Distribution of iliac veins posterior to the common iliac artery bifurcation related to pelvic lymphadenectomy: A digital in vivo anatomical study of 442 Chinese females

Anatomy of the internal iliac vein around the sacral promontory based on CT three-dimensional (3D) reconstruction

INTRODUCTION AND HYPOTHESIS

The area around the sacral promontory (SP) is the targeted location of various pelvic operations. We examined the internal iliac vein (IIV) configurations around the SP by computed tomography angiography (CTA) three-dimensional (3D) reconstruction to describe its anatomy and provide accurate anatomical parameters for relevant operations to reduce intraoperative vascular injury.

METHODS

We retrospectively studied 2078 CTA 3D model datasets from Nanfang Hospital patients examined for gynecological diseases from December 2009 to October 2020. The IIVs of the above cases were divided into standard and variant IIVs, and variant IIVs were subdivided into different subtypes. To compare the size of the avascular area around the SP between standard and variant IIVs, we selected the two subtypes with the highest variation rate for comparison with the standard IIV type.

RESULTS

The most common types of variant IIVs were 5a (5.15%) and 3a (5.05%). The results showed larger values in the standard group than in the 3a and 5a groups for the confluence of common iliac vein (CCIV) height (37.73±12.05 vs. 28.93±10.17 vs. 27.27±7.58 mm, P < 0.05), distance between the iliac vessels (49.47±9.47 mm vs. 37.08±9.36 vs. 37.73±8.94 mm, P < 0.05), and SP exposure width (44.94±6.39 mm vs. 36.83±8.29 vs. 36.93±7.91, P < 0.05).

CONCLUSIONS

Variant IIVs may increase the risk of surgery by reducing the avascular area compared with standard IIVs. Therefore, when operating around the SP, special attention should be given to variant IIVs and avoiding vascular injury.

Three-Dimensional in Vivo Anatomical Study of Female Iliac Vein Variations

OBJECTIVE

To investigate female iliac vein variations by using the computed tomography angiography (CTA) three-dimensional (3 D) reconstruction technique.

METHODS

We retrospectively studied 1623 patients undergoing abdominal and pelvic CTA scanning for gynecological diseases from December 2009 to December 2018. Accurate digital 3 D models of the iliac vein were constructed using Mimics 19.0 software and used to study the morphology and variations. Variations in the common iliac vein (CIV), external iliac vein (EIV) and internal iliac vein (IIV) were classified as type I, abnormal number of veins; type II, abnormal communicating branches; or type III, other variations.

RESULTS

The overall variation rates of the iliac vein and CIV were 51.57% (837/1623) and 20.33% (330/1623), respectively. The main type of CIV variation was type II. The main type I CIV variation was the absence of the CIV (98.15%), which mostly occurred on the right side (64.81%, 35/54). Type II CIV variation was the most common, with abnormal communicating branches between the left CIV and right IIV (81.78%, 211/258). The overall variation rates of the EIV and IIV were 36.66% (595/1623) and 49.60% (805/1623), respectively, mainly on the right side. The main type of variation was type I. Among them, the division of the IIV into two branches plus convergence with the ipsilateral EIV was the most common (22.98%, 373/1623).

CONCLUSION

In this study, approximately half of the patients had iliac vein variations. The preoperative identification of iliac vein variation may reduce vascular injury in pelvic surgery.

3D Patient-Specific Virtual Models for Presurgical Planning in Patients with Recto-Sigmoid Endometriosis Nodules: A Pilot Study

Background and Objective: In recent years, 3D printing has been used to support surgical planning or to guide intraoperative procedures in various surgical specialties. An improvement in surgical planning for recto-sigmoid endometriosis (RSE) excision might reduce the high complication rate related to this challenging surgery. The aim of this study was to build novel presurgical 3D models of RSE nodules from magnetic resonance imaging (MRI) and compare them with intraoperative findings. Materials and Methods: A single-center, observational, prospective, cohort, pilot study was performed by enrolling consecutive symptomatic women scheduled for minimally invasive surgery for RSE between November 2019 and June 2020 at our institution. Preoperative MRI were used for building 3D models of RSE nodules and surrounding pelvic organs. 3D models were examined during multi-disciplinary preoperative planning, focusing especially on three domains: degree of bowel stenosis, nodule’s circumferential extension, and bowel angulation induced by the RSE nodule. After surgery, the surgeon was asked to subjectively evaluate the correlation of the 3D model with the intra-operative findings and to express his evaluation as “no correlation”, “low correlation”, or “high correlation” referring to the three described domains. Results: seven women were enrolled and 3D anatomical virtual models of RSE nodules and surrounding pelvic organs were generated. In all cases, surgeons reported a subjective “high correlation” with the surgical findings. Conclusion: Presurgical 3D models could be a feasible and useful tool to support surgical planning in women with recto-sigmoidal endometriotic involvement, appearing closely related to intraoperative findings.

Variant formation of left common iliac vein by the confluence of four veins

Common iliac vein variations are relatively rare compared to the variations of external and internal iliac veins. A rare pattern of formation of common iliac vein by the confluence of four veins is being reported here. The left common iliac vein was formed by the union of left external iliac vein, internal iliac vein, iliolumbar vein and a common trunk formed by the obturator and vesical veins. External iliac vein and obturator veins were connected by a communicating vein. Both external and common iliac veins were respectively medial to the external and common iliac arteries. Knowledge of this variant formation of common iliac vein could be useful to radiologists, gynecologists and orthopedic surgeons.

Pelvic Lymphadenectomy in Gynecologic Oncology-Significance of Anatomical Variations

Pelvic lymphadenectomy is a common surgical procedure in gynecologic oncology. Pelvic lymph node dissection is performed for all types of gynecological malignancies to evaluate the extent of a disease and facilitate further treatment planning. Most studies examine the lymphatic spread, the prognostic, and therapeutic significance of the lymph nodes. However, there are very few studies describing the possible surgical approaches and the anatomical variations. Moreover, a correlation between anatomical variations and lymphadenectomy in the pelvic region has never been discussed in medical literature. The present article aims to expand the limited knowledge of the anatomical variations in the pelvis. Anatomical variations of the ureters, pelvic vessels, and nerves and their significance to pelvic lymphadenectomy are summarized, explained, and illustrated. Surgeons should be familiar with pelvic anatomy and its variations to safely perform a pelvic lymphadenectomy. Learning the proper lymphadenectomy technique relating to anatomical landmarks and variations may decrease morbidity and mortality. Furthermore, accurate description and analysis of the majority of pelvic anatomical variations may impact not only gynecological surgery, but also spinal surgery, urology, and orthopedics.

Reconstruction of three-dimensional vascular models for lymphadenectomy before surgery

Introduction: A three-dimensional (3D) model of the pelvic vessels was reconstructed before surgery to aid in the understanding of the individual anatomy and help guide lymphadenectomy performance.Material and methods: Thirty patients with early-stage cervical cancer who were scheduled for lymphadenectomy at Nanfang Hospital, Southern Medical University from January 2017 to June 2017 were included. Three-dimensional models of the pelvic vessels were obtained.Results: All 3D models of the 30 patients were reconstructed successfully and were consistent with the operative findings.The most common structural types posterior to the common iliac artery (CIA) and CIA bifurcation (CIAB) were non-vessel structures (23/30 patients) and the common iliac vein (CIV) (27/30); these were observed separately on the left pelvic vein. The confluence of common iliac vein (CCIV) (29/30) and CIV (20/30) were most commonly observed posterior to the CIA and CIAB; these were observed separately on the right pelvic vein. Venous abnormalities were identified in 15 patients. There were variants in venous confluence shown to be homolateral to the CIV (2/15) and contralateral to the CIV (2/15) and CCIV (4/15).Conclusions: Three-dimensional models of the pelvic vessels can provide information on individual anatomy features that can help guide lymphadenectomy performance.

Things may not go as planned: The role of aortoiliac dilation and elongation during the estimation vascular structures' anatomical course

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Variation of aortic morphology such as aortic dimensions, branching points, and correlation with adjacent structures is highlighted.

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The mechanism of variance relies on the diseases such as arteriosclerosis, syphilis and hypertension.

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Patients with hypertension, atherosclerosis, and aortic aneurysm should be excluded from the study because of the variation of aortic morphology is concluded.