Peter A Davis
David J Corless
Sigmoidoscopy forms part of the routine examination of patients who complain of colorectal symptoms. Patients presenting with rectal bleeding or a change in bowel habit should undergo either a rigid Sigmoidoscopy followed by a barium enema, or a colonoscopy. In addition, patients presenting with vulval carcinoma extending to the perineum should have anal and rectal assessment. Flexible Sigmoidoscopy can be used to confirm lesions in the distal colon and rectum, to obtain material, and in the follow-up of patients who have undergone colonic resections.
Rigid Sigmoidoscopy can be performed in the outpatient department without any special preparation. Bowel preparation in most instances is unnecessary but in some cases faeces in the rectum may limit views and the advancement of the sigmoidoscope. In these cases either a glycerine suppository or a phosphate enema can be used prior to the examination.
Flexible Sigmoidoscopy is usually carried out in the endoscopy suite with or without sedation. Adequate bowel preparation of the left colon and rectum is usually provided by a regimen of clear fluids for 24 hours and two sachets of sodium picosulphate taken the previous day.
The rigid sigmoidoscope (Figure 1) is approximately 25 cm long with a 19 mm internal diameter and an internal obturator to aid insertion. It has a detachable eye-piece, which allows instruments to be passed along the shaft, and a circumferential light source. Bellows attached to the distal end are used to insufflate the rectum with air. Newer instruments are disposable, being made of self-lubricating plastic. Useful appendages are a punch biopsy, grasping forceps and suction tubing.
Rigid sigmoidoscope and proctoscope
Flexible sigmoidoscope or colonoscope
The flexible sigmoidoscope (Figure 2) is 70-110 cm long and consists of a control head with eye-piece and controls, a multichannel flexible shaft and a control-lable tip. The flexible shaft contains fibreoptic channels carrying the optics and light source to the visual field, as well as channels for suction, irrigation and insufflation of the colon, and the passage of instruments. Movement of the tip in two planes is produced by pulling wires operated at the control head. The eye-piece can be attached to a video camera and the image viewed on a monitor. Immediately after use, instruments should be washed in fresh disinfectant in accordance with the manufacturers' instructions.
View of rectum at sigmoidoscopy
Patients are usually placed in the left lateral position on a couch or bed and a digital examination of the rectum is performed. The sigmoidoscope is held in the right hand with the left hand holding the buttocks for insertion. The instrument is lubricated and inserted into the anal canal, pointing towards the umbilicus with the obturator in place. When the instrument is felt to enter the rectum it is directed posteriorly and the obturator removed. Using the bellows the rectum is gently insufflated with air which allows the sigmoidoscope to be advanced while visualizing the whole circumference of the lumen. As the sigmoidoscope is passed through the rectum it follows an anterior curve formed by the hollow of the sacrum (Figure 3). Inspection of the whole mucosa can be achieved by rotating the instrument. Negotiation of the instrument at the rectosigmoid junction should be carried out with care; it can be achieved using gentle insufflation and manipulation in order to find the lumen of the sigmoid colon. The best views are often obtained while withdrawing the sigmoidoscope, and inspection of the mucosa—particularly around the horizontal rectal folds—should be carried out.
The sigmoidoscope is manipulated so that the lesion is at the tip of the instrument. The glass eye-piece is removed; although this causes deflation of the rectum, the lesion should still be in view. Punch biopsy forceps are passed along the sigmoidoscope and the biopsy is taken under direct vision. The jaws of the biopsy forceps are closed around the lesion and removal is aided by rotation of the closed forceps. Excessive bleeding at the site of the biopsy can easily be controlled with pressure from a cotton-wool swab or occasionally injection of 1 in 1000 adrenaline.
Polyps with a long stalk can be removed using a diathermy snare technique through the rigid sigmoidoscope. The polyp is grasped with polyp-holding forceps which have been passed through the loop of a diathermy snare. The snare is then passed over the polyp and closure of the snare during application of diathermy coagulates the stalk. The polyp is then removed by the forceps and the excision site inspected for bleeding. It is important to avoid excessive traction on the forceps since this may result in removal of excess normal mucosa and hence perforation.
Patients are placed in the left lateral position on a couch or bed and a digital examination of the rectum is performed. Intravenous sedation and oxygen may be administered via a face mask or nasal prongs and a pulse oximeter attached to the patient. The tip of the sigmoidoscope is lubricated and inserted into the anal canal for a distance of 4-5 cm. Initially inspection usually reveals a red blur as the tip of the sigmoidoscope rests against the rectal mucosa. The rectum is gently inflated and the tip position adjusted and withdrawn until the lumen comes into view. It may be necessary to adjust the focus, wash the lens and suck out any residual fluid or faeces to optimize the image. With gentle insufflation and guidance of the tip, the sigmoidoscope is advanced through the lumen and the rectosigmoid junction negotiated under direct vision. If the lumen or movement across the mucosa is not seen, then the sigmoidoscope should be withdrawn until the lumen once again comes into view. Looping of the sigmoidoscope prevents advancement and in such cases the instrument should also be withdrawn. In most patients, a combination of manipulation of the tip and twisting of the shaft should make it possible to examine the whole left colon. The best views are once again seen on slow withdrawal of the sigmoidoscope, keeping the lumen in view all the way and aspirating as much air as possible. Biopsy can also be performed on withdrawal. The lesion is cleaned by injecting water down the irrigation channel and biopsy forceps are passed through the instrument port. The biopsy is taken under direct vision, the closure usually performed by an assistant who then removes the forceps while the operator directs the sigmoidoscope and the position of the biopsy. The incidence of perforation with flexible sigmoidoscopy is extremely low, but if the patient complains of excessive pain or discomfort then the examination should cease.
No special postoperative care is necessary after routine sigmoidoscopy. After a polypectomy or biopsy the patient should be observed for signs of excessive bleeding or perforation. Barium enema should not be performed for 10 days after biopsy because of the risk of extravasation of contrast.
Cystoscopy is the single most common urological procedure and is used in the investigation of urinary symptoms. Patients who present with urological symptoms such as frequency, dysuria and haematuria undergo cystoscopy for the diagnosis of lesions of the urethra and bladder. In addition, cystoscopy may be performed as part of the FIGO preoperative staging for cervical carcinoma or where it is suspected that
Rigid cystoscope tumours may involve the bladder and urethra. It can also be used to perform retrograde ureterography to provide x-ray visualization of the ureter and collecting system and the placement of retrograde ureteric stents. Stents provide ureteric drainage and can also be used to identify the position of the ureter. Where retrograde stenting proves impossible the interventional radiologist may well be able to pass antegrade stents or, failing this, to insert bilateral nephrostomy tubes.
Rigid cystoscopy is carried out under general anaesthesia in the operating theatre with the patient in the lithotomy position. It is important to rule out severe osteoarthritis of the hips which may make examination impossible. Antibiotic prophylaxis is given if there is any evidence or suspicion of a urinary tract infection.
Flexible cystoscopy is usually carried out in the endoscopy suite under local anaesthesia. Lignocaine (lidocaine) gel inserted into the urethra acts as both lubricant and local anaesthetic agent. If possible the patient should void prior to examination to ensure the bladder is empty.
The rigid cystoscope (Figure 4) is composed of a sheath, a bridge and a telescope: it is 30 cm long. The sheath has both an inlet and an outlet port for irrigation and is attached to the bridge with a watertight lock. The endoscope is introduced into the sheath through the bridge, and is also fitted with a watertight lock. The telescope comprises a hollow metal cylinder containing a series of solid rod lenses and a magnifying eyepiece. In front of the eye-piece is a pillar connected to a fibre-optic light source which transmits light to the visual field. The bridge has one or two other ports for the introduction of biopsy forceps and electrodes, and a director which allows the passage of a ureteric catheter and its advancement into the ureteric orifice. Endoscopes with viewing angles of 0°, 30°, 70° and 90° are available.
The flexible cystoscope (Figure 5) is 35-40 cm long and consists of a control head with eye-piece and controls, a multichannel flexible shaft and a controllable tip. The flexible shaft contains fibreoptic channels carrying the optics and light source to the visual field, an irrigation channel and a biopsy channel. Movement of the tip occurs in one plane and ranges from 145° to 180°, controlled by a deflecting level adjacent to the eye-piece.
The patient is placed on the operating table in the lithotomy position. The cystoscope sheath is lubricated and introduced into the urethra. The female urethra is about 4 cm long and has a relatively uniform calibre from the meatus to the bladder outlet. Upon entering the bladder the telescope is removed to allow the residual urine and irrigant to drain from the bladder: this may be sent for cytological and bacteriological analysis. Approximately 50 ml of saline is inserted and the fundus of the bladder is identified by finding the air bubble. With incomplete distension the bladder mucosa appears rugated, but as the irrigant fluid distends the bladder the mucosa becomes smooth. The ureteric orifices are visualized on the interureteric ridge at the superolateral corners of the trigone (Figure 6). By regular sweeping of the cystoscope backwards and forwards and rotation of the endoscope the entire bladder mucosa can be visualized. Views of the
Bladder biopsy anteroinferior bladder are obtained by suprapubic compression with the hand. At the completion of the examination, the irrigating fluid is evacuated from the bladder by removing the telescope and the instrument is slowly withdrawn. A bimanual examination of the pelvis is performed after the procedure.
Bladder biopsy (Figures 7, 8) is the procedure most commonly performed during cystoscopy Biopsy forceps are introduced down the cystoscope sheath via a port in the bridge, sometimes together with a diathermy wire. This allows cup biopsies of the mucosa to be taken. If required, the biopsy sites are then cauterized with diathermy to prevent excessive bleeding.
The instrumentation and stenting of ureters should only be performed by clinicians such as gynaecologic oncologists trained in this procedure since it is easy to damage the ureteric orifices and ureters. Ureteric catheterization and the placement of double J stents is achieved with the 30° telescope. There is a special port for the introduction of the stents which can be directed towards the ureteric orifices. A floppy-tipped, Teflon-coated guide wire is first placed into the ureteric orifice and advanced under fluoroscopic control into the renal pelvis. The double J stent is slid over the guide wire through the channel of the cystoscope and into the ureter (Figure 9). The stent is radio-opaque and its position is monitored by fluoroscopic control. Excessive force used in insertion of the guide wire or stent should be avoided. The proximal and distal ends curl to form a J shape when they are correctly placed in the renal pelvis and bladder respectively.
The patient is placed on the operating table or bed in the 'frog-leg' position. The cystoscope is lubricated and introduced into the urethra. The end of the cystoscope is passed into the bladder and deflected upwards.
The midline of the anterior bladder is examined by withdrawing the instrument until the bladder outlet is encountered. The cystoscope is then pushed back into the bladder, rotated 30° and withdrawn again. This process is continued until the entire bladder has been inspected. Biopsy of the bladder mucosa can also be achieved by the passage of biopsy forceps down the instrumental channel of the cystoscope.
No special postoperative measures are needed.
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