pedi gu review laparoscopy

Urologic Pediatric Laparoscopy-Physiology and Complications

Pediatric GU ReviewUCSD Pediatric Urology

George Chiang MDSara Marietti MD

Outlined from The Kelalis-King-Belman Textbook of Clinical Pediatric Urology 2007

(not for reproduction, distribution, or sale without consent)

Pneumoperitoneum

• Cardiac• Pulmonary• Renal

Cardiac

• Mechanical compression of IVC

• Reduction in Preload

• Decreased CO and possibly BP

• CO2 is a direct cardiovascular depressant

Cardiac

• Reverse trendelenburg makes effects worse, trendelenburg makes them better

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

• Consider SCD’s in older pt, longer cases, in reverse trendelenburg

• Those with cardiac history may need invasive monitoring during the case

Pulmonary

• Mechanical

• Metabolic

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

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

Renal

• Increased intra-abdominal pressure compressed renal vasculature and parenchyma

• Reduction in renal blood flow and perfusion• Negligible when intra-abdominal pressure is

less than 10 mmHg• When greater than 15 mmHg, RBF, GFR, UOP

all decrease

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

Recommendations

• Use lowest insufflation pressure possible to have adequate visualization

• Infants~8 mmHg• Children~12mmHg• Adolescents~15mmHg

Complications

• Access• Visceral Injury• Vascular Inury• Gas Embolism• Pain/Nausea/Vomiting• Conversion is not a complication

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

Access

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

• Safety shields are not safe

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

Hasson Technique

• Direct open visualization layer by layer• Place trocar under direct visualization• Disadvantages - gas leak, increased incision

size, increased time for placement

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)

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

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

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)

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

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

Injury During Primary Access

Journal of American College of Surgeons, 2001

Injury During Secondary Port Placement

Journal of American College of Surgeons, 2001

Clinical Presentation

Journal of Urology, 1999

Access

• Liver/Spleen injuries• Apply gentle pressure - fan retractor• Argon beam• Sealants

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)

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 of

procedure, reducing size of trocars, local at port sites, irrigation of abdomen

Subcutaneous Emphysema

• Crepitace under the skin• Generally not problematic• Insufflation outside of peritoneum with initial

access or trocar leak

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