Hacking You… Tube – Part 1

A plumber is an adventurer who traces leaky pipes to their source.

Arthur Baer

Grey Turner once said that “these injuries can occur even in the hands of the most capable and experienced surgeon”.

Introduction

Iatrogenic bile duct injuries (IBDI) represent one of the most serious complications following cholecystectomy, they bring disastrous consequences in terms of morbidity and mortality.

Unfortunately, a 0% rate is still not achieved, according to the last published bibliography we still live with an incidence between 0.2-0.5%.

Would you catch a plane with that risk of crashing?

The introduction of laparoscopic cholecystectomy (LC) had a great impact on the severity of these injuries, as they are more complex (being higher in location, sometimes even intrahepatic) and with more associated vascular injuries (especially of the right hepatic artery) compared to open surgery.

For severe injuries, short-term morbidity rates of up to 40-50% and mortality rates of 2-4% have been reported.

Classifications

In terms of classifications, there is no ideal classification at present. The World Society of Emergency Surgery guidelines recommend the Strasberg classification, which is still the most widely used to describe bile duct injuries, and the ATOM classification, which represents the most recent and comprehensive classification.

The Strasberg classification (Figure 1) covers biliary injuries caused by LC. It is more complete and easier to understand than the other classifications. However, it only analyses IBDI, without taking vascular injuries into account. It is divided into five groups (A-E). A to D involves IBDI where there is no complete section of the bile duct and E where there is a complete section at different levels.

The ATOM classification (Figure 2) assesses the involvement of the bile duct (primary or secondary), the type of injury (occlusion or section), whether there is associated vascular injury, the time of detection (intraoperative, immediate, or delayed postoperative) and the mechanism of action (by thermo-coagulation or other). The main drawback is that it may be too complex and time-consuming to be used in routine clinical practice. The surgical sheet should contain as much detail as possible to maximize the amount of intraoperative detail to describe the bile duct injury.

Risk Factors

The main thing to take into account to avoid injuries of this type is to know the risk factors. There are several risk factors in which we find:

• Anatomical factors (most frequent cause)
• Nature of pathology: acute cholecystitis, cholelithiasis, Mirizzi’s syndrome…
• Technical-anatomical problems
• Other (e.g. obesity, advanced age, male sex)

Anatomical Factors

The main risk factor is misidentification of the biliary anatomy in 70-80 % of all IBDI. There are numerous anatomical variants of the biliary tract representing a possible cause of iatrogenic injury, e.g. the different variants of the cystic duct shown in Figure 3.

In addition, it is also important to take into account the anatomical variants in terms of vascularization since IBDI can be associated with vascular injuries (estimated at 12-39%). We know that the cystic artery comes from the right hepatic artery in 80-90% of cases, but we can find anatomical variants as shown in Figure 4.

Nature of the Pathology

Inflammation during acute cholecystitis around Calot’s triangle makes the tissue friable and difficult to grasp. Bile duct injuries in cholecystectomy for acute cholecystitis have been reported to be 3 times more frequent with an incidence of up to 0.77-5%.

When a scleroatrophic gallbladder is also associated, the technical difficulties are even greater. Dissection in such conditions favors bleeding, which increases the risk of biliary iatrogenesis (if the patient is asymptomatic, think seriously if you have to operate or not). Other situations such as acute pancreatitis, large gallstones, short cystic duct, Mirizzi’s syndrome, etc., may favor the development of IBDI.

Technical-Anatomical Problems

Within this group, we find:

• Excessive traction of the gallbladder’s fundus creating the tent effect
• Cholangiographic cannula injury
• Injury due to uncontrolled electrocoagulation
• Injury from poor visualization of the surgical field (e.g. hemorrhage)
• Incomplete cystic clipping

Prevention

There are multiple techniques for the prevention of bile duct injuries, summarized in Figure 5.

The “critical safety vision (CSV)” technique is considered the gold standard for safe cholecystectomy with the identification of biliary structures during dissection.

Three criteria are required to achieve SVC:

1. The hepatocystic triangle must be clear of fatty and fibrotic tissues; neither the common bile duct nor the hepatic duct must be exposed;
2. The lower third of the gallbladder must be separated from the hepatic bed to expose the cystic plaque;
3. Two and only two structures should be seen entering the gallbladder.

The CVS was not conceived as a way to perform laparoscopic cholecystectomy, but as a way to avoid biliary injury.

The literature has shown that when CVS is identified, the risk of iatrogenic intraoperative complications is minimized. Therefore, the routine use of CVS is recommended over other techniques. However, complete CVS is easily achieved in only 50% of cases. The most common incomplete component is the clearance of the lower third of the gallbladder from the liver bed. CVS cannot always be applied if the hepato-cystic angle is affected by advanced inflammation or contracting fibrosis due to preceding episodes of inflammation.

Remember not to “force” a CVS: if you cannot dissect the tissues, you should change the plan!

When CVS cannot be performed and the biliary anatomy cannot be clearly defined, alternative techniques such as the infundibular technique, the fundus first approach, or subtotal cholecystectomy (STC) are available.

One of the backup plans may be the infundibular technique. It consists in identifying the cystic duct by joining it to the gallbladder infundibulum. In these cases, some surgeons prefer to perform the infundibular approach to work close to the gallbladder infundibulum, reducing the risk of biliary injury. However, beware of the “hidden cystic duct” syndrome that presents a misleading appearance of a false infundibulum, leading the surgeon to identify the common bile duct as the cystic duct.

Nevertheless, this technique, which relies on seeing the widening of the cystic duct as it becomes the infundibulum, is especially prone to be misleading in acute inflammation as it can be mistaken for the junction of the cystic and common hepatic duct. This technique is unreliable and should not be used alone for anatomical identification of ducts. This is why different groups systematically recommend the use of intraoperative cholangiography in conjunction with this type of technique.

Last but not least, the STC (or “partial cholecystectomy”), which consists in opening the gallbladder, clears the entire content, eventually leaving the posterior wall of the gallbladder attached to the liver, and securing the cystic duct at its origin from within the gallbladder. It has been described as an easy and safe operation for “difficult gallbladders”. The indications for subtotal cholecystectomy are the same as for a conversion, particularly when a CVS is not achieved.

In addition to the CVS, several anatomical landmarks have been described that can be useful in performing a safe cholecystectomy, such as:

• Rouvière’s sulcus (don’t go below!)
• Cystic lymph node or Mascagni’s node (leave it in the patient, pass on the patient’s right side of it!)
• The B-SAFE method

The “B-SAFE” mnemonic method uses five anatomical landmarks to correctly place their cognitive map during dissection (Figure 6):

B – Bile duct
S – Rouvière’s sulcus
A – Hepatic artery
F – Umbilical fissure
E – Enteric/duodenum

With the correct identification of the different structures we can establish an imaginary line, above this line we will be in a much safer area for performing cholecystectomy.

Many authors admit that routine cholangiography largely avoids IBDI and contributes to earlier diagnosis/treatment, especially in the case of smaller injuries. This technique does not entirely eliminate the risk of IBDI, though. However, its routine use is currently not mandatory as it is not associated with a significant reduction in complication rates and IBDI during LC.

The use of intraoperative ultrasound is a sensitive method to visualize the anatomy of the extrahepatic bile duct but is not commonly used in clinical practice due to its learning curve and lack of current scientific evidence.

 Conversion to laparotomy is one of the most frequently used alternatives to avoid IBDI in difficult situations, as it provides better exposure, palpation, and direct sensation of the anatomical structures. Conversion to open surgery may be for patient safety if the surgeon cannot manage difficult LC; however, there is no evidence to support that conversion to open per se avoids or reduces the risk of IBDI. Another circumstance where conversion is appropriate is uncontrollable bleeding and rigid adhesions to the transverse colon or duodenum. Surgeons with advanced laparoscopic skills can resolve most of these problems without having to convert. More, always ask yourself: How many open cholecystectomies have I performed? Would I feel more comfortable operating a complex gallbladder in laparotomy? Think a couple of times more before conversion, if it is not in your daily hands… Maybe there is another way to solve the problem… Call for help to say one…

Near-infrared fluorescence cholangiography (NIRF-C) represents an intraoperative imaging technique that allows enhanced real-time visualization of the extrahepatic biliary tree by fluorescence. NIRF-C represents a useful method to identify CVS with the help of real-time fluorescence vision.

Several clinical trials conclude that NIRF-C is statistically superior to “standard” vision alone for visualizing extrahepatic biliary structures during laparoscopic cholecystectomy (using 0.05 mg/kg indocyanine green, 45 minutes before surgery in elective cases).

Furthermore, compared to other intraoperative imaging procedures, such as intraoperative cholangiography, NIF-C requires no incisions, requires much less time and only a small fraction of the cost, it is easier to learn and monitor, requires no radiation or expensive equipment, and, because it does not require radiation, can be repeated as many times as necessary. Indocyanine green is even considered safe for use during pregnancy. It can also be used in longer and more complicated surgical procedures, with peak visualization lasting 2 hours or more after intravenous injection, and since it is usually administered through a peripheral vein, it could be re-administered if necessary.

It is reasonable to expect that up to 90% of IBDI have been attributed to inadequate visualization of biliary structures (especially the common bile duct)… So, the ability of NIRF-C to improve such visualization could further reduce the risks of such injuries.

Although large-scale comparative trials are still needed, preliminary analyses suggest that the use of near-infrared fluorescent cholangiography with indocyanine green intraoperatively significantly decreases bile duct injury and conversion rates to open surgery relative to white light cholecystectomy alone.

The following list describes 10 ideas for safe cholecystectomy as described by Dr. Esteban Cugat, as he teaches the residents:

• Exists only 1 cystic duct
• There may be 2 cystic arteries
• The 3rd one is the hepatic artery
• Dissecting 4 tubular structures? Stop and replan!
• 5 minutes without hemorrhage control? Call for help or convert!
• 6 hours postoperatively, the patient should be fine
• More than 7 clips used? Stop and replan!
• 8 days post-op physical exploration and lab tests should be perfect
• cystic duct of more than 9 mm? It could be the main bile duct!
• 10 minutes without any progression? Stop, replan, call for help!

We think you may be already tired now, so let’s spare the clinical manifestation/diagnosis and treatment options for the next time!

See you all in a month… Namasté!

References

1. de’Angelis N, et al. 2020 WSES guidelines for the detection and management of bile duct injury during cholecystectomy. World J Emerg Surg 2021;16.
2. Fingerhut A, et al. ATOM, the all-inclusive, nominal EAES classification of bile duct injuries during cholecystectomy. Surg Endosc 2013;27:4608-19.
3. Schreudera AM, et al. Impact of iatrogenic bile duct injury. Dig Surg 2020;37:10-21.
4. Strasberg SM, et al. Avoidance of biliary injury during laparoscopic cholecystectomy. J Hepatobiliary Pancreat Surg 2002;9:543-7.
5. Moldovan C, et al. Clinical and surgical algorithm for managing iatrogenic bile duct injuries during laparoscopic cholecystectomy: a multicenter study. Experimental and Therapeutic Medicine 2021;22:1385.
6. Pesce A, et al. Iatrogenic bile duct injury: impact and management challenges. Clinical and Experimental Gastroenterology 2019;12:121-8.
7. Brunt LM, et al. Safe cholecystectomy multi-society practice guideline and state of the art consensus conference on prevention of bile duct injury during cholecystectomy. Ann Surg 2020;272:3-23.
8. Mascagni P, et al. Artificial intelligence for surgical safety: automatic assessment of the critical view of safety in laparoscopic cholecystectomy using deep learning. Ann Surg 2022;275:955-61.
9. Traverso LW, et al. Intraoperative cholangiography lowers the risk of bile duct injury during cholecystectomy. Surg Endosc 2006,20:1659-61.
10. López-López V, et al. Lesiones iatrogénicas de la vía biliar. Diploma de especialización en bases de la cirugía hepatobiliopancreática y trasplante. Módulo 3. Patología de las vías biliares.

How to Cite This Post

Galofré C, Marrano E, Bellio G. Hacking You… Tube – Part 1. Surgical Pizza. Published on July 30, 2023. Accessed on September 10, 2023. Available at [https://surgicalpizza.org/rescue/hacking-you-tube-part-1/].