Ureteral Reimplantation

What the Anesthesiologist Should Know before the Operative Procedure

Ureteral reimplantation is usually performed to treat high grade (Grade III-V) vesicoureteral reflux (VUR), where reflux is associated with calyceal blunting and, at times, ureteral dilatation. Untreated VUR can result in chronic/recurrent UTIs, renal scarring, renal insufficiency, hypertension, and impaired somatic growth.

The incidence of VUR is 1-3% in healthy children, but increases to 30-50% in children with symptomatic UTIs. VUR occurs more commonly in females and Caucasians. Genetic factors may play a role, as there is a 30-50% incidence in siblings and a 67% incidence in offspring of affected individuals.

VUR produces retrograde flow of urine from the bladder through the ureter and, at times, into the kidney. Primary VUR is a congenital anomaly resulting from development of an inadequate valvular mechanism at the ureterovesical junction. Secondary VUR is caused by anatomic or functional bladder outlet obstruction. Diagnosis is generally made by renal ultrasound and voiding cystourethrogram.

1. What is the urgency of the surgery?

What is the risk of delay in order to obtain additional preoperative information?

VUR may be diagnosed prenatally or in childhood. Renal failure is uncommon, with an estimated risk of <1%. Hence, the majority of surgical procedures are performed electively by 5-6 years of age. There is generally no significant increase in risk associated with delaying surgery in order to obtain additional preoperative information or to optimize the patient for surgery, if deemed necessary.

Emergent: N/A. Ureteral reimplantation is not emergent

Urgent: N/A. Ureteral reimplantation is not urgent surgery

Elective: Most patients with VUR are initially managed on low-dose prophylactic antibiotics, as 70-90% of low grade reflux will resolve spontaneously. Indications for surgery include breakthrough UTIs while on antibiotics, noncompliance, increasing or severe reflux, deteriorating renal function, persistent reflux in females approaching puberty, and congenital anomalies of the ureterovesical junction.

2. Preoperative evaluation

Most patients are healthy children (ASA I-II), but some have significant congenital anomalies (e.g., spinal dysraphism) or GU anomalies (e.g., UPJ obstruction, ureteral duplication, bladder diverticula, posterior urethral valves, or bladder or cloacal exstrophy). The anesthesiologist should obtain a thorough history and physical examination looking for evidence of, as well as laboratory evaluation for, renal insufficiency.

• Medically unstable conditions warranting further evaluation are generally not present in patients who present for elective ureteral reimplantation.

• Delaying surgery may be indicated if the patient is not medically optimized in terms of cardiopulmonary status.

3. What are the implications of co-existing disease on perioperative care?

N/A

b. Cardiovascular system

Acute/unstable conditions

• N/A. This is an elective surgery and should not be performed in an acutely ill or unstable patient.

Baseline coronary artery disease or cardiac dysfunction

• Patients are generally children without history of coronary artery disease or cardiac dysfunction. Hypertension may be present in the setting of renal scarring from VUR, but this generally takes years to develop. Preoperative evaluation should involve a physical exam to assess the presence of a heart murmur as well as noninvasive measurement of blood pressure. If a heart murmur is appreciated, the patient should be evaluated for the presence of structural heart disease by EKG, echocardiology, or a cardiology consult if appropriate.

c. Pulmonary

COPD

• Generally not present unless patient were to have chronic lung disease related to prematurity, cystic fibrosis, etc.

Reactive airway disease (Asthma)

• Asthma is not associated with VUR per se, but may be present in up to 10% of children in the USA. Children with asthma requiring ureteral reimplantation should have their pulmonary status optimized preoperatively with the use of beta agonists, steroids, and leukotriene-receptor antagonists as appropriate. Preoperative evaluation involves physical examination to assess for signs or symptoms of active reactive airway disease, including tachypnea or wheezing. If symptomatic, surgery should be delayed.

d. Renal-GI:

While reflux nephropathy is reportedly the fourth most common cause of chronic renal insufficiency in children, most children who present for ureteral reimplantation do not have renal insufficiency. However, patients with underlying congenital genitourinary anomalies, such as posterior urethral valves, may be at higher risk for renal insufficiency or renal tubular acidosis. Preoperative assessment should include a measurement of serum electrolytes, BUN, and creatinine.

e. Neurologic:

Acute issues

• Generally N/A.

Chronic disease

• Patients with meningomyelocoele/spina bifida who present for ureteral reimplantation may have bowel or bladder dysfunction, as well as baseline weakness or paralysis. In addition to postoperative considerations, the presence of neurologic disease may impact on anesthetic choice, including the avoidance of neuraxial analgesia in patients with spinal dysraphism. Preoperative assessment should include a neurologic exam as well as physical examination looking for signs of spina bifida occulta (sacral dimple or hair tuft).

f. Endocrine:

In general, patients who present for reimplantation surgery do not present with associated endocrinologic pathology.

g. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (e.g., musculoskeletal in orthopedic procedures, hematologic in a cancer patient)

There are no additional specific organ systems/conditions specifically associated with reimplantation surgery.

4. What are the patient's medications and how should they be managed in the perioperative period?

N/A

h. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?

• Many patients will present for surgery on chronic antibiotic prophylaxis given concerns regarding the risk of urinary tract infection, but will otherwise not be routinely taking medications unless they have an additional medical problem.

i. What should be recommended with regard to continuation of medications taken chronically?

• Cardiac – If the patient is being treated for hypertension, ACE inhibitors should be held preoperatively.

• Pulmonary – Chronic medications for reactive airway disease, if present, should be continued.

• Renal – If present, continue all medications, unless particulate antacids are utilized.

• Neurologic – Generally N/A.

• Anti-platelet – If patient is taking NSAID’s, discontinue prior to surgery.

• Psychiatric – Generally N/A.

j. How To modify care for patients with known allergies –

N/A

k. Latex allergy- If the patient has a sensitivity to latex (eg. rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.

Patients who present for surgery with a history of spinal dysraphism or bladder exstrophy are at increased risk for latex allergy. History of any prior reaction to natural rubber latex should be elicited and exposure to latex-containing products should be avoided.

l. Does the patient have any antibiotic allergies- [Tier 2- Common antibiotic allergies and alternative antibiotics]

N/A

m. Does the patient have a history of allergy to anesthesia?

Malignant hyperthermia

Documented

• avoid all trigger agents, such as succinylcholine and inhalational agents.

  Proposed general anesthetic plan: As with all patients with a history of malignant hyperthermia, general anesthesia using intravenous agents (e.g., propofol, nondepolarizing muscle relaxants, and opioids) +/- nitrous oxide +/- neuraxial anesthesia is an appropriate choice. In addition, intraoperative temperature monitoring (usually a late sign), a “clean” anesthesia machine, and availability of supplies to treat malignant hyperthermia (e.g., MH cart) should be available and utilized as necessary.

Family history or risk factors for MH

• While both muscle biopsy and genetic testing can be useful in diagnosing malignant hyperthermia in a patient given a positive family history, most patients will not present having already obtained a muscle biopsy, and negative genetic testing does not necessarily rule out malignant hyperthermia. Therefore, when there is a positive family history of malignant hyperthermia, a non-triggering anesthetic is generally recommended.

Local anesthetics/ muscle relaxants

• While rare, the medications in question should be avoided in any patient with a prior history of allergic reaction to local anesthetics, muscle relaxants, or opioids.

5. What laboratory tests should be obtained and has everything been reviewed?

Serum electrolytes, BUN, and creatinine should be obtained preoperatively. Additional tests should be obtained based on the patient’s history.

Common laboratory normal values will be same for all procedures, with potential differences based on age and gender.

• Hemoglobin levels: 13.2-15.6 g/dL.

• Electrolytes: Sodium 135-148 meq/L; Potassium 3.5-5.1 meq/L; Chloride 96-109 meq/L; Bicarb 21-31 meq/L; Blood Urea Nitrogen 7-22 mg/dL; Creatinine: 0.6-1.3 mg/dL.

• Coagulation panel: PT 9.5-12.3 seconds; PTT 22.4-29.5 seconds (varies somewhat by institution).

Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?

General endotracheal anesthesia alone or in combination with neuraxial anesthesia are both effective intraoperatively.

a. Regional anesthesia

Neuraxial

• Benefits – Potentially improved perioperative analgesia and opioid sparing.

• Drawbacks – Regional anesthesia alone is not generally advocated given patient age, as the patient may not remain calm and still intraoperatively. Combined techniques can be used in patients for reimplantation surgery, although they are generally not employed in patients with associated spinal dysraphism.

Peripheral Nerve Block

• This is not appropriate for this surgery.

b. General Anesthesia

• Benefits – Still surgical field.

• Drawbacks – Postoperative nausea and vomiting.

• Airway concerns – In general, patients require endotracheal intubation for open procedures. LMA may be appropriate when low grade reflux is treated by an injection of Deflux.

c. Monitored Anesthesia Care

Given patient age and the nature of the surgery, monitored anesthesia care is not an option.

6. What is the author's preferred method of anesthesia technique and why?

What prophylactic antibiotics should be administered?

Patients without allergy to antibiotics are generally administered ampicillin (50 mg/kg by slow IV push) and gentamicin prophylactically before skin incision. In patients who have a penicillin or cephalosporin allergy, clindamycin (10 mg/kg over 10 to 20 minutes) can be administered in place of ampicillin. Ampicillin is redosed every 3 hours and clindamycin is redosed every 6 hours. While standard pediatric dosing of gentamicin is as high as 5 mg/kg (administered over 30 minutes and not redosed), frequently we administer a lower dose of gentamicin (1 mg/kg),keeping in mind that the antibiotic will be concentrated in the urine.

What do I need to know about the surgical technique to optimize my anesthetic care?

The goal of reimplantation surgery is the creation of a valvular mechanism that allows ureteral compression with bladder filling and contraction. Open surgical techniques (ureteroneocystostomy) can be extravesical, intravesical, or combined, depending on the approach to the ureter, and suprahiatal or infrahiatal, depending on the position of the new submucosal tunnel in relation to the original hiatus.

Extravesical repairs leave the bladder intact, lessening the risk of urinary contamination, bladder spasms, and hematuria, but concerns exist about disrupting bladder innervation and causing urinary retention with bilateral reimplantation. Surgery is generally performed through a Pfannensteil incision, but repairs can be performed through small suprapubic incisions if minimally invasive surgical techniques are utilized.

Laparoscopic repairs are not generally employed, but a pneumovesical approach to reimplantation of the ureters has been reported. Finally, endoscopic injection of the dextranomer/hyaluroic compound (Deflux), a closed surgical treatment of VUR, is an option. It is >70% effective in treating low grade reflux, but has an increased likelihood of failure with increased severity of reflux.

What can I do intraoperatively to assist the surgeon and optimize patient care?

In general, adequate muscular relaxation with inhalation anesthetics +/- neuromuscular blocking agents assists the surgeon. In addition, given the risk of ureteral edema and obstruction, generous hydration resulting in brisk urine output is helpful to the surgeon, as it allows him/her to monitor for signs of ureteral obstruction.

What are the most common intraoperative complications and how can they be avoided/treated?

Prioritize complications by urgency. Perioperative blood loss is generally minimal, and mortality is extremely rare.

Cardiac complications

None specifically related to surgery.

PulmonaryM

None specifically related to surgery.

Neurologic

None specifically related to surgery.

a. Neurologic

• Unique to procedure: None specifically related to surgery.

b. If the patient is intubated, are there any special criteria for extubation?

In general, extubation is attempted at the conclusion of the surgical procedure following reversal of neuromuscular blockade. Routine criteria are employed.

c. Postoperative management

What analgesic modalities can I implement?

Postoperative pain can be incisional or related to bladder spasms and may require treatment with oral or intravenous opioids, anticholinergics, and bladder smooth muscle relaxants (e.g., oxybutinin and diazepam). In addition, local infiltration of skin incisions can be performed before skin closure to aid in initial postoperative analgesia.

When a combined technique (general anesthesia with a single shot caudal or caudal/lumbar epidural catheter inserted following induction) is employed, both intraoperative and postoperative analgesia can be provided via epidural local anesthetics and/or opioids and/or clonidine. If bleeding is not a concern, ketorolac has also been shown to provide analgesia and decrease the frequency and severity of bladder spasms.

What level bed acuity is appropriate?

Most patients who undergo reimplantation surgery are healthy ASA I-II children who do not require recovery in an intensive care unit setting. When open procedures are performed, patients often receive intravenous opioids via IV patient controlled analgesia or continuous epidural analgesia, and they are admitted to a monitored floor bed postoperatively.

Deflux injections to treat low-grade VUR as well as some minimally invasive extravesicular repairs can be performed on an outpatient basis. Prior to discharge, however, patients must demonstrate adequate pain control, tolerance of a regular diet, ability to void postoperatively or comfort with the care of an indwelling ureteral catheter, and the ability to ambulate without difficulty.

What are common postoperative complications, and ways to prevent and treat them?

Complications of surgery include ureteral obstruction, which can be caused by edema, bleeding or blood clots, bladder spasms, or ureteral ischemia. Obstruction is usually asymptomatic and resolves spontaneously. However, symptomatic obstruction can occur, presenting with abdominal pain, nausea, and vomiting. It is usually diagnosed on postoperative follow-up renal ultrasound.

Disruption of bladder innervation is possible, especially with extravesical repair. Additional complications may relate to postoperative pain management and can include ileus, respiratory depression, sedation, emesis, and urinary retention. Analgesic techniques that diminish opioid use by providing alternate approaches to analgesia (neuraxial, NSAID’s, etc.) can be used to minimize these complications.

What's the Evidence?

Khoury, A, Bagli, DJ, Wein, AJ, Kavoussi, LR, Novick, AC, Partin, AW, Peters, CA. “Reflux and Megaureter”. Campbell-Walsh Urology Ninth Edition. 2007. pp. 3423-3481. (Urology textbook chapter providing an overview of the demographics (patient characteristics), diagnosis, evaluation, and medical and surgical management of vesicourereteral reflux.)

Monitto, CL, Roizen, MF, Fleisher, LA. “Ureteral Reimplantation”. Essence of Anesthesia Practice Second Edition. 2002. pp. 482(Abbreviated review focusing on patient assessment, surgery, and perioperative management for the anesthesiologist caring for patients undergoing ureteral reimplantation.)

Chamie, K, Chi, A, Hu, B, Keegan, KA, Kurzrock, EA. “Contemporary open ureteral reimplantation without morphine: assessment of pain and outcomes”. J Urol . vol. 182. 2009. pp. 1147-51. (A non-blinded study evaluating postoperative pain and outcomes (length of stay and recurrence) following minimally invasive ureteral reimplantation surgery in children.)

Hedman, P, Palmer, JS. “A critical pathway for successful outpatient ureteral reimplantation; a nursing perspective”. J Perianesth Nurs . vol. 24. 2009. pp. 163-6.

Chung, PHY, Tang, DYY, Wong, KKY, Yip, PKF, Tam, PKH. “Comparing open and pneumovesical approach for ureteric reimplantation in pediatric patients – a preliminary review”. J Pediatr Surg . vol. 43. 2008. pp. 2246-49. (A retrospective study comparing open and laparoscopic ureteral reimplantation. The laparoscopic approach was associated with shorter hospital stays and was felt to be more cost effective.)

Kawauchi, A, Naitoh, Y, Soh, J, Hirahara, N, Okihara, K, Miki, T. “Transvesical laparoscopic cross-trigonal ureteral reimplantation for correction of vesicoureteral reflux; initial experience and comparisons between adult and pediatric cases”. J Endourol . vol. 23. 2009. pp. 1875-8. (A case series evaluating the minimally invasive transvesical laparoscopic cross-trigonal approach to ureteral reimplantation.)

Rossini, CJ, Moriarty, KP, Courtney, RA, Tashjian, DB. “Endoscopic treatment with deflux for refluxing duplex systems”. J Laparoendosc Adv Surg Tech A.. vol. 19. 2009. pp. 679-82. (A non-randomized report of using Deflux in patients with duplex systems and reflux. Overall success rate after < 3 injections was noted to be 94%.)

Onol, FF, Akbas, A, Erdem, MR, Onol, SY. “Lich-Gregoir ureteral reimplantation with fixation of ureter during detrusorraphy as a reliable outpatient anti-reflux procedure”. Eur J Pediatr Surg . vol. 19. 2009. pp. 320-4. (A non-randomized report of 97 children undergoing the Lich-Gregoir surgical approach to ureteral reimplantation. 81% of children treated were managed as outpatients. 98% of patients had resolution of VUR following surgery.)

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