Faculty Bibliography

BACKGROUND:Reliable measurement of intraoperative blood loss remains a serious challenge during correction of craniosynostosis. This study analyzed the relationship between estimated blood loss (EBL) and calculated blood loss (CBL) in fronto-orbital advancement and its implications on blood transfusion practice and hospital length of stay (LOS). METHODS:The authors reviewed infants who underwent primary fronto-orbital advancement for craniosynostosis (1997-2009). Estimated blood loss was based on anesthesia records and CBL by preoperative/postoperative hemoglobin. Perioperative red blood cell transfusion (RCT) and hospital LOS were recorded. RESULTS:Ninety infants were included. Mean EBL was 42.2% of estimated blood volume (% EBV), and CBL was 39.3% EBV, without significant difference (P = 0.23). Bland-Altman analysis revealed that EBL was greater than CBL at lower levels of blood loss (≤47.0% EBV) and less than CBL at higher levels (>47.0% EBV). Mean intraoperative RCT was 45.8% EBV; overtransfusion was more frequent at lower levels of bleeding, and undertransfusion at higher levels. Postoperative RCT occurred more frequently with greater blood loss. Mean LOS was 3.7 days, increasing with CBL (hazard ratio of discharge, HR(discharge) = 0.988, P < 0.01), postoperative RCT (HR(discharge) = 0.96, P < 0.05), total RCT (HR(discharge) = 0.991, P < 0.05), and total intraoperative fluid (HR(discharge) = 0.999, P < 0.05). CONCLUSIONS:Estimated blood loss is a less accurate marker for CBL at the extremes of blood loss during fronto-orbital advancement. The tendency to overestimate blood loss with less intravascular volume loss can result in unnecessary transfusion, whereas underestimation with greater actual blood loss can lead to delay in resuscitation and longer hospitalization.

OBJECT/OBJECTIVE:Controlled hypotension is routinely used during open repair of craniosynostosis to decrease blood loss, although this benefit is unproven. In this study the authors analyzed the longitudinal relationships between intraoperative mean arterial pressure (MAP) and calculated blood loss (CBL) during frontoorbital advancement (FOA) for craniosynostosis. METHODS:The authors reviewed the records of infants with craniosynostosis who had undergone primary FOA between 1997 and 2009. Anesthesia records provided preoperative and serial intraoperative MAP. Interval measures of CBL had been determined during the course of the operation. The longitudinal relationships between MAP(mean), MAP(change), and CBL(change) were assessed over the same time interval and compared between adjacent time intervals to determine the directionality of associations. RESULTS:Ninety infants (44 males and 46 females) underwent FOA at a mean age and weight of 10.7 ± 12.9 months and 9.0 ± 7.0 kg, respectively. The average intraoperative MAP was 56.1 ± 4.8 mm Hg, 22.6 ± 12.1% lower than preoperative baseline. A negative correlation was found between CBL(change) and MAP(mean) over the same interval (r = -0.31, p < 0.05), and an inverse relationship was noted between CBL(change) of the previous interval and MAP(change) of the next interval (r = -0.07, p < 0.05). Finally, there was no significant association between MAP(change) of the previous interval and CBL(change) of the next interval. CONCLUSIONS:Calculated blood loss demonstrated a negative correlation with MAP during FOA. Directionality testing indicated that MAP did not affect intraoperative blood loss; instead, blood loss drove changes in MAP. Overall, these findings challenge the benefit of controlled hypotension during open craniofacial repair.

BACKGROUND:Blood loss during fronto-orbital advancement (FOA) remains a significant potential source of morbidity. This study explored variables that might correlate with calculated blood loss (CBL) during this procedure. METHODS:The authors reviewed infants with craniosynostosis who underwent primary FOA (1997-2009). Patient demographics, operative time, and mean arterial pressure (MAP) were recorded. Serial MAPs were averaged for a MAPmean and subtracted from preoperative baseline to calculate MAP%decrease. This provided indicators of both absolute and relative hypotension, respectively. Calculated blood loss was based on preoperative/postoperative hemoglobin values and transfusion volumes and accounted for hemodilutional effects. RESULTS:Ninety infants underwent FOA at an average age of 10.7 ± 12.9 months and mean weight of 9.0 ± 7.0 kg. Average operative time was 4.2 hours, and intraoperative MAP was 56.1 mm Hg, 22.6% lower than baseline. Mean CBL was 259.3 mL, or 39.3% of estimated blood volume, negatively correlating with surgical age (r = -0.033, P < 0.05) and positively trending with operative time (r = 0.55, P < 0.05). Absolute hypotension was associated with greater blood loss, as demonstrated by an inverse relationship between CBL and MAPmean (r = -0.19, P < 0.05). From the perspective of relative hypotension, no association was found between CBL and MAP%decrease. CONCLUSIONS:Greater operative efficiency and deferring operative correction to a later age may diminish blood loss during FOA. The study results also raise serious concerns regarding the hemodynamic benefits of controlled systemic hypotension.

OBJECT/OBJECTIVE:Intraoperative blood loss represents a significant concern during open repair of craniosynostosis, and its reliable measurement remains a serious challenge. In this study of extended sagittal synostectomies, the authors analyzed the relationship between estimated blood loss (EBL) and calculated blood loss (CBL), and investigated predictors of hemodynamic outcomes. METHODS:The authors reviewed outcomes in infants with sagittal synostosis who underwent primary extended synostectomies (the so-called Pi procedure) between 1997 and 2009. Patient demographic data, operating time, and mean arterial pressures (MAPs) were recorded. Serial MAPs were averaged for a MAP(mean). The EBL was based on anesthesia records, and the CBL on pre- and postoperative hemoglobin values in concert with transfusion volumes. Factors associated with EBL, CBL, red blood cell transfusion (RBCT), and hospital length of stay (LOS) were investigated. Hemodynamic outcomes were reported as percent estimated blood volume (% EBV), and relationships were analyzed using simple and multiple linear and logistic regression models. A p value < 0.05 was considered significant. RESULTS:Seventy-one infants with sagittal synostosis underwent primary extended synostectomies at a mean age and weight of 4.9 months and 7.3 kg, respectively. The average operating time was 1.4 hours, and intraoperative MAP was 54.6 mm Hg (21.3% lower than preoperative baseline). There was no association between mean EBL (12.7% EBV) and mean CBL (23.6% EBV) (r = 0.059, p = 0.63). The EBL inversely correlated with the patient's age (r = -0.07) and weight (r = -0.11) at surgery (p < 0.05 in both instances). With regard to intraoperative factors, EBL positively trended with operating time (r = 0.26, p = 0.09) and CBL inversely trended with MAP(mean) (r = -0.04, p = 0.10), although these relationships were only borderline significant. Intraoperative RBCT, which was required in 59.1% of patients, positively correlated with EBL (r = 1.55, p < 0.001), yet negatively trended with CBL (r = -0.40, p = 0.01). Undertransfusion was significantly more common than overtransfusion (40.8% vs 22.5%, p = 0.02, respectively). The mean hospital LOS was 2.3 days and was not significantly associated with patient demographic characteristics, intraoperative factors, blood loss, RBCT, or total fluid requirements. CONCLUSIONS:In extended synostectomies for sagittal synostosis, EBL and CBL demonstrated a decided lack of correlation with one another. Intraoperative blood transfusion positively correlated with EBL, but inversely correlated with CBL, with a significantly higher proportion of patients undertransfused than overtransfused. These findings highlight the need for reliable, real-time monitoring of intraoperative blood loss to provide improved guidance for blood and fluid resuscitation.

BACKGROUND:The purpose of this study was to critically assess long-term outcomes after open reconstruction of craniosynostosis within the recent decade. METHODS:The authors performed a retrospective, institutional review board-approved review of open repair for craniosynostosis between 1997 and 2009. Surgical factors, complications, and long-term outcomes were assessed. Pearson chi-square, Fisher's exact, and Kaplan-Meier analyses were performed. RESULTS:Of 212 patients, 72 underwent primary extended synostectomy and 140 had traditional open craniofacial repair. Mean follow-up was 36.3 months (range, 0.5 to 138 months). Indications included sagittal (n = 96), metopic (n = 40), unicoronal (n = 33), bicoronal (n = 24), multisutural (n = 15), bilambdoidal (n = 3), and unilambdoidal (n = 1) synostoses; 8.5 percent of patients were syndromic. Surgical reconstruction was performed at a mean age of 11.3 months (range, 0.2 to 117.8 months), including nonsyndromic patients at an average age of 10.6 months and syndromic patients at age 19.3 months. There were no deaths. A 3.3 percent complication rate included two cerebral contusions, two hematomas, one cerebrospinal fluid leak, one infection, and one wound breakdown. Patients were categorized as 89.2 percent Whitaker class I/II and 10.8 percent Whitaker class III/IV. Major and total reoperation rates were 9.0 percent and 10.8 percent, respectively. Higher total reoperation rate and Whitaker class III/IV distribution significantly correlated with syndromic diagnosis, bicoronal synostosis, and surgical age younger than 6 months. CONCLUSIONS:In this experience of contemporary open craniosynostosis surgery, rates of morbidity, mortality, and reoperation were low. These results support the merits of surgical delay, targeting an age of 6 months or older, and may serve as a more accurate metric of comparison to current minimally invasive techniques for craniosynostosis repair.