Auditory nerve preservation and regeneration in man:relevance for cochlear implantation

Human hearing relies on 15,000 hair cells （HCs） or mecha- noreceptors sited in a 34 mm long helical shaped epithelial ridge. There may be several explanations for their vulner- ability in man and regrettably, they do not regenerate. Ap- proximately 35,000 bipolar neurons have their soma situated in the modiolus of the cochlea. Human afferents consist of two separate systems; one is represented by the large type I cells innervating the inner HCs （IHCs, n = 3,400） and the other one by the small type Ⅱcells innervating the outer HCs （OHCs, n = 12,000）. Type I spiral ganglion neurons （SGNs） constitute 96% of the afferent nerve population. Unlike in other mammals, their somas together with the pre- and post-somatic segments are unmyelinated. Type II nerve cell soma and fibers are unmyelinated.

Facial nerve preservation following microsurgical removal of large and huge acoustic neuroma

Objective To evaluate the long-term facial nerve funtion of patients following microsurgical removal of large and huge acoustic neuroma,and to indentify the factors that influence these outcomes. Methods A retrospective review was performed,which included 176 consecutive patients with a

Pelvic autonomic nerve preservation in radical rectal cancer surgery:changes in the past 3 decades

The advent of total mesorectal excision(TME)together with minimally invasive techniques such as laparoscopic colorectal surgery and robotic surgery has improved surgical results.However,the incidence of bladder and sexual dysfunction remains high.This may be particularly distressing for the patient and troublesome to manage for the surgeon when it does occur.The increased use of neoadjuvant and adjuvant radiotherapy is also associated with poorer functional outcomes.In this review,we evaluate current understanding of the anatomy of pelvic nerves which are divided into the areas of the inferior mesenteric artery pedicle,the lateral pelvic wall and dissection around the urogenital organs.Surgical techniques in these areas are discussed.We also discuss the results in functional outcomes of the various techniques including open,laparoscopic and robotic over the last 30 years.

Effects of Laparoscopic Pelvic Autonomic Nerve-Preserving Radical Resection of Rectal Cancer on Urinary and Sexual Function

Objective:To investigate and analyze the effect of laparoscopic pelvic autonomic nerve-preserving radical resection of rectal cancer on urinary and sexual function.Methods:Cases of laparoscopic radical resection of rectal cancer in our hospital from April 2018 to April 2023 were selected,and 60 patients who met the requirements were included as research subjects.The patients were divided into an experimental group and a reference group by a double-blind mechanism,with 30 cases in each group.The experimental group underwent laparoscopic pelvic autonomic radical resection,while the reference group underwent ordinary radical resection.The voiding function,urodynamics,sexual function,and blood indexes of the patients of both groups were compared.Results:The total incidence of voiding dysfunction in the experimental group was significantly lower than in the reference group(P<0.05).Urodynamics such as abdominal leak point pressure(ALPP),maximum urethral pressure(MUP),maximum urethral closure pressure(MUCP),and functional urethral length(FUL)in the experimental group were significantly better than those in the reference group(P<0.05).The incidences of erectile dysfunction and ejaculatory dysfunction in the experimental group were significantly lower than those in the reference group(P<0.05).Before the surgery,there were no significant differences in the blood indexes such as C-reactive protein(CRP),cortisol(Cor),and pre-albumin(PA)between the two groups(P>0.05);after the operation,the blood indexes of the patients in the experimental group were significantly better than those in the reference group(P<0.05).Conclusion:Laparoscopic pelvic autonomic nerve-preserving radical resection of rectal cancer has lesser effects on urinary and sexual functions.

The optimal timing of post-prostate biopsy magnetic resonance imaging to guide nerve-sparing surgery

The goal of our study was to evaluate the impact of the interval between prostate biopsy and magnetic resonance imaging （MRI） on the accuracy of simple tumor localization, which is essential information that enables nerve-sparing surgery. We also sought to determine the optimal timing of a post-biopsy MRI, A total of 184 patients who had undergone MRI before radical prostatectomy at an institution without a predetermined schedule for MRI after a prostate biopsy were enrolled. The mean interval from the biopsy to the MRI was 30.8 ± 18.6days. The accuracy of the MRI for simplified tumor location （right, left, bilateral and none） was 44.6%. In the group with discordant pathologic and MRI findings, the most common reason recorded was ＇MRI predicted a unilateral lesion, but pathology revealed bilateral lesions＇ （58.3%）, followed by ＇MRI predicted no lesion, but pathology revealed the presence of a lesion＇ （32.0%）. Multivariable analysis showed that the discordant group had a shorter interval （25.0 ± 14.3 vs 38.1 ± 20.6days, P 〈 0.01） preceding the MRI and a higher rate of hemorrhage as observed by MRI （80.4% vs 54.8%, P 〈 0.01） in comparison with the accordant group. In receiver operating characteristics analysis, the area under the curve of the MRI interval in accurate prediction of the tumor location was 0.707 （P 〈 0.001）. At the MRI interval＇s cutoff of 28.5days, the sensitivity was 73.2% and the specificity was 63.7%. When the MRI was performed within 28days, the accumulated accuracy was only 26.1% （23/88）; however, when it was performed after 28days, the reversely accumulated accuracy was 61.5% （59/96）. These data support a waiting period of at least 4weeks after a biopsy before performing an MRI for the purposes of surgical refinement.

A study evaluating the impact of nerve preserving surgery and adjuvant pelvic irradiation for rectal cancer on quality of life

Objective： Preservation of the pelvic autonomic nerves in order to lower bladder and sexual dysfunction after radical rectal cancer surgery ＆ to evaluate functional outcome, local recurrence. Methods： A prospective study was under- taken on Egyptian patients. Forty one patients participated in the study in the period from December 2002 till June 2004 where they underwent radical surgery but with preservation of the pelvic autonomic nerves this was followed by adjuvant pelvic radiotherapy. Results： Six months, 1-year and 2-year follow-up of urinary function was complete in 32 out of 41 （78%）, 30 out of 41 （73%） and 27 out of 41 patients （65%） respectively There was no statistically significant correlation between the extent of nerve preservation and the reported minor voiding dysfunction. None of the patients reported major incontinence. Six months, 1-year and 2-year follow-up of sexual function revealed that 22 out of 41 patients （53%） were sexually active. Three out of 41 patients （7.3%） developed local recurrence. 38 （92.7%） patients were free of local recurrence, regarding pa- tients who received adjuvant radiotherapy 3 out of the 34 （8.8%） patients developed local pelvic recurrence while 9 patients （26.5%） developed distant metastases （3 of them did not receive adjuvant chemotherapy）, while patients who received adju- vant chemotherapy, 2 out of 20 patients （10%） developed local recurrence while distant metastases developed in 6 patients （30%）. Conclusion： Preservation of the pelvic autonomic nerves minimizes bladder and sexual dysfunction especially in male patients after rectal cancer surgery.

Identification of the surgical indication line for the Denonvilliers’fascia and its anatomy in patients with rectal cancer

Background:The high rate of urogenital dysfunction after traditional total mesorectal excision(TME)has caused doubts among scholars on the standard fashion of dissection.We have proposed the necessity to preserve the Denonvilliers’fascia in patients with rectal cancer.However,how to accurately locate the Denonvilliers’fascia is unclear.This study aimed to explore anatomical features of the Denonvilliers’fascia by comparing autopsy findings and observations of surgical videos so as to propose a dissection method for the preservation of pelvic autonomic nerves during rectal cancer surgery.Methods:Five adult male cadaver specimens were dissected,and surgical videos of 135 patients who underwent TME for mid-low rectal cancer between January 2009 and February 2019 were reviewed to identify and compare the structure of the Denonvilliers’fascia.Results:The monolayer structure of the Denonvilliers’fascia was observed in 5 male cadaver specimens,and it was located between the rectum,the bottom of the bladder,the seminal vesicles,the vas deferens,and the prostate.The Denonvilliers’fascia was originated from the rectovesical pouch(or rectum-uterus pouch),down to fuse caudally with the rectourethral muscle at the apex of the prostate,and fused to the lateral ligaments on both sides.The fascia was thinner on the midline with a thickness of 1.06±0.10 mm.The crown shape of the Denonvilliers’fascia was slightly triangular,with a height of approximately 5.42±0.16 cm at midline.Nerves were more densely distributed in front of the Denonvilliers’fascia than behind,especially on both sides of it.Under laparoscopic view,the Denonvilliers’fascia was originated at the lowest point of the rectovesical pouch(or rectum-uterus pouch),with a thickened white line which was a good mark for identifying the Denonvilliers’fascia.Conclusion:Identification of the surgical indication line for the Denonvilliers’fascia could help us identify the Denonvilliers’fascia,and it would improve our ability to protect the pelvic autonomic function of patients undergoing TME for rectal cancer.