61-year-old female who was being treated for a UTI due to blood in her urine was experiencing increased pain after 3 days of prescribed medication from an urgent care. She goes to hospital, work up reveals acute kidney injury and pyelonephritis. Blood cultures came back positive for infection, was given IV hydration, antibiotics. While at the hospital, she was found to be positive for COVID and was given Remdesivir. Hospital course shows that she improved kidney function, however a lasix renogram by urology shows a possible left UPJ obstruction. Urology clears for discharge with planned follow-up. She sees a urologist who schedules her for a left pyeloplasty. This is performed on August 31st, 2022 without complication, but there are noted “crossing vessels” around the ureter. It is noted that she will have the stent for 6 weeks prior to removal.
**OP NOTE BELOW**
Upon arriving for stent removal, MD places the cystoscope into the bladder (under direct vision) and inspected without being able to locate the distal portion of the stent. Office note states: “Unable to determine if the stent has retracted into the ureter or self-expulsion?” They perform a KUB and if is retracted, they “will need to perform a ureteroscopy”. The KUB reveals that the “urinal stent proximal pigtail is overlying the expected location of the renal pelvis and distal pigtail is overlying near the location of the left ureteropelvic junction and it's unclear if the stent is within the bladder”. They recommend CT scan for evaluation. MD elects to not do a CT scan, however they perform a ureteroscopy and stent retrieval without complication on November 3rd, 2022. According to the notes, the “incisions are healing well” and they schedule an office visit, urine culture, and a Lasix renogram for 3 months. An unscheduled office visit in December reveals that her urine cultures are negative but still continues to have left side of kidney pain. She's given oral antibiotics and is frustrated by the fact that she feels like she has a urinary tract infection, but does not appear to have one.
PC attempted a second opinion in February, in which they performed a cystoscopy and left retrograde pyelogram. This reveals severe and recurrent left UPJ obstruction and left hydronephrosis. Renal function estimated at 11%. This urologist informs PC that due to severe atrophy, kidney removal would be the only option. The organ was not salvageable.
Left kidney was removed on March 31st, 2023. Despite the obvious change in renal function, there appears to be no other residual acute effects on PC.
Stent migration appears to be a rare complication, but was it managed properly? Were there any opportunities for the original urologist to save the kidney? Any other beaches of the standard of care?
ORIGINAL OP NOTE:
Procedure Details: Patient was properly identified and brought back to the operating suite where she was placed supine on the operating table. A proper time-out was performed. She was placed under general anesthetic. A 16 French Foley catheter was placed by the nursing staff. Ancef 2 g IV were given within 1 hours start procedure. She was placed in right lateral decubitus position, the table was appropriately flexed, and all pressure points were padded. She was prepped and draped in normal sterile surgical fashion. A stab incision was made superior and lateral to the umbilicus triangulated between the 11th rib and xiphoid process. Veress needle was carefully passed into abdominal cavity and its correct position was confirmed. Under direct visualization, I passed a 8 mm robotic trocar into abdominal cavity without any difficulty. The abdominal cavity was carefully inspected and there was no evidence
of any intra-abdominal injury or bleeding. Three other ports were placed all under direct visualization. This included a 8 mm robotic port in the left upper quadrant, a 8 mm robotic port in the left lower quadrant and a 8 mm AirSeal assistant port in the midline superior to the umbilicus. The robot was docked on her left side. I began by reflecting the colon medially by taking down the white line of Told!. The large dilated left renal pelvis was easily identified. I found the left gonadal vein and left ureter inferiorly and followed the structures cephalad. The gonadal vein was divided and ligated. This helped exposed the left ureter and the ureteropelvic junction. There were 2 anterior crossing vessels to the ureter. One of them was a lower pole renal artery the other was a renal vein. The ureter and renal pelvis was completely
mobilized. In order to help with this dissection. A Keith needle was passed through the
anterior abdominal wall, through the left renal pelvis, and brought back up through the anterior abdominal wall to help with retraction. Once the ureter and renal pelvis was completely mobilized, I divided the ureter at its insertion to the renal pelvis. I excised approximately 2 cm of proximal ureter. The ureter was speculated and a tension-free watertight anastomosis was performed anterior to the crossing vessels with the proximal ureter to the renal pelvis using 3-0 V lock. Prior to finishing the anastomosis, a 6 x 26 double-J stent was backloaded and placed in the left ureter with an appropriate curl in the left renal pelvis. The stent was placed without difficulty. The anastomosis was completed over the stent. No leakage was noted. The Keith needle was removed and the kidney went back to its normal location. Tisseel and Arista were used to reinforce hemostasis. The intra-abdominal pressure was brought down to 7 and there
was no bleeding noted. A JP drain was placed through the left lower quadrant incision. The remaining ports removed under direct visualization. Skin incisions were closed with Monocryl and Dermabond. All counts were correct. She was extubated and sent to recovery in stable condition without immediate complications. The stent will stay in place for 6 weeks and be removed on an outpatient basis.
Initial Lasix urogram results:
Blood flow relative to flow in aorta: Prompt, with asymmetrically less to the left kidney.
Relative uptake (split function): Left 36%; Right 64%.
Activity at 20 minutes/maximum activity occurring between 0-20 minutes: Left 40%;
Right not applicable. (Values obtained using a region of interest drawn around the
whole kidneys .. )
Time to peak activity: Right 4 minutes. Left 36 minutes. Normal right renal cortical
extraction and excretion. Severely delayed left renal cortical extraction, with no
discernible excretion.
Diuretic T 1/2: Right not applicable (normal prediuretic). Normal right collecting systems
clearance. Left not applicable (continuously increasing renogram). No discernible left
renal collecting systems activity throughout the exam.
Post void and delayed images: Left cortical retention without detectable collecting
systems activity.
IMPRESSION:
1.
Severe left UPJ obstruction. Severely impaired left renal cortical function.
2. Normal right renal cortical function, negative for right-sided obstruction.
Files:
Q: what was renal function on original lasix renal scan?
A: Relative uptake range: 42%-58% Activity at 20 min: Whole kidney: <55% Cortex: <35% Time to peak activity: Whole kidney: <9.8 minutes Cortex: <3.6 minutes Time to 1/2 peak activity: Whole kidney: <17 minutes Cortex: <9 minutes
Do you believe there might have been medical error?
I would want to know what the original lasix scan showed in terms of her kidney function to have a better sense if there truly was significant kidney loss leading to the nephrectomy. A stent migration can occur and is rare but does not always mean there was malpractice or a deviation from standard of care. However, it is important to note if the stent position was confirmed immediately after the procedure to know it was placed appropriately.
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
I don't believe so based on the facts provided. This impression may change with more information. It's possible that original stent placed was not done correctly and wasn't positioned appropriately and this was not a migration of the stent and rather a case of incorrectly positioned stent from the beginning.
What makes you a good expert for this case?
As a board-certified, fellowship trained urologic surgeon who performs these procedures, I believe I can provide insight and expertise as to the all the aspects of the care provided and possible deviations from standard of care which may have occurred.
How often do you encounter cases similar to this one in your practice?
I encounter similar cases every few months.
Do you believe there might have been medical error?
There may have been an incorrectly sized stent placed which may have exacerbated the obstruction. This may have led to worsening function of the kidney. I would need to review images etc. to determine this.
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
see above. The details and imaging from stent placement would need to be reviewed.
What makes you a good expert for this case?
see cv, I have reviewed similar cases to this before.
How often do you encounter cases similar to this one in your practice?
occasionally, this is not uncommon and I have managed this in my clinical practice.
Do you believe there might have been medical error?
No issues with surgery. In my opinion evaluation and procedure done correctly I did them open but robotic acceptable alternative. Stent migration not uncommon and I have done the same thing by taking patient back for ureteroscopy and removal. This would not be a cause for re stenosis of the UPJ. There is always a risk of restricture after repair The one issue that may be of concern is not getting an imaging study earlier. I usually get a renal ultrasound 4 weeks after stent removal but this may or may not have discovered obstruction. Once the patient still complained of flank pain I would have gotten the renal scan earlier. Again this may or may not have identified obstruction. I cannot say whether the kidney was salvageable without seeing films. Assuming reasonable renal tissue relief of obstruction with a stent or perc and then a scan might have shown better recovered function. If not then nephrectomy may be needed
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
The medical error in my opinion is not getting an upper tract study earlier especially if patient had flank pain The procedures were performed correctly
What makes you a good expert for this case?
Although I am retired from full time practice I have 35 years of Urology experience and have seen similar results.
How often do you encounter cases similar to this one in your practice?
Not often where loss of function requiring nephrectomy occurs. Rare ID of recurrent stenosis resulting in redo pyeloplasty
Do you believe there might have been medical error?
The indications for the procedure were correct. This seems to be a case of ureteral stent migration. The only potential flaw was that there wasnt a KUB to determine the distal portion of the stent was placed in correctly in the bladder. Regardless, i do not think that would make a difference The thing that seems odd is that fact that there was such a significant difference in renal function in such a short period (90days) of time. I would have placed a nephrostomy tube at the time that the 2nd renal scan was done and then reassess the kidney function after 3 months. If indeed there was no improvement the nephrectomy was indicated , however if there was an improvement in the obstruction, then perhaps a repeat pyeloplasty instead of a nephrectomy could have been performed. The other question is if the original renal scan was interpreted correctly. Perhaps the original reading of the first renal scan was not correct and more liekly it may have been overread
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
The correct steps were taken by the surgeon Stent migration is a known complication of utilizing stents. The real question is what I pointed out above. Perhaps the nephrectomy needed to be done originally The original films need to be reevaluated. Or perhaps there was an overzealous surgeon willing to do a nephrectomy
What makes you a good expert for this case?
I have been practicing for 3o years. I have previously published on UPJ obstruction in a sentinel article about UPJ obstruction
How often do you encounter cases similar to this one in your practice?
Pyeloplasties have a known low failure rate. This is uncommon but I have seen it before
Do you believe there might have been medical error?
The surgical technique as documented in the operative note was meticulous without any obvious errors. Whether or not the surgeon had measured the ureteral length by some means preoperatively, there was no mention of this. While this is not necessarily part of standard care, in my practice, I always measure the ureteral length based on pre-operative CT scan in order to determine the optimal stent size for insertion. In this case, it appears that the chosen 6 fr x 26 cm ureteral stent was too short to reach the bladder. This may have been the case, for example, if the patient had an abnormally positioned cephalad kidney, or suffering from an occult cystocele with caudal displacement of the ureterovesicle junction. Another potential criticism, while certainly not standard of care, would have been to obtain some type of imaging to ensure optimal stent positioning when the patient presented earlier than planned follow-up with complaints of UTI symptoms with a negative culture. Due to the poor outcome in this case, it appears that the stent was never positioned properly and in fact was probably not even traversing across the re-anastomosed ureteropelvic junction, thereby leading to recurrent high-grade obstruction and ultimate renal demise.
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
Regrettably, in this case the outcome was less than optimal nor expected and the patient lost the kidney. Based on review of the operative record, the surgery was performed within accepted standards of care parameters. The only shortfall was the misplaced stent. In very few high volume expert hands, there have been reports of shorter indwelling duration, or even stent-less, pyeloplasty. This is certainly not standard of care and not something I do or recommend on a routine basis. The erroneous placement of a poorly fitted stent, as well as not performing appropriate imaging evaluation when the patient presented with unexpected symptoms post-operatively, may have led to a sub-optimal outcome in this case.
What makes you a good expert for this case?
I have over 15 years experience performing robotic assisted laparoscopic urologic surgery, as well as hundreds of cases of robotic surgeries, including robotic assisted laparoscopic pyeloplasty.
How often do you encounter cases similar to this one in your practice?
I routinely perform anywhere between two to four robotic assisted laparoscopic pyeloplasties per month in my practice.
Do you believe there might have been medical error?
Clearly, the patient had a recurrence of her iridal pelvic junction obstruction. This is known to happen at a relatively low rate. This is likely secondary to a technical problem with the anastomosis, which either scarred down, secondary to a loss of blood flow to the ureter or renal pelvis, or simply due to, a technical problem with the anastomosis itself. I suspect the malposition of the stent to be a red herring. I do not think it retracted at all. It likely it was never placed down into the bladder at the time of surgery. This is relatively common as there is no way on the table to determine if the stent actually Goes all the way down to the bladder. Many times we do get a KUB either in the recovery room or the day after to check for stent placement. Additionally, many times urologist will use an extra long stent in an effort to avoid this problem. Regardless, she did not have pain postoperatively from obstruction , and thus I suspect urine was flying down the ureter without difficulty.
Do you believe there might have been causation (i.e. the medical error resulted in an injury)?
Although her left kidney was compromised, it was salvageable with a pilot plasty, which was performed. Unfortunately, after her stent removal, she had persistent pain, which was due to chronic obstruction, secondary to the failure of her repair. This likely led to a decrease in overall function of that kidney, as noted by the renogram.
What makes you a good expert for this case?
As a generally urologist, we do see patients with the pelvic junction obstructions on a regular basis. I have cared for these patients and understand the issue with stent placement at the time of surgery.
How often do you encounter cases similar to this one in your practice?
My group probably does 3 to 4 similar procedures annually.
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