Patient Selection And Technique

In selecting patients for laparoscopy, it is important to consider the overall plan for the patient with malignant disease which would include the possibility of surgical extirpation, chemotherapy or radiation. In patients who present with as-cites, the opportunity for curative resection becomes less although appropriate treatment strategies may be undertaken if the etiology of the ascitic fluid becomes known. While laparoscopy itself may be the prime mode of detection and confirmation of malignancy, more often patients who undergo laparoscopic examination have had a previous histologic confirmation by gastrointestinal endoscopic techniques or peripheral node biopsy. Every physician-endoscopist undertaking laparoscopy should have a clear understanding of the benefits offered by the procedure and should be willing to recommend avoidance of the technique if there is no defineable gain for the patient.

Diagnostic laparoscopy in the assessment of ascites or peritoneal malignancy may be undertaken using general anesthetic techniques or local infiltration with intravenous sedation in the awake patient. While some have favored the local anesthetic approach,9 the necessity for creation of pneumoperitoneum and careful intra-abdominal assessment with biopsy may require prolonged periods of examination which can only be accomplished under general anesthetic techniques. While small laparoscopic cameras and instrumentation have become available for utilization outside the operating room setting, patients undergoing diagnostic lap-aroscopy may also need immediate celiotomy as the next step in full diagnosis or therapy. In our experience, therefore, these techniques are best performed in the operating room setting.

Patients who have had previous abdominal procedures should be evaluated carefully for alternate sites of placement of the initial puncture for establishing pneumoperitoneum. As the skill of the endoscopist increases, patients having previous operations for both benign and malignant processes may be approached, especially to satisfy the need for a "second look" rather than a formal celiotomy. In order to establish a safe pneumoperitoneum in a patient with a previously operated abdomen, open techniques using a Hasson cannula and adjunctive methods using ultrasound have been recommended to avoid inappropriate trocar placement. The location for placement of the Veress needle to establish a pneumoperi-toneum may be determined by the site of the previous incision or by characteristics revealed by the abdominal ultrasound or computed tomography scan.

Selection of patients and the technique utilized for laparoscopy in the assessment of patients with ascites and potential peritoneal malignancy depend heavily on the information to be gained from the study. In patients with significant cardiac and respiratory disease who would not be candidates for open abdominal procedures because of the requirements for general anesthesia, laparoscopy may in fact prove hazardous because of the need for both general anesthesia and a significant pneumoperitoneum. Distention of the abdomen may in fact reduce cardiac output and enhance arrhythmias and may be considered a contraindication in those with severe coronary artery disease.10 Similarly, profound problems in coagulation should encourage either correction of clotting problems preopera-tively or abandonment of techniques that would increase bleeding. In patients with ascitic collection from both cirrhosis and hepatoma for instance, (Fig. 3.4) these coagulation problems must be corrected with fresh frozen plasma or vitamin K prior to any diagnostic procedure. In any patient with ascitic collections, a thorough history and physical examination are required to evaluate a patient for diagnostic laparoscopy and should be prerequisites to determine the appropriateness of this procedure.

One of the most important current utilizations of diagnostic laparoscopy is in the assessment of patients who may have metastatic disease to the liver. These patients may present with ascitic collections and have negative radiographic studies. Since most involved lymph nodes and metastatic deposits less than 1.5 centimeters are not routinely evident on CT scanning,11 the laparoscope may be important in uncovering these implants. The full assessment of these patients must be performed using a complement of laparoscopy and imaging techniques since the laparoscope is only able to visualize surface lesions, even though these implants may be quite small. Similarly, it is difficult to assess the retroperitoneum

Fig. 3.4. Advanced cirrhosis and hepatoma diagnosed by directed laparoscopic biopsy after correction of coagulation defects.

Fig. 3.4. Advanced cirrhosis and hepatoma diagnosed by directed laparoscopic biopsy after correction of coagulation defects.

fully using laparoscopic means, but these techniques are improving because of the addition of newer technology such as laparoscopic-assisted ultrasonography.12 In the diagnostic evaluation of patients with ascites, consultation with radiologic colleagues is important to define whether computed tomography, magnetic resonance imaging, percutaneous ultrasound, or nuclear medicine studies should be performed to complement laparoscopic evaluation.

Ascitic fluid collection is most often seen in the presence of hepatic cirrhosis, but other causes of benign peritoneal fluid collection do occur. Traditional paracentesis has been used as a diagnostic and therapeutic maneuver, but relies on "blind" approaches to the abdominal cavity which may produce intestinal, biliary, or vascular complications. Since fluid obtained in this manner is studied by cyto-logical methods, false negative determinations occur secondary to sampling and interpretative limitations. If examination of ascites supports underlying benign liver or renal disease, there may be little additional role for laparoscopic evaluation. Direct evaluation of the peritoneal cavity is indicated when the etiology of ascites is unclear or when imaging studies indicate findings in addition to cirrhosis alone.

Infectious causes of ascites may warrant examination beyond percutaneous aspiration of fluid. In many countries around the world, tuberculosis and parasitic infestation may be associated with ascites and may actually mimic malignant cachectic processes. In the United States, tuberculous peritoneal involvement has been seen to increase in populations that are immunosuppressed. These patients present difficult diagnostic dilemmas because of the frequent spectre of cancer associated with immunocompromised states. Evidence in both the laboratory and in human studies supports laparoscopic evaluation rather than open celiotomy because of the reduced effect of minimal access maneuvers on the immune system.13

The evaluation of patients with ascitic fluid collections should be as rigorous for laparoscopic procedures as those performed for major surgical resections. As stated above, general anesthesia is frequently required because of the need for performance of pneumoperitoneum, abdominal relaxation and length of intraabdominal examination required to avoid missing small occult lesions. Assessment of cardiac and pulmonary function is important to avoid post-procedure complications. Radiographic evaluation of the chest is mandatory to determine whether pleural effusion is present along with abdominal fluid collections. Diagnostic or therapeutic thoracentesis should be performed when necessary with full radiologic evaluation afterward to insure that pneumothorax has not resulted. Pre-laparoscopic determination of coagulation abnormalities, especially in patients with underlying hepatic disease is important. Assessment of prothrombin time and partial thromboplastin time as well as platelet count should be routinely performed.

Technical issues relative to laparoscopic evaluation of ascitic fluid are important, especially to avoid the unwanted complication of infected ascites or post-procedure ascitic leak. Prior to laparoscopic evaluation, it is helpful to perform a paracentesis to reduce the amount of intra-abdominal fluid and the potential problem noted when carbon dioxide is placed intra-abdominally. This could result

in the unwanted phenomenon of bubbling as a result of gas instillation which will interfere with the visual interpretation needed for laparoscopy. An important technical point is to position the patient in reverse Trendelenburg when placing a Veress through a midline infra-umbilical approach. This will allow the abdominal contents, especially loops of intestine, to float on the top of the ascitic fluid collection and, therefore, reduce the potential hazard of intestinal puncture when the Veress needle is directed toward the pelvis. This is opposite to the traditional method of positioning the patient in Trendelenburg position which allows the gravity to help keep intestinal contents out of the pelvic region when routine laparoscopy is performed.

Careful assessment of the entire intra-abdominal area is important to find small implants which may give valuable information as to the cause of the ascitic collection. One confounding problem is the appearance of tuberculous peritonitis which may mimic small implants seen frequently in pancreatic or gastric cancer.14 Biopsy of implants using cupped biopsy forceps with the application of cautery is necessary during the procedure. In addition, wedge or needle biopsy of suspicious hepatic lesions must be performed. One must remember not to allow cautery application to destroy the architecture of small implants, thereby limiting histologic assessment. Pre-laparoscopy evaluation of coagulation parameters, as noted above, is important prior to any hepatic biopsy.

At the conclusion of the laparoscopic evaluation, careful closure of abdominal trocar sites is mandatory. Fascial and subcutaneous approximation as well as secure skin closure should be performed routinely in order to reduce leakage of peritoneal fluid. Since the development of trocar site recurrence from malignancy is increased in this setting,15 careful irrigation of all trocar sites utilizing both saline and sterile water is recommended. The water will hopefully lyse isolated malignant cells in the abdominal wound areas.

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