Discussion of laparoscopic cholecystectomy is incomplete without a review of the anatomy of the gall bladder and the biliary tree.
Common Hepatic Duct

• The common hepatic duct is the length of biliary duct from the hepatic duct confluence to the cystic duct. The common hepatic duct makes up the left border of the tri- angle of Calot. The length of common hepatic duct varies from 1 to l0cm depending on the location of the junction with the cystic duct.5 where it then becomes the common bile duct.'

• The common hepatic duct can often be associated with accessory ducts. They are readily injured at cholecystectomy if they traverse the tri- angle of Calot. In more than half of the cases in which an accessory duct is found, it joins the common hepatic duct somewhere along its course. Less frequently, the accessory duct joins the cystic duct. In the rarest of instances. It may join a duct in the opposite lobe. The majority of aberrant ducts are on the right side.

Gallbladder

• The gallbladder is a pear-shaped, distensible appendage of the extrahepatic biliary system, usually holding 30 to 50 ml of bile. The gall bladder is attached to the liver by areolar connective tissue that contains multiple small lymphatics and veins.
• Rarely, one or more small accessory bile ducts pass through this tissue to enter the gallbladder directly (ducts of Luschka).6 In extremely unusual cases, major hepatic ducts might even drain directly into the gallbladder.
• This intimate relationship to the visceral surface of the liver easily permits direct spread of gallbladder inflammation, infection or neoplasia into the parenchyma of the liver. The transition between the neck and the cystic duct can be gradual or abrupt. The neck is quite short, usually 5 to 7mm.7
• Unusual morphologies of the gallbladder including septations or duplications or even agenesis may occasionally present during laparotomy or laparoscopy. A septated gallbladder is by definition a bilobar gallbladder with a single cystic duct but two fundi. Duplication of the gallbladder means the presence of two cystic ducts. A double cystic duct draining a unilocular gallbladder has once been described. More frequently encountered anomalies of the cystic duct and gallbladder are intrahepatic gallbladders and a gallbladder within the left lobe of the liver. 16

Cystic Duct

• The cystic duct is the route by which the gallbladder empties its bile. It connects the neck of the gallbladder to the common hepatic duct. In as many as 10% of cases, a portion of the right hepatic biliary system joins the cystic duct before its junction with the common hepatic duct. Generally, the cystic duct is about 4cm long. The length may vary from 0.5 to 8cm depending on the site of the gallbladder and the junction with the common hepatic duct. The circumference of the duct varies from 3 to 12mm.8
• As a general rule, the cystic duct joins the right aspect of the common hepatic duct. The cystic duct may (1) join the common hepatic duct at various angles; (2) be parallel to the right side of the common hepatic duct before entering it; (3) be dorsal to the common duct and enter its dorsal surface; (4) be dorsal to the common duct and enter it from the left side; (5) enter the right or left hepatic duct directly; or (6) join the common duct just before it enters the posteromedial wall of the duodenum. The mode of entrance of the cystic duct into the common hepatic duct may be angular, parallel, or spiral. The variable site of the union of the hepatic and cystic ducts determines the length of the common bile duct. If this union is low, that is, distal within the porta hepatis near the duodenum, the supraduodenal portion of the common bile duct is very short or even absent. If this is the case, the cystic and common hepatic ducts run parallel for a considerable length, causing difficulties during cholecystectomy. The cystic duct may also be very short or absent, in which case the gallbladder may appear to empty directly into the common hepatic duct.

• Calots triangle is the region bounded by the cystic duct, common (or right) hepatic duct, and inferior border of the liver. Bile duct injuries during cholecystectomy most frequently occur because of poor exposure of Calot's triangle, leading to confusion between the common hepatic or common bile duct and the cystic duct.

• The apex of the triangle contains the cystic artery, as well as the right branch of the hepatic artery, 95% of accessory right hepatic arteries, and 90% of accessory bile ducts. An anomalous hepatic artery arising from the superior mesenteric trunk (replaced right hepatic artery) usually courses superiorly in the groove posterolateral to the common bile duct. Therefore, it appears on the medial side of the apex of Calot's triangle, just behind the cystic duct where it is vulnerable to injury during cholecystectomy.
• Another landmark in this region that can be helpful in identifying the plane of the common bile duct and avoiding injuries during cholecystectomy is Rouviere's sulcus, identified by Rouviere in 1924 as a 2- to 5-cm sulcus lying anterior to the caudate lobe and running to the right of the liver hilum and usually containing the right portal triad.

Common bile duct

• The junction of the common hepatic duct with the cystic duct forms the common bile duct. The length of the common bile duct is variable, reported in adults as short as 1cm and as long as 17 cm, After cholecystectomy, the normal common bile duct may dilate to 10 to 12mm.
• Once the common bile duct has formed by the junction of the cystic and common hepatic ducts, it is designated as the supraduodenal segment of the common bile duct. Subsequently, it becomes the retroduodenal portion that in turn leads to the pancreatic and eventually the intraduodenal segments of the common bile duct.

Arterial Supply

• The hepatic artery supplies approximately 25% of the total blood flow to the liver; however, it provides up to 75% of the oxygenated blood and about 85% to 90% of the blood to the extrahepatic biliary system.
• Because of abundant collaterals, ligation of the hepatic artery proximal to the gastroduodenal artery fails to damage the liver.
• Ligation of the hepatic artery distal to the gastroduodenal artery occasionally produces hepatic necrosis Usually, however, this does not result in serious consequences because there are also rich extrinsic collaterals to the hepatic artery beyond the gastroduodenal artery. Ligation of the right or left hepatic artery individually predictably results in marked elevation of hepatic enzyme levels but often still without severe clinical manifestations,
• The gallbladder receives its blood supply from the cystic artery. The cystic artery usually originates from the right hepatic artery shortly after it passes beneath the common hepatic duct.
• The site of origin of the cystic artery varies greatly, however. The more common variations are from an aberrant right hepatic artery, left hepatic artery, more proximal hepatic artery, gastroduodenal; or even another branch of the celiac artery. In about 10% of cases, a double cystic artery is present. In most cases, the cystic artery branches near the neck of the gallbladder.
• The blood supply of the common bile duct classically arises from the cystic artery or the posterior superior- pancreaticoduodenal artery.

                       
Venous drainage

• There is no constant single venous trunk of the gall bladder. Venous return from the gall bladder occurs in multiple directions, via multiple small vessels running directly into the liver bed or towards the common duct.
• The ventral surface of the common duct is marked by a constant ascending vein that can become a hindrance if bleeding from this vessel cannot be controlled during duct surgery.

 Lymphatics

• The lymphatic drainage of the gallbladder is into cystic duct nodes near the superior aspect of the cystic duct or directly into the hepatic parenchyma.
• Numerous lymphatics traverse the connective tissue between the gall- bladder and its bed in the liver. This lymphatic (and adjacent venous) drainage accounts for the high rate of local invasion seen with gallbladder malignancies.

• The lymphatic drainage from the common bile duct courses superiorly and inferiorly into nodes that lie along the course of the duct and finally into a group of 6 to 10 nodes in the porta hepatis. Some lymphatic drainage from the common duct reaches the deep pancreatic group of nodes, situated near the origin of the superior mesenteric artery, but usually the drainage reaches into the deep celiac nodal group.

Anatomic Changes from Gallbladder and Biliary Pathology

Investigations

• Apart from routine blood tests, LFT, PT are must.
• Ultrasonography
• CECT / MRCP in case picture is not clear with ultra sound .
• HIDA SCAN or Cholescintigraphy

A cholescintigraphy or Hepatobiliary Imino-Diacetic Acid scan, (HIDA scan) is a nuclear imaging procedure to evaluate the health and function of the gallbladder. A radioactive tracer, usually technetium-99m, is injected through any accessible vein, then allowed to circulate to the liver, where it is excreted into the biliary system and stored by the gallbladder and biliary system.[1]

Operative Technique

• Laparoscopic cholecystectomy:

• Dissection of gall bladder
• Ligation of cystic duct
• Proximal clipping of cystic duct

1. dissection of gall bladder from fossa
2. final removal of gall bladder
3. insertion of gall bladder in sterile plastic bag

1. Gall bladder with stones
2.  Gall stones
3. Gall stones

• Choledocholithotomy:

• CBD exploration becomes essential when it is dilated or there is dilatation of intra hepatic biliary radicles i.e. there is obstruction to the flow of bile through the common duct due to stones in the CBD or stricture of CBD or neoplasm of the biliary tree.
• About 10% of all patients undergoing cholecystectomy for symptomatic gallstones will also have choledocholithiasis. Patients with obvious clinical jaundice or cholangitis, a dilated CBD, or stones visualized in the CBD on preoperative ultrasonography are likely to have choledocholithiasis (risk > 50%).
• Patients who have a history of jaundice or pancreatitis, moderately elevated preoperative levels of alkaline phosphatase or bilirubin, or ultrasonographic evidence of multiple small gallstones are somewhat less likely to have choledocholithiasis (risk, 10% to 50%).
•  Patients with large gallstones, no history of jaundice or pancreatitis, and normal liver function are unlikely to have choledocholithiasis (risk < 5%).

• Many methods are available for the exploration of CBD like open choledocholithotomy, ERCP (endoscopic retrograde cholangiole pancreatography), laparoscopic CBD exploration.

• Laparoscopic CBD exploration:

• Large stones (> 1 cm), as well as most stones in the common hepatic ducts, are not retrievable with the techniques described above. Ductal clearance can be achieved via choledochotomy if the duct is dilated and the surgeon is sufficiently experienced. (46, 47)
• The anterior wall of the CBD is bluntly dissected for a distance of 1 to 2 cm. When small vessels are encountered, it is preferable to apply pressure and wait for hemostasis rather than use the electrocautery in this area. Adrenaline-soaked gauzes placed' through the 12 mm umbilical port are very effective for this purpose. Two stay sutures are placed in the CBD.
• An additional 5 mm trocar is placed in the right lower quadrant for insertion of an additional needle driver. A small longitudinal choledochotomy (a few millimeters longer than the circumference of the largest stone) is made with curved microscissors on the anterior aspect of the duct while the stay sutures are elevated.
•  A choledochoscope is then inserted and warm saline irrigation initiated. In most cases, baskets should suffice for stone retrieval; however, lithotriptor probes and lasers are available for use through the working channel of the choledochoscope. The choice of approach depends on' availability and individual surgical experience.
• Subsequently, a 12 or 14 French latex T tube is fashioned with short limbs, placed entirely intraperitoneally to prevent C02 from escaping, and positioned in the CBD. The choledochotomy is then closed with fine interrupted absorbable sutures
• The first suture is placed right next to the T tube, securing it distally, and the second is placed at the most proximal end of the choledochotomy; lifting these two sutures facilitates placement of additional sutures. Intracorporeal knots are preferred to avoid sawing of the delicate tissues. The end of the T tube is then pulled out through a trocar, and cholangiography is performed after completion of the procedure.

• Stones in the common bile duct
• Laparoscopic common bile duct exploration

• Open Choledocholihotomy:
  The same procedure clan be done, with open method when surgeon is uncomfortable doing laparoscopic CBD exploration.

• Endoscopic retrograde cholangiopancreatography (ERCP):

                                    
Complications:
1. Anaesthesia related problems:
Among the potential complications of general anesthetics are hypoventilation, esophageal intubations; gastroesophageal reflux, bronchospasm, hypotension, narcotic overdose, cardiac arrhythmias and cardiac arrest. CO as an insufflation, medium causes a decrease in parameters like p02, 02 saturation, tidal volume and minute ventilation and an increase in respiratory rate. Elevation of diaphragm causes basilar atelectasis, right to left shunt and hence ventilation per-fusion mismatches and decreased respiratory compliance.

2. Pneumoperitoneum related problems:

• Carbon dioxide embolism:
• C02 is the most widely used peritoneal distension medium. Most C02 micro emboli are absorbed, usually by the splanchnic vascular system, quickly and without incident. However sever cardio respiratory compromise may result if large amount of C02 gains access to the central venous circulation, such as with inadvertent intravascular placement of an insufflation needle.
• Diagnosis confirmed by sudden, unexplained hypotension, cardiac arrhythmia cyanosis, development of a classic 'mill wheel murmur', increased tidal C02, findings of pulmonary edema and pulmonary hypertension resulting in right side heart failure.
• Treatment includes immediate intraperitoneal gas evacuation, 100°;0 02 administration, vasopressor support and hyperventilation to aid elimination of C02. Durant's position (left lateral position) displaces gas from right ventricular outflow pulmonary tract to right ventricle, thus relieving the functional obstruction.
• Cardiovascular complications:

Cardiac arrhythmias can develop commonly due to hypercarbia and resulting acidemia.
Operating at pressures less than 12 mm of Hg can prevent these. Pneumothorax is also a known complication of positive pressure ventilation due to high peak airway pressure.

• Gastric reflux:
  Gastric regurgitation and aspiration are problems increased due to Trendelenburgh position and also increased intra-abdominal pressure These can be avoided by fasting at least 8 hours prior to surgery and for introduction of a nasogastric tube to empty the stomach.

3. Veress needle and trocar injuries.
GI. Tract injury:

• Needle entry into abdominal GI. tract organs may occur and commonly is in the stomach due to gastric distention or when adhesion binds the stomach to the abdominal wall. The injury is often created by the primary trocar because of its blind insertion.
• Recognizing gastric entry by the insufflation needle may follow identification of signs of extraperitoneal entry, such as increased filling pressure, asymmetric distention of the abdomen, or the aspiration of gastric particulate through the lumen of the needle. Colonic injury is manifested by feculent odour. Such injuries are Common in patients with previous surgeries where the bowel is adherent to the anterior abdominal wall. Risk of injury can be significantly reduced by liberal use of oral or nasogastric decompression. Consequently, preoperative mechanical bowel preparation should be used in high-risk cases.
• Also use of left upper quadrant for insertion of the first trocar can be used. This approach allows direct insulation of abdominal wall under the umbilicus or other planned site of insertion and may facilitate dissection of underlying adhesion.
•   The management depends on the nature of injury. Insufflation needle punctures that have not caused a defect significantly larger than their diameter can be handled expectantly. Large defects should be repaired by laparoscopic or laparotomy based approach. Extensive lesions may require resection and reanastomosis
• Urologic injury.

• Injury to the bladder may occur during insertion of Veress needle or trocar. These are more often when bladder is adherent to the anterior abdominal wall after pelvic surgery. The diagnosis is easy if the surgeon recognizes entry into the hollow viscous or urine in the operative field. Hematuria suggests urinary tract injury and pneumaturia is diagnostic of visceral entry. The existence of bladder injury can be confirmed by instilling methelene blue in an indwelling catheter. The injury can be easily prevented by routine preoperative bladder drainage and thorough knowledge of anatomy.
• Small caliber (l-2mm) injuries heal spontaneously by prolonged catheterization (1 -2wks). Significant injury (above 2cm) can be repaired laparoscopically or open technique by either single or double layer with absorbable sutures. For injuries involving the trigone, open repair is preferred. Similarly ureteric injuries can be treated by insertion of a ureteric stem kept for I5-20 days.

c) Vessel injury.

Great vessel injury: 

• Injury to the great vessel like aorta, common iliac vessels, internal and external iliac vessels can occur during insertion of veress needle or trocar. Often the manifestation is egress of blood through the cannula and sudden hypotension. Frequently bleeding is contained in the retroperitoneal space, which delays diagnosis. The management consists of immediate laparotomy and arrangement of blood for transfusion.

Abdominal wall vessel injury;

• Commonest vessel injured is the superficial inferior epigastric vessels as they branch from the femoral artery and course cephalad, The problem is recognized by observation of blood dripping along the cannula or out through the incision. These injuries can be managed by application of pressure by change of position of cannula, pressure by Foleys catheter balloon hitched to the abdominal wall or placing a horizontal mattress suture to be removed after 48hrs.

4) Thermal injury:

• Thermal injury is usually to the bowel due to inadvertent use of electrocautery. The injuries are caused due to current diversion and active electrode. The injury is recognized, estimating the extent of the damage usually is difficult because the zone of dissection may exceed the area of visual damage.
• These thermal injuries can be prevented by adequate exposure of the operative field, performing the dissection near vital structures by scissors, clipping of blood vessels near the bowel rather than cauterizing them and judicious use of electrocautery by using short spurts of current.
• Principles of electrosurgical safety to be followed included use of electro surgical of acceptable standards, keeping instruments in good working condition with intact insulation, avoiding intra and extraperitoneal injuries from inadvertent activation, adequate exposure by panoramic view and using the ideal waveform and power output with appropriate active electrodes and technique.

5) Early and late post operative complications:

• Subcutaneous Emphysema:

• It commonly results from preoperational placement of an insufflation needle or leakage ofC02 around the cannula sites, the latter frequently because of excessive intraperitoneal pressure.
•  The emphysema can be readily identified by palpation of crepitus on the abdominal wall. If it extends into the mediastinum, it may lead to pneumothorax and cardio vascular collapse.
• Preventive measures include confirmation of intraperitoneal placement of needle, initiating insufflation at a low rate (1 lit/mill), confirming symmetrical abdominal distention and obliteration of liver dullness and operating at low intraperitoneal pressure after placement of all cannulas.
• In mild cases, no specific intra or postoperative therapy is required. But in severe cases the procedure is preferably terminated.

• Incisional Hernia and wound dehiscence.

• It is commonly seen in defects that are 10 mm or larger in size. Cases of bowel herniation and intestinal obstruction have been reported. These are mainly caused when the rectus sheath is not closed properly.
• Preventive measures include the use of smallest size cannula necessary for completing the procedure and adequate approximation of the rectus sheath under vision to ensure that bowel is not trapped inside. Even laterally placed 10 mm ports should be closed.

• Commonly seen after appendectomy more in infected and gangrenous cases. To avoid this, one must be careful in removing the appendix from the abdomen, taking care not to contaminate other tissues, and ensure that no fecal contamination or appendiceal fragmentation occurs during appendectomy. Abdominal irrigation is helpful in preventing the development of pelvic sepsis. Broad-spectrum antibiotics are indicated.

d) Ileus
May be due to excessive bowel manipulation or intraoperative contamination. Treatment includes nil by mouth, Nasogastnc aspiration and correction of hypokalemia, hypoproteinemia and early mobilization of the patient.

e) Wound infection

f) Complications specific to cholecystectomy:

Common bile duct injuries.

• Studies estimated the rate of bile duct injury during an open cholecystectomy to be from 0.053% to 0.6%,but the accepted standard is a rate of 0.1 % to 0.2%.(20,21,22,23) Laparo- scopic cholecystectomy, in contrast, is associated with a bile duct injury rate in the range of 0.2% to 2%.
•  Injury is broadly defined and includes everything from cystic bile-duct leaks to proximal segmental hepatic duct ligation and excision. Bismuth classified bile duct strictures on the basis of their location with respect to the hepatic duct confluence. However, biliary leaks (choledochal, hepatocystic, or sectoral) and isolated sectoral duct occlusions are not included in this classification scheme, and these account for a large proportion of the injuries following laparoscopic cholecystectomy.
• Strasberg's classification scheme, proposed in 1995, reflects the diversity of biliary injuries and their management(27). This scheme includes Bismuth's classification of strictures as its highest injury category.

Presentation, Mechanism and Management

Strasberg classification

The first repair has the greatest chance of success.

• Bismuth classification
• Stewart-way classification

Hepaticojejunostomy:

• Injury to common bile duct during surgery warrants a surgeon to do a reconstructive procedure. Hepaticojejunostomy is the procedure of choice for the CBD injury. Although different remedies have been ascribed for repair of CBD, but Hepaticojejunostomy still remains the gold standard procedure.
• The principle of the procedure is that a roux limb is created at a distance of about 40-50 cms. From the ligament of Treitz. Depending upon the Bismuth grade of injury to the CBD, the proximal part of CBD is so fashioned, that a end to side Hepaticojejunal anastomosis is done. The elementary limb of the jejunum is anastomosed end to side with roux limb of the jejunum at a distance of about 10-20 cms, from the Hepaticojejunal.

Recent advances

Single port laparoscopic cholecystectomy

• A new operating technique is gaining ground, which might be considered as a further evolution of Minimally Invasive, or Minimal Access Surgery. It is called by different names, but the principle remains the same:
• To further reduce the access trauma and the visibility of scars, by placing the access centrally and exclusively in the umbilicus. More specifically one might further distinguish single port and single site surgery. Whereas single port surgery - as indicated by its name - uses only a single, but relatively big device for access, single site surgery involves up to four trocars, but still exclusively placed through the umbilicus.

• Quite a few names have been coined in the meantime about it as SPA (Single Port Access), Single Access Surgery (SAS), E-NOTES (Embryonic-NOTES) or by similar terms, or S-PORTAL, or SILS (single incision laparoscopic surgery)
• One major difficulty in S-PORTAL procedures is the reduction of free maneuvering space and the potential collision of instruments and telescope.

Transumbilical approach provides the potential for no visible scar
Surgical incision may be hidden in the umbilicus
Minimizes the scars that may accompany additional sites of. entry
Potential for less post-operative pain due to the elimination of 3 additional puncture sites
Reticulating Instruments Provide Optimal Access and Ease of Use
0- to 80-degree articulation
Freedom of tip placement
360-degree rotation at all articulation angles
Spin-lock rotation position lock
Perform as a fully rigid straight instrument
Left- or right-hand versatility
Optimal access to difficult anatomy and maximum ease of use

Robotic surgery

• Robotic surgery, computer-assisted surgery, and robot-assisted surgery are terms for various technological developments that currently are developed to support a range of surgical procedures.
• Robot-assisted surgery was developed to overcome limitations of minimally invasive surgery, Instead of directly moving the instruments the surgeon uses a computer console to manipulate the instruments attached to multiple robot arms. The computer translates the surgeon's movements, which are then carried out on the patient by the robot. Other features of the robotic system include, for example, an integrated tremor filter and the ability for scaling of movements (changing of the ratio between the extent of movements at the master console to the internal movements of the instruments attached to the robot). The console is located in the same operating room as the patient, but is physically separated from the operative workspace. Since the surgeon does not need to be in the immediate location of the patient while the operation is being performed, it can be possible for specialists to perform remote surgery on patients. Robots can perform surgery without a human surgeon

Advantages and disadvantages

• Major advances aided by surgical robots have been remote surgery, minimally invasive surgery and unmanned surgery. Some major advantages of robotic surgery are precision, miniaturization, smaller incisions, decreased blood loss, less pain, and quicker healing time. Further advantages are articulation beyond normal manipulation and three-dimensional magnification, resulting in improved ergonomics. Robotic techniques are also associated with reduced duration of hospital stays, blood loss, transfusions, and use of pain medication.
• With a the cost of the robot at $1,200,000 dollars and disposable supply costs of $1,500 per procedure, the cost of the procedure is higher. Additional surgical training is needed to operate the system. Patient surveys indicate they chose the procedure based on expectations of decreased morbidity, improved outcomes, reduced blood loss and less pain. Higher expectations may explain higher rates of dissatisfaction and regret.

• The main advantage of this technique is that the incisions are very small and, consequently, patient recovery is quick. In traditional open-heart surgery, the surgeon makes a ten to twelve-inch incision, then accesses the heart by splitting the sternum (breast bone) and spreading open the rib cage. The patient is then placed on a heart-lung machine and the heart is stopped for the length of the surgery. Not only is this a way for bacteria that can cause infections to access the patient's body, it also leads to a painful wound, which takes time to heal.
• Because patient recovery after robot-assisted heart surgery is quicker, the hospital stay is shorter. On average patients leave the hospital two to five days earlier than patients who have undergone traditional open-heart surgery and return to work and normal activity 50%) more quickly. Reduced recovery times are not only better for the patient, they also reduce the number of staff needed during surgery, nursing care required after surgery, and, therefore, the overall cost of hospital stays.

In 2007, the. University of Illinois at Chicago medical team, lead by Prof. Pier Cristoforo Giulianotti, performed the world's first ever robotic pancreatectomy and also the Midwests fully robotic Whipple surgery. In April 2008, the same team of surgeons performed the world's first fully minimally invasive liver resection for living donor transplantation, removing 60% of the patient's liver, yet allowing him to leave the hospital just a couple of days after the procedure, in very good condition. Furthermore the patient can also leave with less pain than a usual surgery due to the four puncture holes and not a scar by a surgeon
                         

Conclusion.

Thus laparoscopic cholecystectomy has become the gold standard for treatement of gall stone disease. Knowledge of anatomy and anatomical varients goes a long way in avoiding complications during surgery and also management of post operative status.Robotics and single incision surgery , due to obvious benefits are here to stay and may soon become gold standards with decreasing costs and instrument innovations.