“Minimal Access Surgery” began in animal laboratories and was later studied in selected academic centers where it was imported to community hospitalsonly when its benefits and safety were established. Objectives: To conduct a detailed review of Complications of laparoscopic surgery with emphasis on those related to entry into the abdominal cavityand bile duct surgery given their high frequency and lethality. Subject and methods: A detailed search ofliterature publishedin Spanish and English was carried out through PubMed/MEDLINE, Cochrane's registry of systematic reviewsand randomized controlled studies, using key words such as “laparoscopic entry”, “trocars injury”, “laparoscopy”. complications”, “laparoscopic injury” and “opticaltrocars”. Meta-analyses, randomized clinical studies, clinicalguidelines, review articles and case series were mainly selected.Conclusions: Laparoscopy is a relatively safe procedure, however, great care must be taken during access to the abdominal cavity because the majority of complications occur during entry

“Minimal Access Surgery” began in animal laboratories and was later studied in selected academic centers where it was imported to communityhospitals only when its benefitsand safety were established. Low complication rates were reportedby centers specialized in laparoscopic surgery,mostly academic centers.These centers were able to reduce complication rates to a minimum by developing the skills necessary for these surgeries. Unfortunately, many inexperienced surgeons developed these techniques without sufficient training and are responsible for the majorityof complications obtainedduring laparoscopic surgery.1

The development of Laparoscopic Cholecystectomy (LC) was not designed to improve the safety of the procedure, but rather to reducethe discomfort associated with the surgicalincision.

Doctors who have performed fewer than 100 such procedures have reported a complication rate of 14.7 per 1,000 patients. In contrast, expert surgeons reported having a complication rate of only 3.8 complications per 1000 procedures. The Southern Surgeons' Club reported that the survey or incidence of bile duct injuries was 2.2% when the surgeon had performed fewer than 13 procedures. As surgeonsgained experience, the incidence of bile duct injuries eventually decreased to 0.1%(2,3).

Objetives.

Carry out a detailed review of the Complications of laparoscopic surgery with emphasis on those related to entry into the abdominal cavity and bile duct surgery given their high frequency and lethality.

A detailed search of literature published in Spanish and English was carriedout through PubMed/MEDLINE, Cochrane's registry of systematic reviews and randomized controlled studies, using key words such as “laparoscopic entry”, “trocars injury”, “laparoscopy complications”, “ laparoscopic injury” and “optical trocars”. Meta- analyses, randomized clinical studies, clinical guidelines, review articles and case series were mainlyselected.

Development:

The use of laparoscopy to perform surgical procedures is increasing as it provides greater benefits, when compared to laparotomy, in terms of faster recovery, less postoperative pain,and shorter hospitalstay. However, since it is an invasive procedure, there is a risk of complications. These are dividedinto Intraoperative and Postoperative, but we are going to refer to Intraoperative, which in turn can be divided into 2 large groups:4

A – General Complications of Laparoscopic Procedures: 1- Related to the Introduction of Needles, Trocars and Insufflation 2- Typical of Pneumoperitoneum

3- Related to the introduction of laparoscopic surgical materials and manipulation of instruments.

B – Specific complications of each technique: (Biliary Surgery)

General Complications of Laparoscopic Procedures:

1. - Related to the Introduction of Needles, Trocarsand Insufflation

It is with the introduction of the Veress needle to create the pneumoperitoneum that any laparoscopic procedure begins. The impossibility of creatingthis adequately makes it impossible to place trocarscorrectly and will cause the surgery to fail.

Veress Needleand Trocars

Despite the advantages offered by the protection system of this needle duringits introduction, differentinjuries can occur, such as:

• Injury to the Abdominal Wall Vessels:

This complication is relatively frequent, it occurs mainly with the introduction of trocars and especially with those that have sharp edges (they have the advantage of requiring less pressure for their introduction into the abdominalcavity) than with those with a conical tip, less causing this complication. The solution to this is usually the compression of the wall, either directly with the sheath, or with the introduction of the sheath fixing sleeve that has a larger diameter and if it is not controlled, smallenlargements of the wound corresponding to the point of bleeding until they are located and hemostasis is achieved.

To avoid this, it is advisable to transilluminate the wall to visualize the largercaliber vessels in order to avoid injury.

• Large Vessel Injury:

This is usually due to injuries to the abdominal aortic bifurcation or the inferior vena cava, producing a large retroperitoneal hematoma that requires urgent laparotomy. The incidence of this complication is fortunately low, amounting to 0.05% in large multicenter series, but frequently fatal, which is why the introduction of the needle and the first trocar must be done with great care and with gentle maneuvers. If an injury occurred, depending on its magnitude, a laparotomy must be performed, checking for the existence of a vascular wound on the posterior face of the vessel at the level of the previouswound, and suturing it if necessary(5,6).

• Hollow VisceraInjury:

This can be in: Stomach, Small Intestine or Colon. It can occur more frequently when there is a previous abdominal surgery,which implies the possible existence of adhesions of the digestive tract to the anterior wall, which recommends puncture with the Veress needleaway from the laparotomy scar, in an upper quadrant,normally the left another method of avoiding this is by placing a Hasson trocar under direct vision (open Pneumoperitoneum). This injury can go unnoticed, which increases its severity as it is diagnosed late.

• Solid VisceraInjury:

It is infrequent, it is discovered once the optic is insertedand it is not usuallyserious; it is usually superficial punctures of the liver, whichspontaneously stop bleeding.

• Hernias in the trocarorifices:

Infrequent complication in holes of 5 and 10 mm in a lateralsituation, but very common in holes > 10 mm, especially in the midline and in the region of the lower abdomen, although it can appear in the upper abdomen if the incisionfor extraction is extended. of the surgical specimen, so suturing the aponeurosis of the midline trocars is always recommended. It is also important to take into account when removing the 10 mm trocar, especially the one in the umbilical region, since it cannot be removed suddenly because the CO2 must first be emptied from the cavity otherwise evisceration occurs due to the pressure. positive intra-abdominal thatforces the greater omentum, small intestine, out of the abdominal cavityand may go unnoticed at the end of the surgery(7,8,9).

An example of all of the above is that,in 2001, Bhoyruland collaborators analyzed 629 injuries caused by trocars, reportedto the Food and Drug Administration (FDA) between 1993 and 1996. 32 deaths were reported,of which 26 resulted from injury. vascularand 6 intestinal injuries, disposable trocars were used in 28 deaths, 3 by optical vision and 1 by reusable trocars, 408 injuries were vascular injuries and 182 were visceral injuries, 30 wall hematomas occurred and the other patients were not analyzed. These authors concludethat disposable trocarsand direct entry do not reduce visceralcomplications, and an unrecognized intestinal injury can be fatal(10,,11,12).

Insufflation

- Gas insufflation into the abdominal wall, mesentery, omentumor retroperitoneum:

Insufflation of CO2 into the omentum,mesentery or retroperitoneum produces emphysema that does not have great repercussions and disappears quickly,but the possibility of a vascular or visceral injury below this must be ruled out. These emphysemas often make the operating field difficult since they reduce the visual fieldand modify anatomical structures. (13)

If this insufflation occurs in the abdominal wall, it causes subcutaneous emphysema, which, although it has no clinical significance, can make it difficult to achieve pneumoperitoneum. It is evidencedby an asymmetrical abdominal distention of the abdominal wall, the presence of subcutaneous emphysema due to crepitusin the abdomen and high pressures markedby the insufflator and which warn us of incorrect placement of the needle.(14,15) In obese patients Gas insufflation may occur in the preperitoneal space that simulates a pneumoperitoneum since it can hold 3 to 4 liters in the preperitoneal space that occurs even with symmetrical abdominaldistention, but it is quicklyrecognized by high pressuresmaintained in the laparoinsufflator, as well as the absence of negative pressure. Therefore, it is important to always perform negative pressure tests of the abdominal cavity,injection of air or liquidinto the abdominal cavity with subsequent aspiration, and laparoinsufflator values below 8 mmHg. This is often detected when introducing the optic and observing that it is not in the abdominal cavity, making it necessary to communicate this space with the intra-abdominal space.(16,17,18)

1. - Typical of Pneumoperitoneum:

• Gas Embolism:

Produced by the sustained insufflation of CO2 pressures directly into a large-caliber venous vessel, it is a serious complication that requires rapid decompression of the abdominal cavity followed by cardiorespiratory recoverymaneuvers, which is why it is recommended not to use flows at the establishment of pneumoperitoneum greaterthan 1 or 1.5 litersper minute. (19,20)

It is recognized by the appearance of profuse sweating, sustained arterial hypotension, jugular engorgement, tachycardia, cardiac arrhythmias and distal cyanosis, as well as the recording of arterial O2 desaturation and hypercapnia raise the suspicionof this complication.

• Pain in the shoulders:

It seems to be related to the irritation of the diaphragms by CO2 and the rupture of its myofibrils. So an inflation pressure of 1 – 1.5 liters/min. prevents sudden distension of the diaphragm. This pain is easily combatable with analgesics and disappears in the first 48 hours after surgery.

- Iatrogenic Pneumothorax:

Its mechanism of appearance is not clear but barotrauma is invoked due to the sudden insufflation of the pneumoperitoneum, as well as possiblecongenital diaphragmatic defectsthat establish a pleuropulmonary communication that makes its establishment possible by increasing intra-abdominal gas pressures. Generally, this is resolved in the same surgical procedure, being very complicated if a hypertensive pneumothorax occurs where there is an increase in intrapulmonary pressures and O2 desaturation that is resolvedwith a Pleurostomy.

- Pneumomediastinum:

This generally occurs in esophageal hiatus surgeries when the abdominal cavity comes into contact with the lowermediastinum, so it is recommended to work with pressures < 12>

-Respiratory problems:

The hypercapnia that occurs during laparoscopic surgery is due to the sum of two factors: the increase in dead space (well-ventilated but poorly perfusedalveoli) and the absorption of CO2 by pneumoperitoneum. The measurement of expired CO2 (ETCO2) will be a good non-invasive control method; on the other hand, O2 saturation does not seem to be altered by pneumoperitoneum, but peak pressure (maximum pressure produced in the airway at each time) is elevated.ventilatory cycle, also producing a discrete metabolic acidosis, which becomes more evident the greater the hemodynamic impact. (21,22,23)

- Hemodynamic Repercussions:

At the beginning of insufflation, there is an increase in Central Venous Pressure (CVP), mean arterial pressure and cardiac output, but once the mean working pressure(12-14 mmHg) is established, it is higher than that of the venacava, which decreases CVP as well as cardiac output. Hypoxia, hypercapnia and decreased cardiac output may be the most important factors in the development of cardiac rhythm disorders.

3- Related to the introduction of laparoscopic surgical materials and manipulation of instruments:

The use of instruments inside the abdominal cavity must always be carried out under optical vision, to avoid injuries to the different abdominal organs, so we will follow their entire journey from their entry into the cavity. The design of this type of instruments such as scissors,aspiration cannulas and forceps are long, so perforation can occur at any level if these instruments are not enteredunder endoscopic vision. Injuries caused by incorrect use or uncontrolled mobilization of surgical instruments can go unnoticed, increasing their severity.(24,25,26)

Electrocoagulation deservesa separate comment,which is used with the dissector, scissors or hemostasis forceps. Its improper use can cause thermal injuries in unwanted places (diaphragm, digestive tract,bile duct, etc.). (26)

The high intensity of the light produced by the xenon source is capable of providing burns if the contact between the tip of the endoscope and the tissue or organ is prolonged. Inadvertent burns at the gastrointestinal level can cause perforation peritonitis, which generally appears on the 4th day. postoperative period, which is why the laparoscope must always be removed inside the trocar in the event of loss of pneumoperitoneum. (27)

Specific complications of each technique: (BiliarySurgery)

The risk of bile duct injury during laparoscopic cholecystectomy has increased due to the position and exposure of the anatomical structures of the extrahepatic bile ducts.

"Post-surgical or Iatrogenic Bile Duct Injury" is defined as any change secondary to surgery that causes bile leak from the biliary tree before the duodenal papilla, difficulty or impossibility of the passage of bile to the duodenum, or combinations of these. Vascularlesions of the biliary tree are also included,and can be of the hepatic, common,right or left arteries, as well as the portalvein.(28)

The annual incidenceof bile duct injuries increased from about 0.2%in the open cholecystectomy era to approximately 0.5% after laparoscopic cholecystectomy became widely available. (29)

Imaging is vital for initial diagnosis, evaluation of the extent of the injury, and planning prior to the surgical procedure. The use of percutaneous cholangiography, endoscopic retrograde cholangiopancreatography and magnetic resonancecholangioresonance allows establishing the site of the lesion. For the diagnosis of bile leaks and post-surgical biliary strictures, percutaneous cholangiography is considered the reference technique.

Bismuth Classification:

In 1982, Bismuth proposed a classification for Benign Primary Bile Duct Stenosis that is based on the anatomical pattern of the lesion. They are classified into five gradesaccording to the relationship they acquire with the confluence of the right and left hepatic ducts, not only defining postoperative strictures specifically, but also allowing comparisons of different therapeutic modalities with respect to the extent of the affectedbile duct. .

In turn, benign biliarystrictures are subdivided according to the degree of suprastenotic dilation.

Type I: Lesion > 2 cm from the confluences of the hepaticducts (18

– 36%)

Type II: Lesion < 2 cm from the confluences of the hepaticducts (27

– 38%)

Type III: Lesion that coincides with the confluence of the hepaticducts (20 – 33%)

Type IV: Destruction of the confluence, separated right and lefthepatic duct (14-16%)

Type V: Involvement only of the right sectoralbranch or in the commonbile duct (0-7%)

Strasberg classification:

This in turn definesLaparoscopic Injuries of the portalbile duct, which can be applied in the management of said injuries:

A - Leakage from the stump of the cystic duct or leakagefrom a canaliculus in the liver bed.

B - Occlusion of a part of the biliary tree, almost invariably an aberrant right hepatic duct.

C - Transection without ligation of the aberrantright hepatic duct. D - Lateral damage to a major hepaticduct.

E -Subdivided by Bismuthclassification into E1-E5.

Complications of cholecystectomy:

The female sex is the one that has presented the most iatrogenic lesionsof BPV since it is the one that undergoes the most surgeryfor benign diseasesof the Gallbladder, this corresponds to what is reported by the world literature which indicates that the female sex is the most affected by gallbladder lithiasis as well as secondary stones in the common bile duct, which is why they are at greater risk of suffering from acute biliopancreatic conditions and, therefore, having this procedure performed(30).

• Injury to the main bile duct.

Injuries to the main bile duct have been the greatest concern since the emergence of the laparoscopic era. It is undoubtedly the most seriouscomplication that can occur when performing a cholecystectomy and the mechanism by which it occurs can be diverse:

1. Clipping and total or partial section of the commonbile duct: This complication occurs by excessively pulling on the cystic duct, angulating the common bile duct and placing the clip so that the main bile duct is cut instead of the cystic duct. Sometimes the clip affects the cysticocholedochal junction, partially occluding the common bile duct lumen. Other times, the cystic duct is confused with the distal common bile duct in the dissection, clipping and sectioning it in its entirety.
2. Hemorrhage in Calot's triangle.An uncontrolled attemptat hemostasis, without good visualization of the bleeding vessel and with the placement of countless clips, can result in total or partial occlusionof the bile duct.
3. Injury with electrocautery. Areas of necrosis or retractions may occur that subsequently lead to a stenosis of the bile duct.

• Hemorrhage:

The two most frequent causes of hemorrhage during laparoscopic cholecystectomy are: injury to the cystic artery and bleeding from the gallbladder bed. These are usually overcome when the surgeon has experience.

Hemorrhage from the gallbladder bed can be very annoying, with the risk and difficulty of hemostasis being greater in cirrhotic patients, so we recommend sticking as much as possible to the wall of the gallbladder even at the cost of producing small gallbladder perforations that have no greater importance, and that only require a correct washingof the subhepatic and subphrenic spaces.

In case of Cystic Artery Injury, hemostasis must be performed with a clamp temporarily, so that it allows us to aspirate the blood and perfectvisualization of the vessel that we are going to clip.

When hemorrhage occurs in the immediatepostoperative period, the indication for surgical revisionis imposed, startingwith the laparoscopic route that allows us to wash-aspirate clots and blood from the abdominal cavity. Once it is confirmed that there is no active bleeding, a penrouse drainage tube is placed in the Winslow Hiatus.

• Forgotten Calculations:

Relatively frequently, stones fall into the peritoneal cavity, this can be complicated if the stones are not easily visualized. For this reason, on some occasions stones remain in the abdominal cavity that only exceptionally cause problems in the form of an abscess,

which is why these must beremoved either with the aspirator if they are small in size or with tweezersthrough the 10 mm pods.

Coleperitoneum:

The treatment is laparoscopic reintervention, with cavity washing, new transcystic cholangiograms and after verifying the existence of a leak, the subhepatic space is drained with a silicone tube, leaving the probe used for the cholangiographies and extracting it through another contracture for the subsequent checking the bile duct.

Complications in choledocholithiasis surgery:

Laparoscopic management of choledocholithiasis, as in laparotomic surgery, involves correct exposure of the main bile duct and this is where the most frequent intraoperative problems can occur.

- Hemorrhage:

It occurs as a consequence of injury to the pericholedochal vessels, and althoughit is not usually important, it does hinder correct visualization of the common bile duct, which requiresits hemostasis with a suture, or very carefully with the use of electrocautery. so as not to produce thermalinjuries that causesubsequent stenosis.

Bilirhagia:

Bile loss through subhepatic drainage does not usually cause problems. It is common for patientsundergoing primary choledochorrhaphy to have a flow of 300-400 ml of bile through the subhepatic drainage duringthe first 24-48hours, reducing drastically in the followinghours.

- Residual Lithiasis:

This is undoubtedly the complication that most affects the patient, since it will give rise to a new procedure that will have to be undergone, whether surgical, endoscopic or radiological depending on the time of diagnosisand whether or not the patient is a carrierof the disease. a Kehr T-tube.

The complications associated with ERCP and EE are hemorrhage, pancreatitis, perforation and infection. ERCP, more than any other endoscopic procedure, has risk factors for complications depending on the patient,the procedure and the endoscopist (6).

Preventive Measures to avoid Iatrogenic Bile Duct Injury:

(LIVB)

There are multiple techniques for the prevention of LIVB: use of a 30-degree chamber, avoidance of the use of thermocoagulation near the main VB, meticulous dissection, and conversion to open surgerywhen the anatomy is uncertain. In the CL, the reference point is the RouviereGroove. Since the main causeof LIVB is misidentification of the main VB or an aberrant duct as CC, the surgeon must use an artery and CC identification method. Among the methods used we highlight:

Tristructure Method: We must identify during LC: CC, common hepatic duct andcommon bile duct.

Fischer method:It consists of separating the gallbladder completely from the gallbladder bed from the bottom towards the infundibulum as in open surgery, until it hangs from the artery and the CC. This is especially difficult in the case of intrahepatic or highly inflamed vesicles. 3. Infundibular Technique: It consists of identifying the CC when it joins the gallbladder infundibulum. It is the techniquemost currently used in most centers. It has the 

disadvantage of not preventing LIVB in patients with occult cystic duct syndrome.For this reason, differentgroups systematically recommend the use of intraoperative cholangiography (IOC) with this type of technique.

Strasberg's Critical View Technique: It is the preferred method by most surgeons, it consists of dissecting and releasing theCalot triangle until exposing the artery, the cystic duct (CC) and exposingthe base of the gallbladder. observing the liver without any structure that interferes with the visualization of this organ. Once this view is achieved, these structures can only correspond to the duct and the cystic artery. (31)

VCS is a method described in 1992 and published by Dr. Steven M. Strasberg. Later in 2013, Stanford and Strasberg proposedphotographic documentation of VCS with the aim of increasing safety in laparoscopic cholecystectomies. This photodocumentation consists of qualifying the anterior and posterior vision of the SVC using an established score, using the term double view, constituting an excellent method for preventing bile duct injury and perhaps the next step. With greaterimportance in the lists presentedby the 2018 Tokyo Guidelines for the surgicalmanagement of Acute Cholecystitis, the partial diffusion that SVC has had in surgical practice may be one of the main limitations in the development of the so-called culture of safe cholecystectomy. In 2017, Dr. Strasberg noted that he had detected that after 20 years many surgeons have little understanding of the criteriarequired to achieveSVC, especially those who did not have training in implementing SVC in laparoscopic cholecystectomies during their residency, so who opt for simpler methodssuch as the Infundibular technique, which represent a greater risk of injury to the BiliaryTract. Other obstacles mentioned are that when SVC is carriedout, photographic documentation is generally not carried out with the qualification of the “ pair vision.” Cholangiography: Since the Argentine Pablo Mirizzi introduced the first intraoperative cholangiography in 1932 until today, its benefit in preventing LIVB is debated since IOC can help avoid LIVB for at least 3 reasons:

. Shows the diversity of the biliarytree and its abnormalities.

. Helps the surgeon identify patients at risk for LIVB due to abnormalanatomies.

. If LIVB has occurred,it allows for its identification and repair.

Intraoperative laparoscopic ultrasound: In a recent multicenter study, its advantages for the prevention of LIVB are highlighted, although it is a very expensive method and sometimes not available in all hospitals, which does not completely replace IOC but which opens a hopeful future. (32)