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Urological complications following gynaecological surgery
REVIEW
Urological complications following gynaecological surgery
injury is elevated by the presence of congenital anomalies e.g. horse shoe kidney, or acquired distortions of the pelvic anatomy by adhesions, endometriosis, malignancy, large pelvic masses or previous radiotherapy. Emergency surgery such as caesarean hysterectomy or laparotomy for ectopic pregnancy may involve the need to obtain rapid haemostasis, so the risk of urinary tract damage increases. A bloody operative field may lead to poor visualization of pelvic anatomy and therefore blind clamping of pedicles and placement of sutures. This situation can be compounded by surgical factors such as insufficient anatomical knowledge of the path of the ureter, an inexperienced surgeon or poor surgical techniques. Advances in minimal access surgery have led to an increase in the number of gynaecological procedures being performed by laparoscopy. This requires a high degree of technical ability and dexterity, and so has a significant learning curve. Diathermy is the leading cause of ureteric injury at laparoscopy and the ureter is most vulnerable when the vaginal cuff is taken.
Anna Haestier Robert Sherwin
Abstract Iatrogenic injury of the lower urinary tract occurs during benign gynaecological surgery with a frequency of approximately 0.3%. The injuries sustained are often not detected intra-operatively, but on many occasions, the vulnerability of the urinary tract to injury can be anticipated by rigorous pre-operative assessment and the risk of injury reduced by intra-operative vigilance. Primary prevention offers the best outcome for patients, reducing acute and long-term morbidity, and reducing the risk of litigation. A high index of suspicion must be maintained for patients who present with atypical symptoms such as loin pain or per vaginal clear fluid loss following gynaecological surgery and early recourse to imaging and urological review should be sought. The risk of litigation following iatrogenic urinary tract damage can be reduced by appropriate behaviour of clinicians. Iatrogenic urinary tract infection or bladder over-distension injuries can also be reduced by following evidence based guidelines for cystoscopy and catheterization.
Aetiology of iatrogenic urinary tract damage Estimates of the frequency of ureteric injuries during gynaecological surgery range from 0.002 to 2.5%. The ureter is the most vulnerable part of the lower urinary tract and there are case reports of ureteric damage following most operative gynaecological procedures. Studies suggest that gynaecological surgery accounts for about 75% of all iatrogenic ureteric injuries. The sites of injury are most commonly at the pelvic brim, near to the infundibulo-pelvic ligament and at the pelvic sidewall, where the ureter passes beneath the uterine artery. The majority of injuries occur to the distal ureter (51%), with the upper third damaged in approximately 30% and the middle third in 19% of cases. The ureter may be damaged in several ways including, crushing by a clamp, tethering by a ligature, partial or complete transection, devascularization or indirectly through energy sources, e.g. diathermy, laser or microwave. Bilateral injuries are rare but account for 5% of all ureteric injuries and if they remain unrecognized can be fatal. Bladder injuries occur with frequency of 1e5%, most commonly during reflection of the utero-vesicle peritoneal fold as part of caudal dissection of the bladder. The bladder is as vulnerable as the ureter to indirect damage by energy sources. Previous caesarean section significantly increases the risk of unintentional cystotomy at pelvic surgery, especially during abdominal hysterectomy. The majority of litigation related to bladder injuries follows fistula formation, which is a consequence of suture placement through the bladder during the closure of the vaginal cuff at hysterectomy. Urethral injuries are very rare and their true incidence is unknown. In females the urethra is only 4 cm long, but it is susceptible to damage along its’ entire length during pelvic floor surgery. The most frequent complication is a urethral tear, sustained during catheterization, cystoscopy or urethral diverticulumectomy, which may be complicated by fistula formation.
Keywords bladder perforation; functional bladder disorder; good practice; iatrogenic injury; litigation; over-distension injury; ureteric injury; urinary tract infection
Introduction All gynaecological operations have the potential to injure the lower urinary tract, due to the anatomical proximity of the reproductive tract to the ureters, bladder and urethra. Since the first description of hysterectomy, urinary tract injuries have been reported and this potentially devastating complication continues to plague gynaecological surgeons. Urinary tract trauma is associated with longterm morbidities such as vesico-vaginal fistula, ureteric stenosis, hydronephrosis and renal failure. Although extremely rare, death may result from undetected injuries.
Risk factors for iatrogenic urinary tract trauma Most iatrogenic damage to the urinary tract occurs in patients with conditions that alter the normal pelvic anatomy: The risk of
Anna Haestier BSc (Hons) MBBS PgD MRCOG is a Specialty Trainee 6 in Obstetrics and Gynaecology at Hinchingbrooke Hospital, Huntingdon, Cambridge, UK. Conflicts of interest: none declared.
Preventing iatrogenic injury
Robert Sherwin MA PhD MRCOG is a Consultant Obstetrician and Gynaecologist at the Whittington Hospital, London, UK. Conflicts of interest: none declared.
OBSTETRICS, GYNAECOLOGY AND REPRODUCTIVE MEDICINE 21:1
Damage prevention begins with careful pre-operative patient selection. Conservative and medical treatment options should be given careful consideration in women who may have altered
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Ó 2010 Elsevier Ltd. All rights reserved.
REVIEW
pelvic anatomy (see above). If pelvic distortion is anticipated preoperative imaging by contrast CT or ultrasound should be used to identify the course of the ureter, to establish any pre-existing renal collection system dilatation and identify pre-existing renal parenchymal damage. These modalities have no role in preventing damage during routine cases. Pre-operative ureteric catheterization or stenting should be considered when pelvic anatomy is distorted, but case reports have highlighted damage to the ureteric mucosa caused by intra-operative manipulation of the ureter with a stent in-situ. Economic evaluation of elective ureteric stenting has been evaluated and appears not to be cost effective in low risk cases therefore it does not have a role in preventing damage during routine elective cases. Intra-operatively many strategies have been used to reduce the risk of iatrogenic damage. Routine exposure of the ureter during abdominal hysterectomy, by retroperitoneal dissection before ligation of the uterine arteries, has been shown to reduce ureteric injury from 0.7% to 0.2%. Some surgeons attempt to palpate the ureter as well as looking for vermiculation, the “wormlike” movement of the ureter. However in obese patients or when the anatomy is distorted, this may not be possible. If there is any doubt about the course of the ureter or position of the bladder once the peritoneum has been opened, a urological opinion should be sought, before continuing with the procedure.
routine gynaecological operations, as bladder injuries may be missed and urethral instrumentation increases the risk of infection. Intra-operative cystoscopy should be only used for complex pelvic floor surgery, cases of malignancy and during operations that have been complicated by distorted anatomy. If urinary tract damage is suspected in the post-operative period, then investigations should include a full blood count and electrolyte profile. A full blood count may show an elevated white cell count with a neutrophilia. Hyponatraemia may be suggestive of free spill of urine into the peritoneal cavity as reabsorption of free water causes a decrease in serum osmolality and serum sodium. A rise in serum creatinine levels beyond the second post-operative day may be indicative of ureteric damage. However this is not specific for damage, as other factors can influence the elevation of this analyte, including inadequate fluid resuscitation and nephrotoxic drugs. Post-operative ureaemia is a sign of either dehydration or total urinary tract obstruction. Failure of this waste product to be cleared from serum following adequate rehydration warrants urgent investigation. Radiological imaging is vital for identification of the site of the urinary tract obstruction or leak (Figure 1). Computer tomography with intravenous contrast is commonly used to check the patency of the entire urinary tract. Radiological features of urinary tract damage include dye extravasation or absence of dye in the urinary tract. Ultrasound is a quick non-invasive test that has great sensitivity for detection of hydronephrosis, and retroperitoneal urinomas, but it cannot be used as the primary diagnostic modality for identification of the course and integrity of the ureter. Intravenous urography has been largely superceded by computed tomography, but still has a role for identification of hydronephrosis, ureteric and bladder patency. Post-operative cystoscopy may be used as an adjunct to radiological imaging. The triple swab test for suspected bladder fistula is a quick
Presentation of urinary tract injury Many injuries such as ureteric tethering or suture placement through the bladder may go unrecognized, as the patient can be asymptomatic. In symptomatic cases, presentations include immediate or delayed post-operative flank pain, fever, peritonitis, haematuria, anuria, ileus, secondary hypertension or urinary leakage through the vagina, abdominal wound or even rectum. Post-operative anuria is most likely caused by hypovolaemia, but it requires prompt investigation as this can be a sign of bilateral ureteric damage. If any of these signs go unnoticed or fail to be investigated then long-term sequelae including fistulas, renal failure or death may occur.
Diagnosis of urinary tract injury If damage occurs, intra-operative recognition and repair ultimately results in the best outcome for the patient, therefore constant checks for the integrity of the urinary tract should be made during gynaecological surgery. Several studies have reported that up to two thirds of cases of ureteric damage go undetected at time of operation. When ureteric damage is suspected, it can be confirmed by several methods. Intravenous administration of indigo carmine or methylene blue can be used to verify ureteric patency, with the passage of dye through both ureteric orifices confirmed by cystoscopy. If there has been no efflux of dye 15 min post injection, the diagnosis of ureteric damage should be suspected. Bubbles or blood exiting through the ureteric orifices may also indicate ureteric damage. Bladder damage is usually more obvious, with overt urinary leakage, visualization of the indwelling catheter or a breach of the bladder being detected during surgery. Many studies have evaluated the role of routine intra-operative cystoscopy for the early diagnosis of bladder damage. These studies have concluded that cystoscopy has limited value as a screening tool during
OBSTETRICS, GYNAECOLOGY AND REPRODUCTIVE MEDICINE 21:1
Figure 1 A 32-year-old woman who presented with vaginal urine leak on day 1 after caesarean section. This antegrade pyelogram shows extravasation of contrast from the distal ureter. A guidewire has been passed through the injured lower right ureter into bladder.
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Ó 2010 Elsevier Ltd. All rights reserved.
REVIEW
bedside test, which can be performed while waiting for imaging. Three gauze swabs are placed in the vagina and methylene blue dye is instilled transurethral into the bladder. The presence of dye on one of the uppermost swabs indicates the presence of a vesico-vaginal fistula (VVF). If the upper swabs are wet but not blue, this indicates a ureteric fistula.
Management of iatrogenic urinary tract damage The best outcomes occur where urinary tract damage is recognized early and repaired immediately. A surgeon with adequate training, experience and current clinical workload should perform the surgical repair. In most situations this will require the in put of a urologist. The management depends up on the location, mechanism and extent of the injury. For bladder lacerations, the defect should be closed in two layers with an absorbable suture. On completion of the repair the defect must be shown to be watertight by the intravesical administration of dye, e.g. methylene blue. An indwelling catheter should be left in-situ for at least 1 week to decompress the bladder to allow healing. The repair of ureteric damage is more complicated as the choice of surgical technique usually depends on the site of ureteric damage in relation to the bladder, the size of the defect and when the injury is detected. If the ureteric defect is short (<2.5 cm), detected soon after the initial procedure (<3 weeks) and a stent can be placed across the injury, then excellent short and long-term results can be obtained by stenting the ureter. If stenting is not appropriate or possible, then immediate open surgical repair (within 3 weeks) has similar or better results compared to an interval procedure performed at 6 weekse3 months post injury. Percutaneous nephrosotomy drainage should be considered until definitive surgery can be performed, to drain the kidney and reduce inflammation caused by extravasation of urine. If the injury occurs less than 5 cm from the vesico-ureteric junction then uretero-neocystostomy (ureteric reimplantation) should be performed. This procedure involves creating a submucosal tunnel within the bladder. A new urethral orifice is constructed in a watertight fashion and a stent left insitu for 6 weeks. Alternatively a Boari flap (Figure 2) or Psoas hitch can be performed where the defect is covered by a tubularized section of the bladder, so bridging the gap. If the injury is more than 5 cm from the vesico-ureteric junction, then an end-toend anastomosis can be performed with spatulation of the ureteric ends. Complete transection of the ureter with loss of length can be repaired by anastomosis to the contralateral ureter. If a ureter is tethered by a suture, then this should be removed promptly. Thermal injury may lead to tissue ischaemia and so may require excision and ureteric reanastomosis or re-implantation. In cases of complete transection, if the defect is close to the bladder then uretero-neocystotomy can be performed. Following repair a stent should be placed and the bladder drained to facilitate healing. Complications arising from surgery performed to repair damage include a ureteric stricture, obstruction, recurrent urinary tract infections and chronic renal failure.
Figure 2 Boari flap with psoas hitch.
bacteriuria’. The threshold for identifying ‘significant bacteriuria’ is based on the work of Kass where the presence of 105 colony forming units per ml (cfu/ml) of a single species of uro-pathogens, is considered diagnostic for cystitis. This threshold was identified by examining the urine of asymptomatic women and as such may represent too high a cut off for diagnosing infection in symptomatic women. Women who are symptomatic with urinary bacterial counts less than 105 cfu, may well have microbial invasion of the lower urinary tract and need treatment for cystitis. The incidence of cystitis following the use of short-term in-dwelling urinary catheterization has been estimated to be 5%. However following pelvic floor repair, the rate of bacteriuria after indwelling catheterization has been shown to be up to 23.7%. The discrepancy between these estimates reflects the varying outcome measures used to diagnose infection. It has also been shown that in approximately one third of patients with asymptomatic bacteriuria following catheterization, that the urine will become sterile within 14 days. A recent Cochrane review has suggested that the use of indwelling catheters that are impregnated with silver alloy, reduces the risk of catheter acquired urinary tract infection, but further economic evaluation is needed. Catheters that are impregnated with antibiotics (minocycline, rifampicin and nitrofurantoin) also reduce bacteriuria, but again further evaluation is required. There are great variations in bladder care practice between gynaecological surgeons. Recent studies have suggested that routine catheterization prior to laparoscopic gynaecological surgery is not necessary.
Bladder dysfunction following gynaecological surgery Over-distension injuries The aim of all post-operative bladder care regimens is to ensure adequate bladder drainage and so avoid over-distension bladder injuries that may result in either an atonic or a hyper-reflexive bladder. Bladder over-distension can be compounded by the use of opiate based analgesics which act centrally and inhibit the normal
Infection The diagnosis of cystitis is based on the presence of clinical symptoms of frequency, urgency, dysuria and supra-pubic discomfort and the identification in the urine of ‘significant
OBSTETRICS, GYNAECOLOGY AND REPRODUCTIVE MEDICINE 21:1
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Ó 2010 Elsevier Ltd. All rights reserved.
REVIEW
bladder emptying cycle. There is little consensus amongst urogynaecologists as to how best to drain the bladder after pelvic floor surgery nor what post-void residual volume is acceptable after removal of the urinary catheter. Variations exist in bladder care after mid-urethral tape surgery, with some surgeons leaving normal saline in the bladder at the completion of the procedure and performing post-void residual measurements after an initial void and other surgeons leaving an indwelling catheter for 24 h post surgery, then performing post-void residuals.
Finally day-to-day post-operative care should be supervised by senior surgical staff.
Conclusion Primary prevention of lower urinary tract injury should be actively pursued as it offers the best chance of success and is associated with the least morbidity and litigation. Anticipation of congenital or acquired anatomical distortion of the pelvic anatomy, should act as a trigger for the gynaecological surgeon to instigate pre-operative investigations and intra-operative precautions, which may involve operating along side a urological surgeon, so as to reduce the risk of urinary tract injury. The presence of flank pain representing ureteric obstruction is not a normal post-operative finding after pelvic surgery. De novo incontinence following hysterectomy should be considered a VVF until proven otherwise. This and other atypical symptoms should trigger suspicion of a urinary tract injury. If an iatrogenic injury has occurred, an apology, along with an explanation, access to remedial treatment and the provision of support for the patient may prevent litigation.
Prolapse surgery and bladder function The development of stress urinary incontinence (SUI) following prolapse surgery is an extensively documented problem. Currently there is no means by which one can predict, which patients will develop de novo SUI following prolapse surgery. Surgeons have therefore attempted to prevent this by performing concomitant prophylactic continence procedures. However the CARE study (n ¼ 305) a randomized controlled trial comparing the outcome of sacrocoplopexy with or without Burch colposuspension found no significant difference in bothersome symptoms of stress incontinence or re-operation rates between the two groups at 12 months. Prolapse can be associated with urinary tract symptoms, overactive bladder and voiding difficulty however some women with prolapse are completely asymptomatic, their prolapse being discovered during routine cervical screening. A recent metaanalysis which includes studies of cystocoele repair, has quantified de novo urinary symptoms that occur after pelvic floor surgery. Overall after prolapse surgery 15% of women reported new subjective stress urinary incontinence, 12% de novo overactive bladder symptoms and new voiding dysfunction were reported 12% of women. Thus significant urinary morbidity may be associated with prolapse surgery and patients should be counselled appropriately before undergoing surgery.
Case study A 40-year-old woman underwent a total abdominal hysterectomy, with ovarian conservation, the indication for which being menorrhagia, resistant to medical treatment. The operation was performed by a Consultant and the operation note read ‘Routine multi-pedicle hysterectomy with 1/0 vicryl through-out. Routine post-operative observations’. Within 24 h of the operation she developed left loin pain which radiated to the groin. There were no other associated symptoms. No investigations were arranged and she was discharged on day 4 despite on-going loin pain. She was readmitted 10 days later because of on-going loin pain. An ultrasound demonstrated a left hydronephrosis and hydroureter. No further imaging was arranged for a further 3 days, when a contrast CT study confirmed distal ureteric obstruction, with normal appearances of the right kidney and ureter. Immediate urological review was requested and on the same day a left sided percutaneous nephrostomy tube was placed and the patient was discharged with this in-situ. A subsequent nephrostogram confirmed complete obstruction of the distal left ureter. Surgery to re-implant the ureter was scheduled for 8 weeks after the initial surgery. A follow-up MAG3 renogram showed that the left kidney was contributing less than 20% of overall renal function, with no evidence of obstruction of the re-implanted ureter. The patient sued her gynaecologist, claiming for damages resulting from a delay in diagnosis of the ureteric obstruction. This case study highlights the need to investigate atypical symptoms, in this case loin pain, following a hysterectomy. Loin to groin pain is not usually a sequelae of gynaecological surgery and requires investigation. A
Litigation Recent studies from Canada have confirmed that the prevalence of urinary tract injury following surgery for benign gynaecological surgery is 0.33% and the risk of litigation from these injuries is 3.0%. The same authors showed that patients who underwent a hysterectomy were 70 times more likely to pursue litigation if there had been a urinary tract injury, than if there had not. Four main reasons have been identified as to why patients take legal action; the need for an explanation, the desire to prevent similar incidents, compensation for pain, suffering and financial losses and the desire to hold individuals and organizations to account for their actions. It is possible to identify a number of key points along a patient pathway, where the risk of iatrogenic injury can be identified and minimized. Specifically it is possible to anticipate some of the risk factors for urinary tract injury (see above), from the GPs letter and during history taking. Multidisciplinary meetings and open communication with radiology departments help to optimize pre-operative assessment. The development of patient information leaflets and appropriate pre-operative consent, allied to high quality documentation of the same, can help to ensure that a complication although unfortunate is not unexpected by the patient or the surgeon. High quality surgical training, high levels of anatomical knowledge and detailed operative notes all help to reduce the risk of iatrogenic urinary tract injury or successful litigation if injury occurs.
OBSTETRICS, GYNAECOLOGY AND REPRODUCTIVE MEDICINE 21:1
FURTHER READING Baggish MS, Karram MM. Atlas of pelvic anatomy and gynecologic surgery. Philadelphia: Elsevier Saunders, 2010. Chapple RC, Turner-Warwick RT. Complex reconstructive surgery. In: Cardozo L, Staskin D, eds. Textbook of female urology and urogynaecology. 2nd edn. Abingdon, Oxon: Informa Healthcare, 2006: 1290e315.
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Ó 2010 Elsevier Ltd. All rights reserved.
REVIEW
Gilmour DT, Baskett TF. Disability and litigation from urinary tract injuries at benign gynecologic surgery in Canada. Obstet Gynecol 2005; 105: 109e14. Gilmour DT, Das S, Flowerdew G. Rates of urinary tract injury from gynecologic surgery and the role of intraoperative cystoscopy. Obstet Gynecol 2006; 107: 1366e72. Harkki-Siren P, Sjoberg J, Tiitinen A. Urinary tract injuries after hysterectomy. Obstet Gynecol 1998; 92: 113e8. Jha S, Coomarasamy A, Chan KK. Ureteric injury in obstetric and gynaecological surgery. Obstet Gynaecol 2004; 6: 203e8. Kass EH. Asymptomatic infections of the urinary tract. Trans Assoc Am Phys 1956; 69: 56e64. Neuman M, Eidelman A, Langer R, Golan A, Bukovsky I, Caspi E. Iatrogenic injuries to the ureter during gynecologic and obstetric operations. Surg Gynecol Obstet 1991; 173: 268e72. Notley RG, Reynard JM, Badenoch J. Urology and the law: lessons from litigation. Abingdon, Oxon, OX14 4RN: Informa UK Ltd, 2007. Robinson D, Gray J. Lower urinary tract infections- simple and complex. In: Cardozo L, Staskin D, eds. Textbook of female urology and urogynaecology. 2nd edn. Abingdon: Informa Healthcare, 2006: 614e30.
OBSTETRICS, GYNAECOLOGY AND REPRODUCTIVE MEDICINE 21:1
Practice points C
C
C
C
C C
C
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Anticipation of congenital or acquired distortion of pelvic anatomy. Consider pre-operative imaging and intra-operative identification of ureters. High clinical suspicion of urinary tract injury for patients presenting with atypical post-operative symptoms e.g. flank pain, watery PV discharge. Low threshold for post-operative imaging and assistance from urologists. Careful adherence to post-operative bladder care guidelines. Prospective review of patient pathways, to identify and reduce risk of urinary tract injury. Following an iatrogenic injury, apologize, explain, initiate remedial action, ensure exemplary documentation and complete a clinical risk management form.
Ó 2010 Elsevier Ltd. All rights reserved.
Urological complications following gynaecological surgery
injury is elevated by the presence of congenital anomalies e.g. horse shoe kidney, or acquired distortions of the pelvic anatomy by adhesions, endometriosis, malignancy, large pelvic masses or previous radiotherapy. Emergency surgery such as caesarean hysterectomy or laparotomy for ectopic pregnancy may involve the need to obtain rapid haemostasis, so the risk of urinary tract damage increases. A bloody operative field may lead to poor visualization of pelvic anatomy and therefore blind clamping of pedicles and placement of sutures. This situation can be compounded by surgical factors such as insufficient anatomical knowledge of the path of the ureter, an inexperienced surgeon or poor surgical techniques. Advances in minimal access surgery have led to an increase in the number of gynaecological procedures being performed by laparoscopy. This requires a high degree of technical ability and dexterity, and so has a significant learning curve. Diathermy is the leading cause of ureteric injury at laparoscopy and the ureter is most vulnerable when the vaginal cuff is taken.
Anna Haestier Robert Sherwin
Abstract Iatrogenic injury of the lower urinary tract occurs during benign gynaecological surgery with a frequency of approximately 0.3%. The injuries sustained are often not detected intra-operatively, but on many occasions, the vulnerability of the urinary tract to injury can be anticipated by rigorous pre-operative assessment and the risk of injury reduced by intra-operative vigilance. Primary prevention offers the best outcome for patients, reducing acute and long-term morbidity, and reducing the risk of litigation. A high index of suspicion must be maintained for patients who present with atypical symptoms such as loin pain or per vaginal clear fluid loss following gynaecological surgery and early recourse to imaging and urological review should be sought. The risk of litigation following iatrogenic urinary tract damage can be reduced by appropriate behaviour of clinicians. Iatrogenic urinary tract infection or bladder over-distension injuries can also be reduced by following evidence based guidelines for cystoscopy and catheterization.
Aetiology of iatrogenic urinary tract damage Estimates of the frequency of ureteric injuries during gynaecological surgery range from 0.002 to 2.5%. The ureter is the most vulnerable part of the lower urinary tract and there are case reports of ureteric damage following most operative gynaecological procedures. Studies suggest that gynaecological surgery accounts for about 75% of all iatrogenic ureteric injuries. The sites of injury are most commonly at the pelvic brim, near to the infundibulo-pelvic ligament and at the pelvic sidewall, where the ureter passes beneath the uterine artery. The majority of injuries occur to the distal ureter (51%), with the upper third damaged in approximately 30% and the middle third in 19% of cases. The ureter may be damaged in several ways including, crushing by a clamp, tethering by a ligature, partial or complete transection, devascularization or indirectly through energy sources, e.g. diathermy, laser or microwave. Bilateral injuries are rare but account for 5% of all ureteric injuries and if they remain unrecognized can be fatal. Bladder injuries occur with frequency of 1e5%, most commonly during reflection of the utero-vesicle peritoneal fold as part of caudal dissection of the bladder. The bladder is as vulnerable as the ureter to indirect damage by energy sources. Previous caesarean section significantly increases the risk of unintentional cystotomy at pelvic surgery, especially during abdominal hysterectomy. The majority of litigation related to bladder injuries follows fistula formation, which is a consequence of suture placement through the bladder during the closure of the vaginal cuff at hysterectomy. Urethral injuries are very rare and their true incidence is unknown. In females the urethra is only 4 cm long, but it is susceptible to damage along its’ entire length during pelvic floor surgery. The most frequent complication is a urethral tear, sustained during catheterization, cystoscopy or urethral diverticulumectomy, which may be complicated by fistula formation.
Keywords bladder perforation; functional bladder disorder; good practice; iatrogenic injury; litigation; over-distension injury; ureteric injury; urinary tract infection
Introduction All gynaecological operations have the potential to injure the lower urinary tract, due to the anatomical proximity of the reproductive tract to the ureters, bladder and urethra. Since the first description of hysterectomy, urinary tract injuries have been reported and this potentially devastating complication continues to plague gynaecological surgeons. Urinary tract trauma is associated with longterm morbidities such as vesico-vaginal fistula, ureteric stenosis, hydronephrosis and renal failure. Although extremely rare, death may result from undetected injuries.
Risk factors for iatrogenic urinary tract trauma Most iatrogenic damage to the urinary tract occurs in patients with conditions that alter the normal pelvic anatomy: The risk of
Anna Haestier BSc (Hons) MBBS PgD MRCOG is a Specialty Trainee 6 in Obstetrics and Gynaecology at Hinchingbrooke Hospital, Huntingdon, Cambridge, UK. Conflicts of interest: none declared.
Preventing iatrogenic injury
Robert Sherwin MA PhD MRCOG is a Consultant Obstetrician and Gynaecologist at the Whittington Hospital, London, UK. Conflicts of interest: none declared.
OBSTETRICS, GYNAECOLOGY AND REPRODUCTIVE MEDICINE 21:1
Damage prevention begins with careful pre-operative patient selection. Conservative and medical treatment options should be given careful consideration in women who may have altered
15
Ó 2010 Elsevier Ltd. All rights reserved.
REVIEW
pelvic anatomy (see above). If pelvic distortion is anticipated preoperative imaging by contrast CT or ultrasound should be used to identify the course of the ureter, to establish any pre-existing renal collection system dilatation and identify pre-existing renal parenchymal damage. These modalities have no role in preventing damage during routine cases. Pre-operative ureteric catheterization or stenting should be considered when pelvic anatomy is distorted, but case reports have highlighted damage to the ureteric mucosa caused by intra-operative manipulation of the ureter with a stent in-situ. Economic evaluation of elective ureteric stenting has been evaluated and appears not to be cost effective in low risk cases therefore it does not have a role in preventing damage during routine elective cases. Intra-operatively many strategies have been used to reduce the risk of iatrogenic damage. Routine exposure of the ureter during abdominal hysterectomy, by retroperitoneal dissection before ligation of the uterine arteries, has been shown to reduce ureteric injury from 0.7% to 0.2%. Some surgeons attempt to palpate the ureter as well as looking for vermiculation, the “wormlike” movement of the ureter. However in obese patients or when the anatomy is distorted, this may not be possible. If there is any doubt about the course of the ureter or position of the bladder once the peritoneum has been opened, a urological opinion should be sought, before continuing with the procedure.
routine gynaecological operations, as bladder injuries may be missed and urethral instrumentation increases the risk of infection. Intra-operative cystoscopy should be only used for complex pelvic floor surgery, cases of malignancy and during operations that have been complicated by distorted anatomy. If urinary tract damage is suspected in the post-operative period, then investigations should include a full blood count and electrolyte profile. A full blood count may show an elevated white cell count with a neutrophilia. Hyponatraemia may be suggestive of free spill of urine into the peritoneal cavity as reabsorption of free water causes a decrease in serum osmolality and serum sodium. A rise in serum creatinine levels beyond the second post-operative day may be indicative of ureteric damage. However this is not specific for damage, as other factors can influence the elevation of this analyte, including inadequate fluid resuscitation and nephrotoxic drugs. Post-operative ureaemia is a sign of either dehydration or total urinary tract obstruction. Failure of this waste product to be cleared from serum following adequate rehydration warrants urgent investigation. Radiological imaging is vital for identification of the site of the urinary tract obstruction or leak (Figure 1). Computer tomography with intravenous contrast is commonly used to check the patency of the entire urinary tract. Radiological features of urinary tract damage include dye extravasation or absence of dye in the urinary tract. Ultrasound is a quick non-invasive test that has great sensitivity for detection of hydronephrosis, and retroperitoneal urinomas, but it cannot be used as the primary diagnostic modality for identification of the course and integrity of the ureter. Intravenous urography has been largely superceded by computed tomography, but still has a role for identification of hydronephrosis, ureteric and bladder patency. Post-operative cystoscopy may be used as an adjunct to radiological imaging. The triple swab test for suspected bladder fistula is a quick
Presentation of urinary tract injury Many injuries such as ureteric tethering or suture placement through the bladder may go unrecognized, as the patient can be asymptomatic. In symptomatic cases, presentations include immediate or delayed post-operative flank pain, fever, peritonitis, haematuria, anuria, ileus, secondary hypertension or urinary leakage through the vagina, abdominal wound or even rectum. Post-operative anuria is most likely caused by hypovolaemia, but it requires prompt investigation as this can be a sign of bilateral ureteric damage. If any of these signs go unnoticed or fail to be investigated then long-term sequelae including fistulas, renal failure or death may occur.
Diagnosis of urinary tract injury If damage occurs, intra-operative recognition and repair ultimately results in the best outcome for the patient, therefore constant checks for the integrity of the urinary tract should be made during gynaecological surgery. Several studies have reported that up to two thirds of cases of ureteric damage go undetected at time of operation. When ureteric damage is suspected, it can be confirmed by several methods. Intravenous administration of indigo carmine or methylene blue can be used to verify ureteric patency, with the passage of dye through both ureteric orifices confirmed by cystoscopy. If there has been no efflux of dye 15 min post injection, the diagnosis of ureteric damage should be suspected. Bubbles or blood exiting through the ureteric orifices may also indicate ureteric damage. Bladder damage is usually more obvious, with overt urinary leakage, visualization of the indwelling catheter or a breach of the bladder being detected during surgery. Many studies have evaluated the role of routine intra-operative cystoscopy for the early diagnosis of bladder damage. These studies have concluded that cystoscopy has limited value as a screening tool during
OBSTETRICS, GYNAECOLOGY AND REPRODUCTIVE MEDICINE 21:1
Figure 1 A 32-year-old woman who presented with vaginal urine leak on day 1 after caesarean section. This antegrade pyelogram shows extravasation of contrast from the distal ureter. A guidewire has been passed through the injured lower right ureter into bladder.
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Ó 2010 Elsevier Ltd. All rights reserved.
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bedside test, which can be performed while waiting for imaging. Three gauze swabs are placed in the vagina and methylene blue dye is instilled transurethral into the bladder. The presence of dye on one of the uppermost swabs indicates the presence of a vesico-vaginal fistula (VVF). If the upper swabs are wet but not blue, this indicates a ureteric fistula.
Management of iatrogenic urinary tract damage The best outcomes occur where urinary tract damage is recognized early and repaired immediately. A surgeon with adequate training, experience and current clinical workload should perform the surgical repair. In most situations this will require the in put of a urologist. The management depends up on the location, mechanism and extent of the injury. For bladder lacerations, the defect should be closed in two layers with an absorbable suture. On completion of the repair the defect must be shown to be watertight by the intravesical administration of dye, e.g. methylene blue. An indwelling catheter should be left in-situ for at least 1 week to decompress the bladder to allow healing. The repair of ureteric damage is more complicated as the choice of surgical technique usually depends on the site of ureteric damage in relation to the bladder, the size of the defect and when the injury is detected. If the ureteric defect is short (<2.5 cm), detected soon after the initial procedure (<3 weeks) and a stent can be placed across the injury, then excellent short and long-term results can be obtained by stenting the ureter. If stenting is not appropriate or possible, then immediate open surgical repair (within 3 weeks) has similar or better results compared to an interval procedure performed at 6 weekse3 months post injury. Percutaneous nephrosotomy drainage should be considered until definitive surgery can be performed, to drain the kidney and reduce inflammation caused by extravasation of urine. If the injury occurs less than 5 cm from the vesico-ureteric junction then uretero-neocystostomy (ureteric reimplantation) should be performed. This procedure involves creating a submucosal tunnel within the bladder. A new urethral orifice is constructed in a watertight fashion and a stent left insitu for 6 weeks. Alternatively a Boari flap (Figure 2) or Psoas hitch can be performed where the defect is covered by a tubularized section of the bladder, so bridging the gap. If the injury is more than 5 cm from the vesico-ureteric junction, then an end-toend anastomosis can be performed with spatulation of the ureteric ends. Complete transection of the ureter with loss of length can be repaired by anastomosis to the contralateral ureter. If a ureter is tethered by a suture, then this should be removed promptly. Thermal injury may lead to tissue ischaemia and so may require excision and ureteric reanastomosis or re-implantation. In cases of complete transection, if the defect is close to the bladder then uretero-neocystotomy can be performed. Following repair a stent should be placed and the bladder drained to facilitate healing. Complications arising from surgery performed to repair damage include a ureteric stricture, obstruction, recurrent urinary tract infections and chronic renal failure.
Figure 2 Boari flap with psoas hitch.
bacteriuria’. The threshold for identifying ‘significant bacteriuria’ is based on the work of Kass where the presence of 105 colony forming units per ml (cfu/ml) of a single species of uro-pathogens, is considered diagnostic for cystitis. This threshold was identified by examining the urine of asymptomatic women and as such may represent too high a cut off for diagnosing infection in symptomatic women. Women who are symptomatic with urinary bacterial counts less than 105 cfu, may well have microbial invasion of the lower urinary tract and need treatment for cystitis. The incidence of cystitis following the use of short-term in-dwelling urinary catheterization has been estimated to be 5%. However following pelvic floor repair, the rate of bacteriuria after indwelling catheterization has been shown to be up to 23.7%. The discrepancy between these estimates reflects the varying outcome measures used to diagnose infection. It has also been shown that in approximately one third of patients with asymptomatic bacteriuria following catheterization, that the urine will become sterile within 14 days. A recent Cochrane review has suggested that the use of indwelling catheters that are impregnated with silver alloy, reduces the risk of catheter acquired urinary tract infection, but further economic evaluation is needed. Catheters that are impregnated with antibiotics (minocycline, rifampicin and nitrofurantoin) also reduce bacteriuria, but again further evaluation is required. There are great variations in bladder care practice between gynaecological surgeons. Recent studies have suggested that routine catheterization prior to laparoscopic gynaecological surgery is not necessary.
Bladder dysfunction following gynaecological surgery Over-distension injuries The aim of all post-operative bladder care regimens is to ensure adequate bladder drainage and so avoid over-distension bladder injuries that may result in either an atonic or a hyper-reflexive bladder. Bladder over-distension can be compounded by the use of opiate based analgesics which act centrally and inhibit the normal
Infection The diagnosis of cystitis is based on the presence of clinical symptoms of frequency, urgency, dysuria and supra-pubic discomfort and the identification in the urine of ‘significant
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bladder emptying cycle. There is little consensus amongst urogynaecologists as to how best to drain the bladder after pelvic floor surgery nor what post-void residual volume is acceptable after removal of the urinary catheter. Variations exist in bladder care after mid-urethral tape surgery, with some surgeons leaving normal saline in the bladder at the completion of the procedure and performing post-void residual measurements after an initial void and other surgeons leaving an indwelling catheter for 24 h post surgery, then performing post-void residuals.
Finally day-to-day post-operative care should be supervised by senior surgical staff.
Conclusion Primary prevention of lower urinary tract injury should be actively pursued as it offers the best chance of success and is associated with the least morbidity and litigation. Anticipation of congenital or acquired anatomical distortion of the pelvic anatomy, should act as a trigger for the gynaecological surgeon to instigate pre-operative investigations and intra-operative precautions, which may involve operating along side a urological surgeon, so as to reduce the risk of urinary tract injury. The presence of flank pain representing ureteric obstruction is not a normal post-operative finding after pelvic surgery. De novo incontinence following hysterectomy should be considered a VVF until proven otherwise. This and other atypical symptoms should trigger suspicion of a urinary tract injury. If an iatrogenic injury has occurred, an apology, along with an explanation, access to remedial treatment and the provision of support for the patient may prevent litigation.
Prolapse surgery and bladder function The development of stress urinary incontinence (SUI) following prolapse surgery is an extensively documented problem. Currently there is no means by which one can predict, which patients will develop de novo SUI following prolapse surgery. Surgeons have therefore attempted to prevent this by performing concomitant prophylactic continence procedures. However the CARE study (n ¼ 305) a randomized controlled trial comparing the outcome of sacrocoplopexy with or without Burch colposuspension found no significant difference in bothersome symptoms of stress incontinence or re-operation rates between the two groups at 12 months. Prolapse can be associated with urinary tract symptoms, overactive bladder and voiding difficulty however some women with prolapse are completely asymptomatic, their prolapse being discovered during routine cervical screening. A recent metaanalysis which includes studies of cystocoele repair, has quantified de novo urinary symptoms that occur after pelvic floor surgery. Overall after prolapse surgery 15% of women reported new subjective stress urinary incontinence, 12% de novo overactive bladder symptoms and new voiding dysfunction were reported 12% of women. Thus significant urinary morbidity may be associated with prolapse surgery and patients should be counselled appropriately before undergoing surgery.
Case study A 40-year-old woman underwent a total abdominal hysterectomy, with ovarian conservation, the indication for which being menorrhagia, resistant to medical treatment. The operation was performed by a Consultant and the operation note read ‘Routine multi-pedicle hysterectomy with 1/0 vicryl through-out. Routine post-operative observations’. Within 24 h of the operation she developed left loin pain which radiated to the groin. There were no other associated symptoms. No investigations were arranged and she was discharged on day 4 despite on-going loin pain. She was readmitted 10 days later because of on-going loin pain. An ultrasound demonstrated a left hydronephrosis and hydroureter. No further imaging was arranged for a further 3 days, when a contrast CT study confirmed distal ureteric obstruction, with normal appearances of the right kidney and ureter. Immediate urological review was requested and on the same day a left sided percutaneous nephrostomy tube was placed and the patient was discharged with this in-situ. A subsequent nephrostogram confirmed complete obstruction of the distal left ureter. Surgery to re-implant the ureter was scheduled for 8 weeks after the initial surgery. A follow-up MAG3 renogram showed that the left kidney was contributing less than 20% of overall renal function, with no evidence of obstruction of the re-implanted ureter. The patient sued her gynaecologist, claiming for damages resulting from a delay in diagnosis of the ureteric obstruction. This case study highlights the need to investigate atypical symptoms, in this case loin pain, following a hysterectomy. Loin to groin pain is not usually a sequelae of gynaecological surgery and requires investigation. A
Litigation Recent studies from Canada have confirmed that the prevalence of urinary tract injury following surgery for benign gynaecological surgery is 0.33% and the risk of litigation from these injuries is 3.0%. The same authors showed that patients who underwent a hysterectomy were 70 times more likely to pursue litigation if there had been a urinary tract injury, than if there had not. Four main reasons have been identified as to why patients take legal action; the need for an explanation, the desire to prevent similar incidents, compensation for pain, suffering and financial losses and the desire to hold individuals and organizations to account for their actions. It is possible to identify a number of key points along a patient pathway, where the risk of iatrogenic injury can be identified and minimized. Specifically it is possible to anticipate some of the risk factors for urinary tract injury (see above), from the GPs letter and during history taking. Multidisciplinary meetings and open communication with radiology departments help to optimize pre-operative assessment. The development of patient information leaflets and appropriate pre-operative consent, allied to high quality documentation of the same, can help to ensure that a complication although unfortunate is not unexpected by the patient or the surgeon. High quality surgical training, high levels of anatomical knowledge and detailed operative notes all help to reduce the risk of iatrogenic urinary tract injury or successful litigation if injury occurs.
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FURTHER READING Baggish MS, Karram MM. Atlas of pelvic anatomy and gynecologic surgery. Philadelphia: Elsevier Saunders, 2010. Chapple RC, Turner-Warwick RT. Complex reconstructive surgery. In: Cardozo L, Staskin D, eds. Textbook of female urology and urogynaecology. 2nd edn. Abingdon, Oxon: Informa Healthcare, 2006: 1290e315.
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Gilmour DT, Baskett TF. Disability and litigation from urinary tract injuries at benign gynecologic surgery in Canada. Obstet Gynecol 2005; 105: 109e14. Gilmour DT, Das S, Flowerdew G. Rates of urinary tract injury from gynecologic surgery and the role of intraoperative cystoscopy. Obstet Gynecol 2006; 107: 1366e72. Harkki-Siren P, Sjoberg J, Tiitinen A. Urinary tract injuries after hysterectomy. Obstet Gynecol 1998; 92: 113e8. Jha S, Coomarasamy A, Chan KK. Ureteric injury in obstetric and gynaecological surgery. Obstet Gynaecol 2004; 6: 203e8. Kass EH. Asymptomatic infections of the urinary tract. Trans Assoc Am Phys 1956; 69: 56e64. Neuman M, Eidelman A, Langer R, Golan A, Bukovsky I, Caspi E. Iatrogenic injuries to the ureter during gynecologic and obstetric operations. Surg Gynecol Obstet 1991; 173: 268e72. Notley RG, Reynard JM, Badenoch J. Urology and the law: lessons from litigation. Abingdon, Oxon, OX14 4RN: Informa UK Ltd, 2007. Robinson D, Gray J. Lower urinary tract infections- simple and complex. In: Cardozo L, Staskin D, eds. Textbook of female urology and urogynaecology. 2nd edn. Abingdon: Informa Healthcare, 2006: 614e30.
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Practice points C
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Anticipation of congenital or acquired distortion of pelvic anatomy. Consider pre-operative imaging and intra-operative identification of ureters. High clinical suspicion of urinary tract injury for patients presenting with atypical post-operative symptoms e.g. flank pain, watery PV discharge. Low threshold for post-operative imaging and assistance from urologists. Careful adherence to post-operative bladder care guidelines. Prospective review of patient pathways, to identify and reduce risk of urinary tract injury. Following an iatrogenic injury, apologize, explain, initiate remedial action, ensure exemplary documentation and complete a clinical risk management form.
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