Pelvimetry Data Research Articles

The impact of pelvimetry data on rectal cancer surgery—a systematic review

The impact of pelvimetry data on rectal cancer surgery—a systematic review

X-ray Pelvimetry Has No Impact on the Outcomes of Trial of Labor after Cesarean Delivery: A Retrospective Single-center Study.

Few studies have examined the relationship between pelvic size and the success or failure of trial of labor after cesarean delivery (TOLAC). Here we aimed to determine whether pelvic size and morphological data obtained from radiography contribute to the first successful TOLAC. This retrospective single-center observational study enrolled pregnant women who underwent TOLAC between 2010 and 2021. The results of X-ray pelvimetry data, including obstetric conjugate (OC), transverse diameter of the pelvic inlet (TD), anteroposterior diameter of the pelvic inlet (APD), shape of the pelvic inlet, and other obstetrical clinical data, were compared between the success and failure groups. Seventy-five patients in successful group after excluding 35 patients with previous successful TOLAC, and 21 patients in failure group were eligible. The failure group had a higher rate of previous cesarean sections due to failed labor trials (p = 0.042) and heavier newborns (p = 0.014). OC, TD, and APD on X-ray pelvimetry did not differ significantly between the two groups nor did the shape of the pelvic inlet affect the success rate for TOLAC. The generalized linear model identified a history of failed trials of labor as a significant predictor of failed TOLAC (odds ratio, 0.26; 95% confidence interval 0.071-0.923; p = 0.037), whereas no pelvimetric parameters were found. Pelvic size and morphological findings have no discernible impact on the outcomes of TOLAC. The universal application of X-ray pelvimetry in all women attempting TOLAC may not have significant clinical relevance.

Mesorectal fat area as a useful predictor of the difficulty of robotic-assisted laparoscopic total mesorectal excision for rectal cancer.

Various predictors of the difficulty of total mesorectal excision for rectal cancer have been described. Although a bulky mesorectum was considered to pose technical difficulties in total mesorectal excision, no studies have evaluated the influence of mesorectum morphology on the difficulty of total mesorectal excision. Mesorectal fat area at the level of the tip of the ischial spines on magnetic resonance imaging was described as a parameter characterizing mesorectum morphology. This study aimed to evaluate the influence of clinical and anatomical factors, including mesorectal fat area, on the difficulty of total mesorectal excision for rectal cancer. This study enrolled 98 patients who underwent robotic-assisted laparoscopic low anterior resection with total mesorectal excision for primary rectal cancer, performed by a single expert surgeon, between 2010 and 2015. Magnetic resonance imaging-based pelvimetry data were collected. Linear regression was performed to determine clinical and anatomical factors significantly associated with operative time of the pelvic phase, which was defined as the time interval from the start of rectal mobilization to the division of the rectum. The median operative time of the pelvic phase was 68min (range 33-178min). On univariate analysis, the following variables were significantly associated with longer operative time of the pelvic phase: male sex, larger tumor size, larger visceral fat area, larger mesorectal fat area, shorter pelvic outlet length, longer sacral length, shorter interspinous distance, larger pelvic inlet angle, and smaller angle between the lines connecting the coccyx to S3 and to the inferior middle aspect of the pubic symphysis. On multiple linear regression analysis, only larger mesorectal fat area remained significantly associated with longer operative time of the pelvic phase (p = 0.009). Mesorectal fat area may serve as a useful predictor of the difficulty of total mesorectal excision for rectal cancer.

Pelvimetry in Squirrel Monkeys (Saimiri scireus Linnaeus, 1758)

ABSTRACT: Saimiri sciureus is a neotropical primate widely used in research. However, there are still difficulties regarding their reproduction in vivaria due to the high incidence of dystocia. Dystocia in primates can be caused by cephalopelvic disproportion and in Squirrel Monkeys, pregnancy of large fetuses were reported. This paper describes pelvimetry data of adult females and subadults in specimens of Squirrel Monkeys, from a research colony of Para, Brazil. Pelvic radiographs were obtained in ventrodorsal projections and the following measurements were taken: superior bi-iliac diameter (SBID); inferior bi-iliac diameter (IBID); bi-iliac average diameter (BIAD); right diagonal diameter (RDD); left diagonal diameter (LDD); sacro-pubic diameter (SPD); Based on the obtained diameters, the entrance area of the pelvis (EAP) was also calculated. The average values of the pelvic diameters and EAP in adult females were SBID 1.714cm, BIAD 1.957cm, IBID 1.686cm, RDD 2.771cm, LDD 2.764cm, SPD 2.543cm and EAP 3.9056cm2; and subadult females: 1.588cm SBID, 1.850cm BIAD, 1.625cm IBID, 2.50cm RDD, LDD 2.474cm, 1.95cm SPD and 2.8293 cm2 EAP. Saimiri sciureus pelvis is characterized as dolichopelvic. There was statistical significance between the values for adult females and subadults to SBID, BIAD, RDD, LDD, SPD and EAP. The values of SBID and IBID were lower when compared to the published data for the same species. The result found on this paper will serve as a basis for future studies using pelvic measurements and dystocia prediction of neotropical primates and comparison between different vivaria.

Cartilage formation in the pelvic skeleton during the embryonic and early-fetal period.

The pelvic skeleton is formed via endochondral ossification. However, it is not known how the normal cartilage is formed before ossification occurs. Furthermore, the overall timeline of cartilage formation and the morphology of the cartilage in the pelvis are unclear. In this study, cartilage formation in the pelvic skeletons of 25 human fetuses (crown-rump length [CRL] = 11.9–75.0 mm) was observed using phase-contrast computed tomography and 7T magnetic resonance imaging. The chondrification center of the ilium, ischium, and pubis first appeared simultaneously at Carnegie stage (CS) 18, was located around the acetabulum, and grew radially in the later stage. The iliac crest formed at CS20 while the iliac body’s central part remained chondrified. The iliac body formed a discoid at CS22. The growth rate was greater in the ilium than in the sacrum-coccyx, pubis, and ischium. Connection and articulation formed in a limited period, while the sacroiliac joint formed at CS21. The articulation of the pubic symphysis, connection of the articular column in the sacrum, and Y-shape connection of the three parts of the hip bones to the acetabulum were observed at CS23; the connection of the ischium and pubic ramus was observed at the early-fetal stage. Furthermore, the degree of connection at the center of the sacrum varied among samples. Most of the pelvimetry data showed a high correlation with CRL. The transverse and antero-posterior lengths of the pelvic inlet of the lesser pelvis varied among samples (R2 = 0.11). The subpubic angle also varied (65–90°) and was not correlated with CRL (R2 = 0.22). Moreover, cartilaginous structure formation appeared to influence bone structure. This study provides valuable information regarding the morphogenesis of the pelvic structure.

CT/MRI pelvimetry as a useful tool when selecting patients with rectal cancer for transanal total mesorectal excision.

The quality of a total mesorectal excision (TME) is one of the most important prognostic factors for local recurrence of rectal carcinoma. The aim of this study was to clarify the manner in which lesser pelvis dimensions affect the quality of TME via the transabdominal approach, while simultaneously defining the criteria for selecting patients most likely to have Grade 3 TME outcomes for a transanal approach using the TaTME technique. An analysis from the registry was conducted using 93 of total 198 patients with rectal cancer of the mid- and lower third of the rectum who underwent: (1) a low anterior resection, (2) an ultra-low resection with coloanal anastomosis, or (3) an intersphincteric rectal resection, all with total mesorectal excision. The procedures were carried out at the Department of Surgery at the University Hospital Hradec Králové between 2011 and 2014. Rectal specimens were histopathologically examined according to a standardized protocol. Pelvimetry data were obtained using anteroposterior, transverse, and sagittal CT or MRI scans. A correlation was found between the quality of the TME and pelvimetry parameter A5, i.e., the angle between the longitudinal axis of the symphysis, and the lines between the symphysis and the promontory (R(2) = -0.327, p < 0.001). The ordinal regression method was used to identify parameters of the model describing levels of probability for TME quality. These relationships were described by equations that provide probability of the achievement of each grade of TME. The correlation described by obtained equations between pelvimetry parameters and the quality of TME represents a new tool for use in preoperative decision-making with regard to resection via the transanal approach (TaTME).

Détection des disproportions fœtopelviennes par réalité virtuelle : étude de faisabilité à propos de trois cas

Routine daily practice shows that successful vaginal delivery for women with suspected narrow pelvis or large fetus remains possible. We present a computer software for the detection of fetopelvic disproportion based on 3D vectorial reconstructions of the fetal head and maternal pelvis with simulation of head passage through the pelvis for collision detection. Three delivery simulations were generated from MR pelvimetry data in two patients, one with narrow pelvis and the other with macrosomic fetus. Based on the simulation, fetus size in both cases was appropriate for the pelvic size, but delivery simulation for the macrosomic fetus concluded that vaginal delivery was mechanically impossible. Further evaluation of this promising software on a larger patient population is necessary.

Senkt die Kombination von fetaler Biometrie und MRT-Pelvimetrie die Rate an sekundären Sectiones?

Cephalopelvic disproportion (CPD) is a frequent indication for secondary Caesarean section. The delivery simulation software Anapelvis was developed to predict a CPD on the basis of foetal ultrasound biometry and maternal pelvimetry data. The objective of this retrospective study was to analyse the predictive value of Anapelvis software in consideration of antenatal foetal biometry quality. 162 pregnant women with suspected CPD who had undergone a magnetic resonance imaging pelvimetry were included in this study. The antenatal foetal biometry was carried out within a week before delivery. The positive predictive value (PPV) for arrest of delivery was 85.7% in the group of 79 pregnancies with planned vaginal delivery. Sensitivity was 56.3%, specificity 60.0% and negative predictive value (NPV) 24.3% accordingly. The highest accuracy [percent error (PE) -0.1%] of fetal weight estimation was found in the group where an arrest of delivery was predicted. The lowest accuracy (PE -4.4%) was detected in the group with the prediction of vaginal delivery. Labour simulation software can be helpful only in such cases where an arrest of delivery was predicted. The accuracy of delivery simulation with the Anapelvis software was considerably affected by the quality of antenatal foetal ultrasound biometry.

Factors Influencing Pathologic Results after Total Mesorectal Excision for Rectal Cancer: Analysis of Consecutive 100 Cases

The aim of this study was to analyze clinical and anatomical factors affecting the pathologic quality of the resected specimen after total mesorectal excision (TME) for rectal cancer. A total of 100 patients who underwent TME for mid or low rectal cancer were evaluated prospectively. MRI pelvimetry data (transverse diameter, obstetric conjugate, interspinous distance, sacrum length, and sacrum depth) were analyzed as anatomically affecting factors to postoperative specimen quality. Sex, body mass index (BMI), type of surgery, tumor size, and tumor distance from the anal verge were analyzed as clinically affecting factors. The gross judgment of resected specimen, circumferential resection margin and the number of harvested lymph nodes were used to access postoperative specimen quality. The univariate and multivariate analysis showed that narrow obstetric conjugate and shorter interspinous distance were related to the inadequate quality of the mesorectum in the specimen (P = 0.022, P = 0.030). Interspinous distance was a predicting factor of a positive circumferential resection margin (P = 0.007). There were no clinical factors affecting the inadequate quality of the mesorectum or positive circumferential resection margin. Moreover, there were no clinico-anatomical factors affecting the number of harvested lymph nodes after TME. Narrow obstetric conjugate and shorter interspinous distance were factors leading to poor postoperative specimen quality. Rectal cancer patients with narrow obstetric conjugate or shorter interspinous distance should be considered as high-risk patients with regard to specimen quality, which is in turn related to oncological outcome.

Vaginal birth after cesarean section: X-ray pelvimetry at term is informative

To examine whether X-ray pelvimetry data to evaluate the likelihood of vaginal birth after previous cesarean section. Retrospective study. University hospital. Patients with a previous cesarean delivery who underwent X-ray pelvimetry and gave birth at gestational age 37 weeks during a seven-year period. 1190 patients with a scarred uterus were compared with 15,189 patients without a scarred uterus. In the scarred uterus group, 760 patients with a transverse pelvic diameter > or =12 cm were compared with 430 patients with a transverse pelvic diameter <12 cm. The obstetrical outcomes were spontaneous or induced labor, and mode of delivery. The maternal morbidity outcomes were hemorrhage requiring transfusion of packed red cells, uterine rupture, bladder injury, and hysterectomy due to hemorrhage. The neonatal morbidity outcomes were the 5-min Apgar score, transfer to intensive care, and intubation. Patients with a scarred uterus had a significantly higher rate of cesarean section (35.5%) than those with no prior cesarean section (9%). Among patients with a scarred uterus who were selected for vaginal delivery, 81% delivered vaginally when the transverse diameter (TD) of the pelvic inlet was greater than 12 cm, 68% when the TD was between 11.5 and 12 cm, and 58% when the TD was less than 11.5 cm. Maternal morbidity was significantly higher in the patients with a scarred uterus. The neonatal results were comparable in the different groups. X-ray pelvimetry tailors the information given to each patient about the likelihood of having a vaginal delivery. It can also be used to optimize the selection of patients allowed to enter labor.

Vaginal birth after cesarean section: X-ray pelvimetry at term is informative

Objective To examine whether X-ray pelvimetry data to evaluate the likelihood of vaginal birth after previous cesarean section. Design Retrospective study. Setting University hospital. Population Patients with a previous cesarean delivery who underwent X-ray pelvimetry and gave birth at gestational age 37 weeks during a seven-year period. Methods 1190 patients with a scarred uterus were compared with 15,189 patients without a scarred uterus. In the scarred uterus group, 760 patients with a transverse pelvic diameter > or =12 cm were compared with 430 patients with a transverse pelvic diameter Main outcome measures The obstetrical outcomes were spontaneous or induced labor, and mode of delivery. The maternal morbidity outcomes were hemorrhage requiring transfusion of packed red cells, uterine rupture, bladder injury, and hysterectomy due to hemorrhage. The neonatal morbidity outcomes were the 5-min Apgar score, transfer to intensive care, and intubation. Results Patients with a scarred uterus had a significantly higher rate of cesarean section (35.5%) than those with no prior cesarean section (9%). Among patients with a scarred uterus who were selected for vaginal delivery, 81% delivered vaginally when the transverse diameter (TD) of the pelvic inlet was greater than 12 cm, 68% when the TD was between 11.5 and 12 cm, and 58% when the TD was less than 11.5 cm. Maternal morbidity was significantly higher in the patients with a scarred uterus. The neonatal results were comparable in the different groups. Conclusion X-ray pelvimetry tailors the information given to each patient about the likelihood of having a vaginal delivery. It can also be used to optimize the selection of patients allowed to enter labor.

Randomised Controlled Trial of Magnetic-Resonance Pelvimetry in Breech Presentation at Term

Summary Background Pelvimetry is widely used in women with breech presentation at term to select those for whom planned vaginal delivery is appropriate. However, its clinical value has never been established. We evaluated pelvimetry in a randomised controlled trial. The main outcome measures were the elective and emergency caesarean-section rates and the early condition of the neonate. Methods Magnetic-resonance (MR) pelvimetry was done on 235 women. The women were then randomly assigned to two groups–for the study group (n=118), the pelvimetry results were reported to the responsible obstetricians, who used them as the basis for decisions on whether to schedule elective caesarean or trial of labour; for the control group (n=117), the pelvimetry results were not disclosed until 8 weeks post partum, and decisions about obstetric management were made on the basis of clinical factors only. Findings 35 women (15 [13%] study group, 20 [17%] control group) had abnormalities on pelvimetry. The overall caesarean-section rates did not differ significantly between the study and control groups (50 [42%] vs 59 [50%], p=0·24) but the emergency caesarean-selection rate was significantly lower in the study group than in the control group (22 [19%] vs 41 [35%], p=0·0052). The mean 1 min Apgar scores in the study and control groups were 8·1 and 8·0 (p=0·93) and the mean 3 min scores 9·5 and 9·4, respectively (p=0·28). There were no significant differences in the early neonatal outcome for infants born vaginally, by emergency caesarean section, or by elective caesarean section in the two groups, except for a significantly lower Apgar score in the six infants born vaginally to control-group women who had pelvic abnormalities. Interpretation The use of MR pelvimetry in breech presentation at term did not significantly reduce the overall caesarean-section rate. However, it allowed better selection of the delivery route, with a significantly lower emergency caesarean-section rate. Neonatal outcome was not compromised by use of the pelvimetry data.

Randomised controlled trial of magnetic-resonance pelvimetry in breech presentation at term

Pelvimetry is widely used in women with breech presentation at term to select those for whom planned vaginal delivery is appropriate. However, its clinical value has never been established. We evaluated pelvimetry in a randomised controlled trial. The main outcome measures were the elective and emergency caesarean-section rates and the early condition of the neonate. Magnetic-resonance (MR) pelvimetry was done on 235 women. The women were then randomly assigned to two groups--for the study group (n = 118), the pelvimetry results were reported to the responsible obstetricians, who used them as the basis for decisions on whether to schedule elective caesarean or trial of labour; for the control group (n = 117), the pelvimetry results were not disclosed until 8 weeks post partum, and decisions about obstetric management were made on the basis of clinical factors only. 35 women (15 [13%] study group, 20 [17%] control group) had abnormalities on pelvimetry. The overall caesarean-section rates did not differ significantly between the study and control groups (50 [42%] vs 59 [50%], p = 0.24) but the emergency caesarean-section rate was significantly lower in the study group than in the control group (22 [19%] vs 41 [35%], p = 0.0052). The mean 1 min Apgar scores in the study and control groups were 8.1 and 8.0 (p = 0.93) and the mean 3 min scores 9.5 and 9.4, respectively (p = 0.28). There were no significant differences in the early neonatal outcome for infants born vaginally, by emergency caesarean section, or by elective caesarean section in the two groups, except for a significantly lower Apgar score in the six infants born vaginally to control-group women who had pelvic abnormalities. The use of MR pelvimetry in breech presentation at term did not significantly reduce the overall caesarean-section rate. However, it allowed better selection of the delivery route, with a significantly lower emergency caesarean-section rate. Neonatal outcome was not compromised by use of the pelvimetry data.

Pelvimetry by magnetic resonance imaging as a diagnostic tool to evaluate dystocia

To test the clinical value of magnetic resonance imaging (MRI) pelvimetry for the diagnosis of cephalopelvic disproportion. All deliveries from January 1993 through December 1994 were reviewed to identify 42 nulliparas at term with vertex presentation and cesarean delivery due to dystocia. Complete data were available for 41 women, and subjects were divided into the following two subgroups, according to clinical data: "cephalopelvic disproportion" (n = 28) and "failure to progress" (n = 13). Ten nulliparous women with uncomplicated vaginal delivery served as controls. Pelvimetry data from postpartum MRI were correlated with fetal and neonatal dimensions to evaluate various criteria for the diagnosis of cephalopelvic disproportion. Comparing both the fetal head volume derived from antepartum ultrasound assessment and the neonatal head volume (postpartum measurement) with maternal pelvic capacity determined by MRI, cephalopelvic disproportion (head volume exceeding pelvic capacity) indicated that 25 and 27, respectively, of the 28 women had been clinically diagnosed correctly with cephalopelvic disproportion, corresponding to sensitivities of 89% and 96%, respectively. Fetal head volume was not larger than pelvic capacity in any of the women in the control group. In seven of the 13 women diagnosed as "failure to progress," the fetal head volume exceeded the pelvic capacity. A fetal head volume estimate exceeding MRI-measured pelvic capacity is a frequent finding in nulliparas with cesarean birth due to cephalopelvic disproportion. An appropriate prospective study to determine the benefits of an antepartum diagnosis of cephalopelvic disproportion in high-risk nulliparas is warranted.

Radiologic low-dose pelvimetry. Indications and pelvimetry data.

In large patient populations from Karolinska Sjukhuset, radiologic pelvimetry data including mean values and correlation of the pelvic diameters have been defined. Overall incidence of contraction and borderline pelvic measurements and the efficacy of selecting by palpation the patients with a narrow pelvis have been evaluated. The indications for pelvimetry were related to an earlier period. By re-evaluation of the clinical application of pelvimetry a modified routine low-dose pelvimetry is proposed. From measurement of the transverse outlet diameters on an orthodiagraphic a.p. film the sum of the outlet diameters is estimated and a supplementary lateral film is exposed in selected cases. Employing pelvimetry in all primigravidae by the orthodiagraphic a.p. film would still result in a lower total population dose than does the presently used routine of complete pelvimetry, consisting of the same a.p. and lateral films, in selected cases.

OUTCOME OF TERM BREECH DELIVERY IN PRIMIGRAVIDAE. A FETO-PELVIC BREECH INDEX

Analysis of 340 term breech presentations in primigravidas showed a corrected perinatal mortality of 1.5%; the elective cesarean section rate was 15%. The incidence of complicated labour, defined in the study, was analyzed with regard to different parameters, e.g. X-ray pelvimetry data in all 340 cases. Complicated labour in vaginal deliveries markedly increased with increasing fetal weight (p>0.001) and decreasing pelvic capacity (p>0.001). In each case the fetal weight and smallest pelvimetry data were given score points and the sum of these was called the Feto Pelvic Breech Index, which was correlated to the incidence of complicated labour. By using this index the mortality and morbidity probably can be markedly reduced without the routine use of elective cesarean section. The prognostic methods available to detect feto-pelvic disproportion are discussed.

Outcome of term breech delivery in primigravidae. a feto peivicbreech index.

Analysis of 340 term breech presentations in primigravidas showed a corrected perinatal mortality of 1.5%; the elective cesarean section rate was 15%. The incidence of complicated labour, defined in the study, was analyzed with regard to different parameters, e.g. X-ray pelvimetry data in all 340 cases. Complicated labour in vaginal deliveries markedly increased with increasing fetal weight (p less than 0.001) and decreasing pelvic capacity (p less than 0.001). In each case the fetal weight and smallest pelvimetry data were given score points and the sum of these was called the Feto Pelvic Breech Index, which was correlated to the incidence of complicated labour. By using this index the mortality and the routine use of elective cesarean section. The prognostic methods available to detect feto-pelvic disproportion are discussed.

A review of pelvimetry data.

There was little difference between pelvic size in patients referred for pelvimetry and a control group. There were high Caesarian section and forceps rates in pelvimetry patients, and this was seen even if the pelvis was above average in size. It is suggested that moulding of the maternal pelvis is likely to be poor in patients referred for pelvimetry.