Lecture on Minimal Access Surgery Day Part 1

Undergraduate level lecture on Minimal invasive surgery

1. MINIMAL ACCESS SURGERY Dr. Bikramjit Maity

2. Learning objectives Principles of minimal access surgery Advantages and disadvantages Indications Safety issues Perioperative assessment Recent advances Application of artificial intelligence

3. DEFINITION “Small holes, big operations” Performing operation through small incision Use of miniaturized high-tech imaging system Accomplish surgical therapeutic goals with minimal somatic and psychological trauma

4. HISTORY 1901- Kelling, placed a cystoscope within inflated abdomen 1910- Jacobeus, thoracoscopy using a cystoscope Late 1950s- Hopkins, described Rod Lens- transmitted light through a solid quartz rod with no heat or little light loss 1980s- development of high resolution charged couple devices 1987- Mouret, first video assisted laparoscopic cholecystectomy

5. ROOM SET-UP Patient interposed between surgeon and video monitor Ideally operative field also between surgeon and monitor Insufflating and patient monitoring equipment placed across table from surgeon

6. IMAGING SYSTEM Camera with charged couple device CCD- Array of photosensitive sensor element(pixel) that convert the incoming light intensity to an electric charge Digital enhancement- detect edges where there are drastic color or light changes between adjacent pixels High Definition Chip- increases lines of resolution from 480 to 1080 lines

7. PRINCIPLES OF ACCESS Open Hasson technique- direct peritoneal access under direct vision Veress needle- two distinct pops felt- abdominal wall fascia and peritoneum Abdomen insufflated to 14-15mm Hg Direct access to abdomen using radially dilating sheath over veress or optiport Usual access is at umbilical region Palmer point- entry in left upper quadrant of abdomen , 3cm below costal margin, in mid clavicular line

8. Trocar and Cannula Veress Needle

9. ENERGY SOURCES Monopolar and bipolar electrosurgery Advanced energy source with ability to selectively use bipolar energy and combine it with compressive forces and a controllabe blade

10. Effect of pneumoperitoneum by CO2 Gas specific effects: Respiratory Acidosis Anesthesiologist increases ventilatory rate and vital capacity If RR required > 20/min indicate less efficient gas exchange If VC increased substantially- chances of barotrauma and motion induced disruption of operative field Severe respiratory acidosis lead to arrhythmia PHYSIOLOGY and PATHOPHYSIOLOGY

11. Pressure effects of pneumoperitoneum Decreased venous return and decreased cardiac output due to excessive pressure on IVC and reverse Trendelenberg position Vasovagal response with bradycardia and hypotension due to rapid stretch on peritoneal membrane With increased IAP, diminished venous return from lower extremity Risk of venous thrombosis Increased IAP decreases renal blood flow, GFR and urine output

12. Operative problems Intraoperative perforation of a viscus or vascular injury Bleeding Bleeding from organs encountered during surgery Bleeding from a trocar site

13. Intraoperative perforation of a viscus or vascular injury Perforation of any viscus, such as bowel, is a potential hazard that may occur inadvertently May go unrecognised or require emergency conversion

14. BLEEDING Risk Fasctors - liver disease, coagulation disorder, acute inflammation Damage to a large vessel requires immediate assessment Relatively low threshold for early conversion control may be achieved by clipping, stapling or use of an energy device, depending on vessel size. When the vessel is not identified, compression should be applied immediately with a blunt instrument, a cotton swab or with the adjacent organ

15. Surgicel® , tissue glues or other haemostatic agents may also be used to aid haemostasis, e.g. from the gallbladder bed during cholecystectomy. Bleeding from the trocar sites is usually treated by localised diathermy or applying upwards and lateral pressure with the trocar itself. If bleeding vessel cannot be easily identified, mass ligation of the vessel around the port site can be performed Catheter is introduced into the abdominal cavity through the bleeding trocar site wound, the balloon is inflated and traction is placed on the catheter, which is bolstered in place to keep it under tension. The catheter is left in situ for 24 hours and then removed.

16. Principles of electrosurgery during laparoscopic surgery Inadvertent electrosurgical injuries are potentially serious often unrecognised at the time inadvertent touching or grasping of tissue during current application direct coupling between tissue and a metal instrument insulation breaks in the laparoscopic instrument direct sparking from the diathermy probe capacitive coupling Bipolar diathermy is safer and should be used in preferencen to monopolar diathermy, especially in anatomically crowded areas.

17. POSTOPERATIVE CARE Nausea - almost 50% experience after MIS, usually respond to ondansetron Shoulder tip pain - pain is referred from the diaphragm, usually settles within 2–3 days and is relieved by simple analgesics Port site pain Analgesia - t ype and extent of analgesic requirement will depend on both the patient and procedural factors Orogastric or nasogastric tube - may be placed for some abdominal surgery if the stomach is distended and obscuring the view

18. Oral fluids - resume oral fluids assoon as they are conscious; they usually do so 4–6 hours after the end of the operation Oral feeding - l ight meal can be taken 4–6 hours after the operation Drains - exact location and size of any drains should be clearly documented in the operation notes and the tubing labelled accordingly.