View as “PDF version”
Patient Safety Tip of the Week
December 5, 2023
Thermal Injuries
During Surgery
We’ve done several
columns on iatrogenic thermal injuries (see list below). But one type is
particularly bothersome – thermal injury that goes initially unrecognized
during surgery. Such cases typically present after a delay of several days. A
couple cases are illustrative.
40-year-old woman
with chronic pelvic pain, history of chronic pelvic inflammatory disease, and
recent severe menorrhagia underwent laparoscopic hysterectomy and bilateral salpingo-oopherectomy. No significant complications were
recognized during the procedure. An indigo dye test was performed before ending
the procedure and it was negative (and on return to the floor dye was
appropriately noted in the Foley catheter). There was some liquid vaginal discharge
post-op but was felt that the drainage was simply from irrigation fluid that
had not fully drained, and she was discharged from the hospital. Three days
after discharge a phone call from the gynecologist to the patient noted there
was continuing vaginal fluid leakage. The urologist performed cystoscopy and a
retrograde pyelogram. The right ureter was patent but
there was leakage of dye from the left ureter. An attempt to put a stent into
the left ureter was unsuccessful so the patient underwent surgical
reimplantation of the left ureter 7 days after the original surgery. There was
no leakage immediately after that surgery but several days later leakage recurred. Clear yellow discharge from the vagina
persisted and CT scan revealed leakage of contrast from the right ureter. She ultimately
had placement of a percutaneous nephrostomy tube into the right ureter and
placement of a stent from above to below.
A 36-year-old female patient with a history of chronic pelvic pain had a
laparoscopic-assisted vaginal hysterectomy with bilateral tubal ligation and
endometrial ablation. However, she had persistent pelvic pain that was
unresponsive to analgesics and several courses of GnRH agonist therapy. She
eventually had a laparoscopic procedure for fulguration of any possible foci of
endometriosis and lysis of adhesions. Some minor bleeding was noted on the left
side. Monopolar cautery was used. Estimated
blood loss was minimal. Approximately one week later she suddenly developed
suprapubic and left abdominal pain associated with nausea and diaphoresis.
Transurethral ultrasound showed fluid in the pelvis and abdomen and a right
ovarian cyst. CT scan with IV and oral contrast showed generalized ascitic
fluid and the bladder appeared intact. There was no hydronephrosis. It was
suspected that she likely had an injury to her ureter, perhaps a thermal injury
related to the prior surgery. But cystoscopy showed no ureteral injury.
Instead, it showed a likely thermal bladder injury on the posterior wall of the
bladder about 2” from the trigone. A Foley catheter was inserted
and she was sent home on Bactrim. However, she returned several days later with
sudden onset of suprapubic pain and CT scan showed the Foley catheter
transecting her bladder with ascites and free air in the retroperitoneum. She
went to the OR where the Foley catheter was removed and necrotic tissue at the
perforation site was removed. The bladder defect was closed surgically
and a new Foley catheter inserted. She was discharged with a plan to repeat a
cystogram prior to Foley removal in about a week.
The incidence of ureteral injury during hysterectomy was
estimated to be 0.2%-6% depending on the type of operation performed, noting
that most ureteral injuries are under-reported and only 30% are recognized
during the surgery (Brotherton
2008). Oh and colleagues (Oh
2000) reviewed the charts of 12 women who had delayed recognition of
ureteral injuries. Patients presented with fever,
hematuria, flank pain, or peritonitis between 3 and 33 days postoperatively.
The mechanism of ureteral injuries was related to electrocoagulation in seven of
these.
Of course, it’s not
just ureters and bladders that are prone to thermal injury. Any hollow viscus
can be affected. Thermal injuries to bowel are especially dangerous
because of the havoc raised by fecal contents spilling into the peritoneal
cavity. Just as adhesions increase the likelihood of mechanical injury to bowel
during surgery, adhesions also are associated with increased likelihood of thermal
injury to bowel. Cassaro (Cassaro 2015)
discussed delayed manifestations of laparoscopic bowel surgery and noted that electrosurgery is used
extensively in laparoscopic surgery and can cause thermal injuries that are harder to
detect than mechanical injuries. It’s
important to recognize that thermal injuries may occur with use of monopolar
cautery even to tissues not in direct contact with the cautery tool. Cassaro
notes that electrosurgical
devices can cause thermal tissue damage through a number of
mechanisms, including:
·
unintended direct application of the
electrosurgical current to the tissues
·
transmission through another conducive
instrument, or coupling
·
discharge through faulty insulation
·
capacitive coupling, a phenomenon that occurs
when the surrounding charge that is associated with the use of all the
monopolar active electrodes is not allowed to flow back through the body
tissues to the passive electrode and builds up in a metal part of the instrument
that may then transfer this energy into the tissue and damage it
·
antenna coupling, which occurs when the active
electrode acts as an active transmitting antenna and emits energy, which is
captured without direct contact by an inactive wire in close proximity that
functions as an electrically inactive receiving antenna
He notes that, of these, all but the inadvertent direct application of thermal energy involve coupling and energy
discharge that are
likely to occur outside the operator’s limited field of view afforded by the
laparoscope. Alkatout et al. (Alkatout
2012) noted that most electrothermal injuries to the
bowel (approximately75%) are unrecognized at the time of occurrence.
Moorthy (Moorthy
2015) emphasizes that laparoscopic instruments should be regularly checked
to ensure that there is no damage to the insulation and that surgeons using
energy devices for the first time should be trained in their use. All these are
in addition to the issues associated with training and credentialing in
laparoscopic surgery.
See also our July
28, 2020 Patient Safety Tip of the Week “Electrosurgical Safety” for a good discussion of how thermal
injuries may be related to electrosurgical instruments.
The delay in development of symptoms following thermal injury to viscera is
typical. The initial thermal injury does not fully penetrate the wall of the
viscus (a “partial thickness” injury) but subsequently tissue necrosis occurs,
leading to perforation of the hollow viscus and leakage of contents into a body
cavity.
We’ve seen a trend
toward more robotic procedures, not only in gynecological surgery but in
urological and general abdominal surgery as well. Looking at thermal
injuries during surgery, Hodges found that injuries were to viscera in 44.4% of
robotic cases, compared to 1.7% in open surgical cases and 8.1% in laparoscopic
cases (Hodges 2023).
The overall incidence of thermal injury to viscera is unknown but these
statistics are bothersome and indicate the need for careful vigilance following
robotic procedures.
To summarize, thermal injury to viscera are
important for two reasons:
1.
They are often unrecognized during the surgery
2.
They typically present after a delay of several days
While careful technique and careful attention to tools used
during surgery are important, it’s most important that appearance of new
symptoms several days following surgery should merit prompt consideration of
the possibility of thermal visceral injury.
Our prior columns on
iatrogenic burns:
·
March 2009 “Risk
of Burns during MRI Scans from Transdermal Drug Patches”
·
June 1, 2010 “Iatrogenic
Burns”
·
October 5, 2010 “More
Iatrogenic Burns”
·
December
23, 2014 “Iatrogenic Burns in the News Again”
·
March
2015 “Another Source of Iatrogenic Burns”
·
September
5, 2017 “Another
Iatrogenic Burn”
·
June 5,
2018 “Pennsylvania
Patient Safety Authority on Iatrogenic Burns”
·
July 28,
2020 “Electrosurgical Safety”
·
January
2021 “New MRI Risk: Face Masks”
·
May 3,
2022 “Iatrogenic Burns Again”
·
December
6, 2022 “Rare Risk – Defibrillator
Fires”
·
April 25, 2023 “Joint Commission: Beware
Light Source Burns”
References:
Brotherton J, Chang F. Delayed Thermal Injury to the Ureter
during Total Laparoscopic Hysterectomy Using Ultrasonic Energy Source: A Case
Report. Journal of Minimally Invasive Gynecology 2008; 15(6) Supplement: 103S-104S
November 2008
https://www.jmig.org/article/S1553-4650(08)00777-2/fulltext
Oh BR, Kwon DD, Park KS, et al. Late Presentation of
Ureteral Injury After Laparoscopic Surgery. Obstetrics & Gynecology 2000;
95(3): 337-339
Cassaro S. Delayed Manifestations of Laparoscopic Bowel
Injury. The American Surgeon 2015; 81(5): 478-482
https://journals.sagepub.com/doi/10.1177/000313481508100529
Alkatout, I., Schollmeyer, T., Hawaldar, N. A., Sharma, N., & Mettler, L. (2012).
Principles and safety measures of electrosurgery in laparoscopy. JSLS : Journal of the Society of Laparoendoscopic
Surgeons 2012; 16(1): 130-139
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3407433/pdf/jls130.pdf
Moorthy K. Bowel Injury After Laparoscopic Surgery. AHRQ
PSNet WebM&M: Case Studies 2015; January 1, 2015
https://psnet.ahrq.gov/web-mm/bowel-injury-after-laparoscopic-surgery
Hodges MM. Thermal injuries during robotic surgery. YouTube
video of a talk at the Robotics/Advanced Technologies Abstracts session during
the 2020 SAGES Virtual Meeting.
https://www.youtube.com/watch?v=-cO_VrudHgw
Print “PDF version”
http://www.patientsafetysolutions.com/