Figure 23.17 Laparoscopic suturing instruments. The 3-mm and 5-mm diameter laparoscopic needle drivers are displayed in (A) and (C), while a knot manipulator is shown in (B) and inset left. The device is shown transferring a knot into the peritoneal cavity (inset right).
so-called ligating-cutting shears cut when high pressure is exerted in the handle by the surgeon (Fig. 23.16A–C).
Hemostatic clips may be applied with specially designed laparoscopic instruments. Nonabsorbable clips made of titanium are useful for relatively narrow vessels, and longer, delayed absorbable, self-retaining clips are generally preferred for larger vessels, 3 or 4 mm or more. Clips may be of particular value when securing relatively large vessels near an important structure such as the ureter.
Laparoscopic suturing is a method for maintaining hemostasis (95–97). Compared with clips or linear staplers, suturing has a relatively low materials cost, although operating time may be longer and more expensive. The two basic methods for securing a ligature around a blood vessel depend on where the knot is tied; ligatures are intracorporeal and extracorporeal. Intracorporeal knots replicate the standard instrument-tied knot and are formed within the peritoneal cavity. Extracorporeal knots are created outside the abdomen under direct vision and then transferred into the peritoneal cavity by knot manipulators (Fig. 23.17). Pretied knotted suture loops attached to long introducers, called Endoloops®, may be used to secure vascular pedicles. Care should be taken to make sure that they are tightly secured and that no other tissue is incorporated in the loop. A number of devices that facilitate the formation and tying of knots are either available or in development.
Small areas of low volume bleeding can be treated with topical hemostatic agents. Topical agents such as microfibrillar collagen are available in 5-mm and 10-mm diameter laparoscopic applicators (Fig. 23.13). Fibrin sealants (e.g., Tisseel®) and bovine thrombin and gelatin (Floseal®)can also be used. A solution of dilute vasopressin may be injected locally to maintain hemostasis for myomectomy or removal of ectopic pregnancy.
Tissue Extraction After excising tissue, it is usually necessary to remove it from the peritoneal cavity. Small samples can be pulled through an appropriate-sized cannula with grasping forceps; however, larger specimens may not fit. If the specimen is cystic, it may be drained by a needle or incised, shrinking it to a size suitable for removal through the cannula or one of the small laparoscopic incisions. If there is concern for malignancy, an alternative is to place the specimen in an endoscopic retrieval bag before drainage to prevent spillage (Fig. 23.18). More solid tissue may be morcellated with scissors, ultrasonic equipment, electrosurgery or electromechanical morcellators. If monopolar radiofrequency instruments are used for electrosurgical morcellation, the specimen must remain attached to the patient to preserve the integrity of the electrical circuit. Alternatively, special bipolar needles are available that do not require a dispersive electrode.
Figure 23.18 Specimen removal bag. This 10-mm diameter bag is positioned in the peritoneal cavity. Then the bag is deployed (insets), allowing the surgeon to place specimens for removal.