Careful Dissection of the Distal Ureter Is Highly Important in Nerve-sparing Radical Pelvic Surgery: A 3D Reconstruction and Immunohistochemical Characterization of the Vesical Plexus

Key Anatomical Concepts, Landmarks, and Proposed Terminology for Nerve-Sparing Gynecologic Surgery: A Narrative Review

OBJECTIVE

To synthesize the terminology utilized in nerve-sparing surgical literature and propose standardized and nonconflicting terms to allow for consistent vocabulary.

DESIGN

We performed a literature search on PubMed using the search terms "pelvis" and "nerve-sparing." Nongynecologic surgery and animal studies were excluded. A narrative review was performed, focusing on nerves, fasciae, ligaments, and retroperitoneal spaces. Terms from included papers were discussed by all authors, who are surgeons versed in nerve-sparing procedures and one anatomist, and recommendations were made regarding the most appropriate terms based on the frequency of occurrence in the literature and the possibility of overlapping names with other structures.

RESULTS

224 articles were identified, with 81 included in the full-text review. Overall, 48% of articles focused on cervical cancer and 26% on deeply infiltrating endometriosis. Findings were synthesized both narratively and visually. Inconsistencies in pelvic anatomical nomenclature were prevalent across publications. The structure with the most varied terminology was the rectal branch of the inferior hypogastric plexus with 14 names. A standardized terminology for pelvic autonomic nerve structures, fasciae, ligaments, and retroperitoneal spaces was proposed to avoid conflicting terms.

CONCLUSION

Surgeons and anatomists should use consistent terminology to facilitate increased uptake of nerve-sparing techniques in gynecologic surgery through a better understanding of surgical technique description. We have proposed a standardized terminology believed to facilitate this goal.

Female near-TME: standardization of proctectomy in women with ulcerative colitis

Traditionally, 2 surgical techniques for proctectomy in ulcerative colitis have been used: total mesorectal excision (TME), and close rectal dissection (CRD). Recently, our research group has proposed the standardization of the Near-TME technique, which unites the advantages of both methods. It decreases the risk of pelvic autonomic nerve injury and reduces the volume of mesorectal remnant. When performing the Near-TME, the anatomical landmarks differ between men and women, especially in the anterolateral hemicircumference. The objective of this paper is to standardize the Near-TME technique in women (Female Near-TME) using characteristic surgical-anatomic landmarks of the female pelvis based on illustrations and a real case treated laparoscopically. This technique should be carried out by surgeons with experience in inflammatory bowel disease surgery and extensive knowledge of surgical anatomy.

The distribution of the inferior hypogastric plexus in female pelvis

Elements that comprise the inferior hypogastric plexus are difficult to expose, intricate, and highly variable and can easily be damaged during local surgical procedures. We aimed to highlight, through dissection, the origin, formation, and distribution of the hypogastric nervous structures and follow them in the female pelvis. We performed detailed dissections on 7 female formalin-fixed cadavers, focusing on structures surrounding the pelvic organs. For each hemipelvis, we removed the peritoneum from the pelvic floor, and after we identified the hypogastric nerves, we continued our dissection towards the inferior hypogastric plexuses, following the branches of the latter. Laterorectally, the hypogastric nerves form the inferior hypogastric plexus, a variable structure - nervous lamina, neuronal network (more frequently), or sometimes a combination of them. We identified three components of the inferior hypogastric plexus. The anterior bundle travels towards the base of the urinary bladder, the middle part innervates the uterus and the vagina, and the posterior segment provides the innervation of the rectum. The plexus can be identified after removing the pelvic peritoneum and the subperitoneal adipose tissue. Intraoperatively, the structures can be preserved by using an immediately-subperitoneal dissection plane. The variable branches are relatively well-organized around the pelvic vessels, supplying the urinary bladder, the genital organs, and the rectum. The ureter is surrounded by some branches, especially in its last segment, and it also receives innervation directly from the hypogastric nerve. Close to the viscera, the nerves enter neurovascular plexuses, making the intraoperative separation of the nerves and the vessels virtually impossible.

Bioengineering solutions for Ureteric disorders: Clinical need, challenges and opportunities

Objectives

To summarise the causes of ureteric damage and the current standard of care, discussing the risks and benefits of available therapeutic options. We then focus on the current and future solutions that can be provided by ureteric bioengineering and provide a description of the ideal characteristics of a bioengineered product.

Methods

We performed a literature search in February 2021 in: Google Scholar, Medline, and Web of Science. Three searches were conducted, investigating: (a) the epidemiology of ureteric pathology, (b) the current standard of care, and (c) the state of the art in ureteric bioengineering.

Results

The most‐common causes of ureteric damage are iatrogenic injury and external trauma. Current approaches to treatment include stent placement or surgical reconstruction. Reconstruction can be done using either urological tissue or segments of the gastrointestinal tract. Limitations include scarring, strictures, and infections. Several bioengineered alternatives have been explored in animal studies, with variations in the choice of scaffold material, cellular seeding populations, and pre‐implantation processing. Natural grafts and hybrid material appear to be associated with superior outcomes. Furthermore, seeding of the scaffold material with stem cells or differentiated urothelial cells allows for better function compared to acellular scaffolds. Some studies have attempted to pre‐implant the graft in the omentum prior to reconstruction, but this has yet to prove any definitive benefits.

Conclusion

There is an unmet clinical need for safer and more effective treatment for ureteric injuries. Urological bioengineering is a promising solution in preclinical studies. However, substantial scientific, logistic, and economic challenges must be addressed to harness its transformative potential in improving outcomes.

Effectiveness and Long-term Outcomes of Nerve-Sparing Radical Hysterectomy for Cervical Cancer

BACKGROUND

Radical hysterectomy (RH) is a type of radical surgery for cervical cancer. Urinary dysfunction due to RH worsens postoperative quality of life of patients with cervical cancer. Nerve-sparing RH (NSRH) technique has been used as an effective means to conserve urinary function. However, few reports have examine long-term outcomes after NSRH. This study describes the details and long-term outcomes of our nerve-sparing technique.

METHODS

Sixty-one patients underwent radical hysterectomy in a 5-year period during which nerve-sparing technique was introduced; of these, 31 patients underwent NSRH and 30 underwent conventional RH. We retrospectively examined their medical records and compared postoperative urinary function and treatment outcomes between these two groups.

RESULTS

The median time required for urinary residual volume to fall to ≤50 mL after removal of the urinary catheter was 6 days (range, 2-20 days) in the NSRH group and 13.5 days (range, 3-46 days) in the RH group. The results were significantly better in the NSRH group (p < 0.05). The mean follow-up period was 2456.3 days (range, 48-4,213 days). Analysis of curability revealed no significant difference between the two groups in local recurrence or long-term survival rates. The 5-year survival rate was 0.861 in the NSRH group and 0.782 in the RH group; the 10-year survival rate was 0.861 in the NSRH group and 0.679 in the RH group.

CONCLUSIONS

NSRH significantly improved postoperative urinary function without worsening local recurrence rates or long-term outcomes.

Nerve-sparing radical hysterectomy in the precision surgery for cervical cancer

Precision cancer surgery is a system that integrates the accurate evaluation of tumor extension and aggressiveness, precise surgical maneuvers, prognosis evaluation, and prevention of the deterioration of quality of life (QoL). In this regard, nerve-sparing radical hysterectomy has a pivotal role in the personalized treatment of cervical cancer. Various types of radical hysterectomy can be combined with the nerve-sparing procedure. The extent of parametrium and vagina/paracolpium excision and the nerve-sparing procedure are tailored to the tumor status. Advanced magnetic resonance imaging technology will improve the assessment of the local tumor extension. Validated risk factors for perineural invasion might guide selecting treatment for cervical cancer. Type IV Kobayashi (modified Okabayashi) radical hysterectomy combined with the systematic nerve-sparing procedure aims to both maximize the therapeutic effect and minimize the QoL impairment. Regarding the technical aspect, the preservation of vesical nerve fibers is essential. Selective transection of uterine nerve fibers conserves the vesical nerve fibers as an essential piece of the pelvic nervous system comprising the hypogastric nerve, pelvic splanchnic nerves, and inferior hypogastric plexus. This method is anatomically and surgically valid for adequate removal of the parametrial and vagina/paracolpium tissues while preserving the total pelvic nervous system. Local recurrence after nerve-sparing surgery might occur due to perineural invasion or inadequate separation of pelvic nerves cutting through the wrong tissue plane between the pelvic nerves and parametrium/paracolpium. Postoperative management for long-term maintenance of bladder function is as critical as preserving the pelvic nerves.

Identification and injury to the inferior hypogastric plexus in nerve-sparing radical hysterectomy

Waterjet dissection of the inferior hypogastric plexus (IHP) resulted in a more rapid return of normal urodynamics than blunt dissection (control group) in patients who received laparoscopic nerve-sparing radical hysterectomy (NSRH) in a randomized controlled study. However, the definite reasons for these results were unknown. This subgroup analysis compared the neural areas and impairment in the IHP uterine branches harvested during NSRH as an alternative to the IHP vesical branches between the waterjet and control groups. This study included samples from 30 eligible patients in each group of the trial NCT03020238. At least one specimen from each side of the IHP uterine branches was resected. The tissues were scanned, images were captured, and the neural component areas were calculated using the image segmentation method. Immunohistochemical staining was used to evaluate neural impairment. The control and waterjet groups had similar areas of whole tissues sent for evaluation. However, the control group had significantly fewer areas (median 272158 versus 200439 μm², p = 0.044) and a lower percentage (median 4.9% versus 3.0%, p = 0.011) of neural tissues. No significant changes in immunohistochemical staining were found between the two groups. For patients with residual urine ≤100 and >100 ml at 14 days after NSRH (42 and 18 patients, respectively), there were significantly different percentages of neural tissues in the resected samples (p < 0.001). Hence, Due to the accurate identification of IHP during NSRH, the waterjet dissection technique achieved better urodynamic results.

Computer-assisted surgery: virtual- and augmented-reality displays for navigation during urological interventions

PURPOSE OF REVIEW

To provide an overview of the developments made for virtual- and augmented-reality navigation procedures in urological interventions/surgery.

RECENT FINDINGS

Navigation efforts have demonstrated potential in the field of urology by supporting guidance for various disorders. The navigation approaches differ between the individual indications, but seem interchangeable to a certain extent. An increasing number of pre- and intra-operative imaging modalities has been used to create detailed surgical roadmaps, namely: (cone-beam) computed tomography, MRI, ultrasound, and single-photon emission computed tomography. Registration of these surgical roadmaps with the real-life surgical view has occurred in different forms (e.g. electromagnetic, mechanical, vision, or near-infrared optical-based), whereby the combination of approaches was suggested to provide superior outcome. Soft-tissue deformations demand the use of confirmatory interventional (imaging) modalities. This has resulted in the introduction of new intraoperative modalities such as drop-in US, transurethral US, (drop-in) gamma probes and fluorescence cameras. These noninvasive modalities provide an alternative to invasive technologies that expose the patients to X-ray doses. Whereas some reports have indicated navigation setups provide equal or better results than conventional approaches, most trials have been performed in relatively small patient groups and clear follow-up data are missing.

SUMMARY

The reported computer-assisted surgery research concepts provide a glimpse in to the future application of navigation technologies in the field of urology.

Clinical Outcomes in Early Cervical Cancer Patients Treated with Nerve Plane-sparing Laparoscopic Radical Hysterectomy

STUDY OBJECTIVE

To explore the feasibility of nerve plane-sparing laparoscopic radical hysterectomy (NPS-LRH) as a simplified C1-type surgery for cervical cancer patients and to compare this technique with laparoscopic radical hysterectomy (LRH).

DESIGN

A retrospective comparative study.

SETTING

An academic tertiary hospital affiliated with the Chinese National Cancer Center.

PATIENTS

Six hundred fifteen patients with Fédération Internationale de Gynécologie et d'Obstétrique stage Ib and IIa cervical cancer who underwent laparoscopic radical hysterectomy between January 2010 and December 2017 were enrolled. Among them, 263 patients underwent the NPS-LRH surgery, and 352 patients underwent the LRH surgery. Intraoperative data and postoperative outcomes were compared between the 2 groups.

INTERVENTIONS

NPS-LRH is a simplified type C1 procedure that preserves the ureteral mesentery and its nerve plane, whereas LRH is a type C2 procedure in the Querleu-Morrow surgical classification system.

MEASUREMENTS AND MAIN RESULTS

There were no statistically significant differences in age, body mass index, Fédération Internationale de Gynécologie et d'Obstétrique stage, tumor differentiation, pathological type, depth of invasion, lymphovascular space invasion, parametrial tissue invasion, lymphatic metastasis, neoadjuvant chemotherapy, or postoperative adjuvant radiotherapy and chemotherapy between the 2 groups. Compared with the LRH group, the NPS-LRH group had a shorter length of operation (238.7 ± 53.9 minutes vs 259.8 ± 56.6 minutes, p < .01), less intraoperative bleeding (p < .01), more resected lymph nodes (p = .028), shorter duration of urinary catheterization (p < .01), lower incidences of postoperative hydronephrosis (p = .044), less long-term frequent urination (p < .01), less acute urinary incontinence (p < .01), poor bladder sensation (p = .028), and constipation (p = .029). There were no statistically significant differences in the disease-free survival and overall survival between the 2 groups (p = .769 and .973, respectively).

CONCLUSION

NPS-LRH is a simplified, safe, and feasible type C1 operation that had a shorter length of operation, less intraoperative bleeding, more resected lymph nodes, and better postoperative bladder function compared with the LRH group. Further studies are required to assess its benefits on rectal function and long-term prognosis.

Cadaveric anatomy and dissection in surgical training

Detailed knowledge of anatomy is an essential part of surgical practice. However, there are many drawbacks in anatomy education that make many residents feel inadequate when they start performing surgeries. Cadaveric dissection courses aim to close the gap between the anatomic knowledge and surgical practice. This review focuses on the role of cadaveric dissection on surgical education, and additionally states the panel decision of the Surgical Anatomy and Technologies Association on the proper use of cadavers.

Neurovascular and lymphatic vessels distribution in uterine ligaments based on a 3D reconstruction of histological study: to determine the optimal plane for nerve-sparing radical hysterectomy

OBJECTIVE

To present the distribution of neurovascular and lymphatic vessels in uterine ligaments using 3D models based on the pathological staining of serial 2D sections of postoperative specimens.

METHODS

Serial transverse sections of fresh uterine ligaments from a patient with stage IB1 cervical squamous cell carcinoma were studied using the computer-assisted anatomic dissection (CAAD) technique. The sections were stained with hematoxylin and eosin, Weigert elastic fibers, D2-40 and immunostainings (sheep anti-tyrosine hydroxylase and rabbit anti-vasoactive intestinal peptide). The sections were then digitalized, registered and reconstructed three-dimensionally. Then, the 3D models were analyzed and measured.

RESULTS

The 3D models of the neurovascular and lymphatic vessels in uterine ligaments were created, depicting their precise location and distribution. The vessels were primarily located in the upper part of the ligaments model, while the pelvic autonomic nerves were primarily in the lower part; the lymphatic vessels were scattered in the uterine ligaments, without obvious regularity.

CONCLUSION

CAAD is an effective anatomical method to study the precise distribution of neurovascular and lymphatic vessels in uterine ligaments. It can present detailed anatomical information about female pelvic autonomic innervation and the spatial relationship between nerves and vessels and may provide a better understanding of nerve-sparing radical hysterectomy.

Local anatomy around terminal ureter related to the anterior leaf of the vesicouterine ligament in radical hysterectomy

OBJECTIVES

Radical hysterectomy is performed for invasive cervical cancer. In this surgery, separation of the anterior leaf and posterior leaves of the vesicouterine ligament (VUL) is important. We studied the local anatomy of the anterior leaf of the VUL, especially the branches of the umbilical artery from the view point of surgery and cadaver dissection.

STUDY DESIGN

We observed the cervicovesical blood vessels and the connective tissue layer continued from umbilical artery and searched for the origin of the cervicovesical blood vessels in radical hysterectomy. We also dissected a formalin-fixed female cadaver, and observed the same points.

RESULTS

After separation of the connective tissue of urinary bladder from the cervical fascia, we could discern the outline of the distal ureter near the ureterovesical junction. We separate the connective tissue of the so-called anterior leaf of the VUL enwrapping the ureter gently, and then the ureter with the connective tissue is completely rolled out laterally. We identified a cervicovesical vessel crossing over the ureter. We looked for the central side of the cervicovesical vessel and found that cervicovesical vessel was a branch of the superior vesical artery. And, during cadaver dissection, we found that the connective tissue and the branches of the superior vesical artery were similarly observed.

CONCLUSIONS

We found the precise anatomy of the connective tissue layer from umbilical artery to urinary bladder and the superior vesical artery. Our procedure based on the precise anatomy obtained in this study is reasonable anatomically as a method for separation of the vesicouterine ligament during radical hysterectomy.

The 3D reconstructions of female pelvic autonomic nerves and their related organs based on MRI: a first step towards neuronavigation during nerve-sparing radical hysterectomy

OBJECTIVES

To present in vivo female pelvic autonomous innervation and the relationship between nerves and their related organs by three-dimensional (3D) reconstruction based on magnetic resonance imaging (MRI).

METHODS

Thirty patients with cervical cancer who underwent pelvic MRI and agreed to undergo additional magnetic resonance neurography (MRN) sequences were enrolled in the present study. MRI images from the same patient were acquired using T2-weighted fat saturation (T2W FS) and 3D-STIR-SPACE sequences. Detailed two-dimensional (2D) segmentation and 3D reconstruction of pelvic autonomic nerves (PAN) were performed on the basis of the images of the two sequences using 3D reconstruction software. The 2D segmentation and 3D reconstruction of pelvic organs were based on T2W FS images. The consistency of the 3D models of pelvic autonomous innervation constructed from the two sequences were analysed and compared, the pelvic autonomous innervation was presented, and the relationship between nerves and their related organs was characterised.

RESULTS

The 3D reconstructions of PAN were successfully obtained from 3D-STIR-SPACE and T2W FS sequences in 30 patients and showed high correspondence. T2W FS images also enabled 3D reconstructions of pelvic organs to visualise the 3D distribution of PAN and the positional relationships between nerves and their related organs.

CONCLUSION

The pelvic autonomic nerves and their related organs can be reconstructed on the basis of MRI to present personalised 3D anatomical information and offer individualised guidance during nerve-sparing radical hysterectomy (NSRH).

KEY POINTS

• Nerve-sparing radical hysterectomy is a developing trend in cervical cancer surgery • MRI allows reconstructions of pelvic autonomic nerves and their related organs • The 3D reconstructions provide detailed 3D anatomical information on nerves.

A step towards stereotactic navigation during pelvic surgery: 3D nerve topography

Background

Long-term morbidity after multimodal treatment for rectal cancer is suggested to be mainly made up by nerve-injury-related dysfunctions. Stereotactic navigation for rectal surgery was shown to be feasible and will be facilitated by highlighting structures at risk of iatrogenic damage. The aim of this study was to investigate the ability to make a 3D map of the pelvic nerves with magnetic resonance imaging (MRI).

Methods

A systematic review was performed to identify a main positional reference for each pelvic nerve and plexus. The nerves were manually delineated in 20 volunteers who were scanned with a 3-T MRI. The nerve identifiability rate and the likelihood of nerve identification correctness were determined.

Results

The analysis included 61 studies on pelvic nerve anatomy. A main positional reference was defined for each nerve. On MRI, the sacral nerves, the lumbosacral plexus, and the obturator nerve could be identified bilaterally in all volunteers. The sympathetic trunk could be identified in 19 of 20 volunteers bilaterally (95%). The superior hypogastric plexus, the hypogastric nerve, and the inferior hypogastric plexus could be identified bilaterally in 14 (70%), 16 (80%), and 14 (70%) of the 20 volunteers, respectively. The pudendal nerve could be identified in 17 (85%) volunteers on the right side and in 13 (65%) volunteers on the left side. The levator ani nerve could be identified in only a few volunteers. Except for the levator ani nerve, the radiologist and the anatomist agreed that the delineated nerve depicted the correct nerve in 100% of the cases.

Conclusion

Pelvic nerves at risk of injury are usually visible on high-resolution MRI with dedicated scanning protocols. A specific knowledge of their course and its application in stereotactic navigation is suggested to improve quality of life by decreasing the likelihood of nerve injury.

Electronic supplementary material

The online version of this article (10.1007/s00464-018-6086-3) contains supplementary material, which is available to authorized users.

Limited energy parametrial resection/dissection during modified laparoscopic nerve-sparing radical hysterectomy

Objective

The aim of this study was to investigate the feasibility of using ultrasonic scalpel combined with vascular clip in parametrial management, called limited energy parametrial resection/dissection (LEPRD), in laparoscopic nerve plane-sparing radical hysterectomy (NPSRH), a modified nerve-sparing radical hysterectomy (NSRH); and to evaluate its effectiveness in pelvic autonomic nerve preservation.

Methods

From July 2012 to January 2016, 257 consecutive patients with stage IB1 to IIA2 cervical cancer who underwent NPSRH were included in this study. Patients were divided into three cohorts according to the different parametrial resection modality. The clinical, pathological and surgery-related parameters were compared between the three groups. Short- and long-term postoperative bladder functions were evaluated.

Results

LEPRD was attempted in 94 patients, and was successful in 65 (69.1%) patients (LEPRD group). The remaining 29 (30.9%) patients required bipolar coagulation after failure of vascular clipping (combined modality group). Routine bipolar cautery was used in the other 163 patients during the parametrial resection (bipolar group). The blood loss in the LEPRD group was significantly lower than those in the other two groups (P<0.001). The rate of successful Foley removal on postoperative day 7 was significantly higher in the LEPRD group than in the bipolar group (P=0.022). The incidence of chronic voiding dysfunction was significantly lower in the LEPRD group than in the bipolar group (P=0.019).

Conclusions

It is feasible to perform LEPRD in NPSRH for cervical cancers. This kind of limited energy surgical technique is associated with less blood loss, and leads to improved postoperative bladder function.