupture of membranes, and in the other the membranes ruptured after an early amniocentesis. The location of the site of rupture was over the internal os in the 3 cases with spontaneous preterm premature rupture of membranes. This area was normal in the patient with iatrogenic preterm premature rupture of membranes. The longer the time between preterm premature rupture of membranes and fetoscopy, the larger and less defined was the site of rupture. The amniopatch restored amniotic integrity for a maximum of 72 hours. CONCLUSIONS This is the first in vivo endoscopic visualization of the site of spontaneous rupture of membranes from within the uterine cavity. The defect is located over the internal cervical os in patients with spontaneous preterm premature rupture of membranes. There appear to be time-related changes in the morphologic characteristics of the site of rupture. Endoscopic visualization of the site of rupture has the potential for improving our understanding of spontaneous preterm premature rupture of membranes and in the development of possible therapeutic alternatives.

Fetal growth after laser therapy for twin-twin transfusion syndrome

OBJECTIVE The objective of the study was to compare twin weight discordance and prevalence of intrauterine growth restriction (IUGR) before laser therapy and after birth in pregnancies complicated by twin-twin transfusion syndrome (TTTS). STUDY DESIGN Women with TTTS who underwent laser therapy with dual neonatal survivors born at least 28 days after surgery were studied. Estimated fetal weight (EFW) discordance at the preoperative sonogram and birthweight (BW) discordance were calculated. Weights below gestational age-corrected 10th percentile at sonogram and at birth for each twin were designated as IUGR. RESULTS Among 211 women studied, the mean EFW discordance measured 26.6% and mean BW discordance was 18.4%, yielding a mean 8.2% decrease in weight discordance (P < .001). Comparing IUGR diagnoses before surgery and at birth, the recipients proportion was unchanged (9.5% vs 7.1%, P = .353), whereas the donors proportion decreased (64.5% vs 28.9%, P < .001). CONCLUSION Twin weight discordance and donor fetus IUGR appear to improve after laser therapy for TTTS.

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.

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

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).

In vitro laser welding of amniotic membranes

To test in vitro the feasibility of welding amniotic membranes using Nd:YAG laser energy.

Percent absent end‐diastolic velocity in the umbilical artery waveform as a predictor of intrauterine fetal demise of the donor twin after selective laser photocoagulation of communicating vessels in twin–twin transfusion syndrome

Absent end‐diastolic velocity (AEDV) in the umbilical artery of the donor twin is a known risk factor for intrauterine fetal demise (IUFD) of this fetus after selective laser photocoagulation of communicating vessels (SLPCV) for twin–twin transfusion syndrome (TTTS). The aim of this study was to assess the proportion of time, expressed as a percentage, of the cardiac cycle spent in AEDV (%AEDV) as a predictor of IUFD of the donor.