1. Urologic Pediatric Laparoscopy-Physiology and Complications Pediatric GU Review UCSD Pediatric Urology George Chiang MD Sara Marietti MD Outlined fromThe Kelalis-King-Belman Textbook of Clinical Pediatric Urology 2007 (not for reproduction, distribution, or sale without consent)

2. Pneumoperitoneum

Cardiac

Pulmonary

Renal

3. Cardiac

Mechanical compression of IVC

Reduction in Preload

Decreased CO and possibly BP

CO2 is a direct cardiovascular depressant

4. Cardiac

Reverse trendelenburg makes effects worse, trendelenburg makes them better

Volume loading prior to pneumoperitoneum can reduce effects (dehydration reduces preload)

Consider SCDs in older pt, longer cases, in reverse trendelenburg

Those with cardiac history may need invasive monitoring during the case

5. Pulmonary

Mechanical

Metabolic

6. Pulmonary-Mechanical

Pneumo pushes on diaphragm

Increased intrathoracic pressure

Observe increased peek expiratory airway pressure, decreased functional residual capacity

All effects worse while in trendelenburg

Trachea can be displaced anteriorly resulting in right bronchial intubation in infants

7. Pulmonary-Metabolic

Increased amount of CO2 gas that needs to be eliminated (children absorb more than adults)

Managed by increasing minute ventilation

Tight chest taping can further magnify thoracic problems

Those with pulmonary disease may retain CO2 longer and require post-op intubation and ventilation to clear the CO2

8. Renal

Increased intra-abdominal pressure compressed renal vasculature and parenchyma

Reduction in renal blood flow and perfusion

Negligible when intra-abdominal pressureis less than 10 mmHg

When greater than 15 mmHg, RBF, GFR, UOP all decrease

9. Renal

With desufflation of the abdomen, pressures return to normal

Diuresis may occur

NSAID increase medullary vasoconstriction and increase these effects

Important not to fluid overload based on oliguria alone (not indicator of intravascular volume), could cause potential pulmonary edema or CHF

10. Recommendations

Use lowest insufflation pressure possible to have adequate visualization

Infants~8 mmHg

Children~12mmHg

Adolescents~15mmHg

11. Complications

Access

Visceral Injury

Vascular Inury

Gas Embolism

Pain/Nausea/Vomiting

Conversion is not a complication

12. Access/Trocars

30% of complications happen upon initial access into the abdomen

76% of initial access injuries are to bowel or vascular structures

There is no great literature to support one form of access over another

13. Access

However, reusable trocars have shown more injury than disposable (more force)

Safety shields are not safe

14. Access-Anatomy

Umbilicus is located at level of aortic bifurcation, and where left common iliac vein crosses the midline

AP distance from umbilicus to aorta can be as close as 1cm in thin/sm patient

Lift abdominal wall

15. Hasson Technique

Direct open visualization layer by layer

Place trocar under direct visualization

Disadvantages - gas leak, increased incision size, increased time for placement

16. Optical Trocars

Place port with clear end, through which camera can visualize the layers

With or without veress insufflation

Decreased skin incision and air leakage

Disadvantage - difficulty in recognizing the layers (reports of major vascular injury with this technique)

17. Veress

Small skin incision is made, veress inserted

Left sub-costal region has been used because rarely adhesions, counter-traction

Umbilicus is the thinnest region of the body, even in obese people

18. Veress

Two pops - fascia and peritoneum

Abdominal wall should be stabilized while veress needle placed

Draw back, inject, drop test

Insufflation system that sounds with high pressure - extra peritoneal

Do not use reusable veress needles - dull

19. Access

Most common vascular injury is injury to inferior epigastic artery

Attempt intra-abd cautery, compression with cannula, foley with balloon up to tamponade, box-stitch (Carter-Thompson device)

20. Access

Major vascular injury usually more common with blind trocar placement

Decrease with 45 degree insertion angle

Recognize with aspiration of blood through veress needle or blood on initial visualization

Need prompt recognition and laparotomy

21. Access

Injury to bowel, stomach or bladder can be more difficult to identify - high rate of late presentation

If identified immediately, can repair intracorporally

Always inspect abdomen fully upon entering

22. Injury During Primary Access Journal of American College of Surgeons , 2001 23. Injury During Secondary Port Placement Journal of American College of Surgeons , 2001 24. Clinical Presentation Journal of Urology,1999 25. Access

Liver/Spleen injuries

Apply gentle pressure- fan retractor

Argon beam

Sealants

26. Gas Embolism

Rare

Direct insufflation into a vessel

Sudden decrease in end tidal CO2 and blood pressure

Trap gas in right ventricle (trendelenburg, left lateral decubitus)

27. Pain

Generally less than open surgery, but still significant

Shoulder pain felt to be from stretching peritoneum during insufflation

Reduction in pain score with:

Lower pressures, removal of gas at end ofprocedure, reducing size of trocars, local at port sites, irrigation of abdomen

28. Subcutaneous Emphysema

Crepitace under the skin

Generally not problematic

Insufflation outside of peritoneum with initial access or trocar leak

29. Port Site Hernia

Larger ports

Cutting vs dilating trocars

Midline vs lateral

Close 10mm or greater in adults

Close 5mm or greater in peds

? Close 3mm in infants