The pudendal nerve (S2–S4) exits the pelvis initially through the greater sciatic foramen below the piriformis. Importantly, it runs behind the lateral third of the sacrospinous ligament and ischial spine alongside the internal pudendal artery and immediately re-enters the pelvis through the lesser sciatic foramen to the pudendal canal (Alcock’s canal). This nerve is susceptible to entrapment injuries during sacrospinous ligament fixation as it runs behind the lateral aspect of the sacrospinous ligament.

The anterior branches of L2–L4 give rise to the obturator nerve and converge behind the psoas muscle. The obturator nerve then passes over the pelvic brim in front of the sacroiliac joint and behind the common iliac vessels to enter the thigh via the obturator foramen. This nerve is most frequently injured during retroperitoneal surgery, excision of endometriosis, the passage of a trocar through the obturator foramen, insertion of transobturator tapes and during paravaginal defect repairs.

The sciatic nerve arises from the L4–S3 nerve roots. It emerges from the pelvis below the piriformis muscle, curving laterally and downward through the gluteal region. Initially it lies midway between the posterior superior iliac spine and ischial tuberosity. Lower down in the thigh, it courses midway between the ischial tuberosity and greater trochanter.

The common peroneal nerve and tibial nerve are its two derivatives at the mid-thigh. The common peroneal nerve importantly winds forward around the neck of the fibula.

The genitofemoral nerve originates from the upper L1–2 segments. It passes downwards and emerges from the anterior surface of the psoas muscle.

Kuponiyi O, Alleemudder DI, Latunde-Dada A, Eedarapalli P. Nerve injuries associated with gynaecological surgery. Obstet & Gynaecol. 2014; 16:29–36.

Morrion J, MacKenzie I. Avoiding and managing complications during gynaecological surgery. Obstet, Gynaecol Reprod Med. 17(4):105–11.

Painful bladder syndrome (PBS) is categorised by suprapubic pain related to bladder filling, accompanied by other symptoms such as increased daytime and night-time frequency in the absence of proven urinary tract infection or other pathology. There is considerable overlap between the overactive bladder syndrome, the urethral pain syndrome and PBS. Whereas the principal complaint of women with OAB is urgency, in women with PBS, it is predominantly pain related to bladder filling. Women with urethral pain syndrome, on the other hand, complain of pain on voiding.

Jha S, Parsons M, Toozs-Hobson P. Painful bladder syndrome and interstitial cystitis. Obstet Gynaecol. 2007;9:34–41.

The ureters are muscular tubes whose peristaltic contractions convey urine from the kidneys to the urinary bladder. Each descends slightly medially anterior to psoas major and enters the pelvic cavity where it curves laterally and then medially, as it runs down to open into the base of the urinary bladder. In the female pelvis, it forms an important relation to the ovarian fossa and comes to lie posterior to the ovaries. It is closely related to the uterine artery lateral to the uterine cervix and runs under it—best remembered as ‘water under the bridge’.

Ureteric tunnel is the Mackenrodt’s or the cardinal ligaments through which the ureter passes before entering the bladder. ‘Unroofing of the ureter’ and freeing it from the ligaments is necessary to excise a portion of the parametria during radical hysterectomy for cervical cancer. It ends by piercing the posterior aspect of the bladder after emerging from the ureteric tunnel.

Gray’s anatomy – Chapter – Kidneys and ureter.

Postpartum voiding dysfunction is failure to pass urine within 6 h of vaginal delivery. Epidural anaesthesia decreases sensation as hence is a recognised risk factor. Other risk factors are primigravida, instrumental delivery, prolonged labour and perineal trauma. Postpartum measuring residual urine volume in asymptomatic women is not helpful.

Post partum voiding dysfunction. TOG. 2008;10:71–4.

Obliterating the uterosacrals by continuous sutures and the peritoneum of the posterior cul de sac as high as possible (high uterosacral suspension) helps to prevent vault prolapse during vaginal hysterectomy. Moschowitz-type operation involves a purse-string technique, incorporating the distal ends of the uterosacral and cardinal ligaments and thereby drawing these structures to the midline. Simple closure of the peritoneum is done with a purse-string suture, with none of the uterosacral-cardinal ligaments incorporated into the repair. Cruikshank and Kovac performed the only prospective, randomised comparison of procedures used at the time of hysterectomy to prevent enterocele. In their study, 100 patients undergoing vaginal hysterectomy for various indications (excluding prolapse of the posterior superior segment of the vagina) were randomised to 1 of 3 surgical methods to prevent enterocele. The McCall repair was significantly more effective than the other 2 types of repair, with a 6.1 % risk of subsequent prolapse, versus 30.3 % in women who had a Moschcowitz-type closure and 39.4 % in those who underwent simple closure of the peritoneum.