Radioimmunoguided surgery.

Although clinical staging of neoplastic diseases has long remained the only approach to prognosis and treatment, parameters for stage determination, such as tumor size (T) and lymph-node involvement (N), do not always provide effective indication of optimal treatment. Molecular medicine has also provided useful indications as to an alternative and/or integration to clinical staging. Despite the numerous possibilities afforded by pre-operative staging techniques, failures in defining the real spread of neoplasias into surrounding structures have remained a very important diagnostic problem. The labeling of monoclonal antibodies binding with neoplastic target cells by way of radioactive isotopes introduced the techniques known as immunoscintigraphy and SPECT, which then evolved into radioimmunoguided surgery. Fourty patients suffering from colorectal cancer whose age ranged between 42-82 years were singled out for this study. Before undergoing surgery, they were administered pancoloscopy and macrobiopsies, AP-LL chest x-rays, hepatobiliary ECT, echoendoscopy, abdomen and pelvis CT with nephrostographic phase, and total body bone scintigraphy. They were treated with 125I-B72.3 and 125I-FO23C5 (5% and 95% of patients, respectively). Thyrosuppression was achieved by Lugol solution (15 drops x 3/die) from the 6th day before infusion and until the day of surgical operation. Radioimmunoguided surgery (RIGS) has also been tested on staging and second-look of ovarian tumors. Five years after surgical operation the survival rate of Dukes A patients (15%) was confirmed to amount to 100%, whereas for Dukes B patients (50%) having undergone RIGS-guided exeresis on single unrecognized metastases (2 patients) and on unrecognized n+ (5 patients) the survival rate was found to be 85% after 5 years; 2 patients deceased due to relapse; 1 patient deceased due to e.p.a. Finally, for Dukes C patients; (35%) having undergone RIGS-guided exeresis on unrecognized liver micrometastases (1 patient), on single isolated metastases (2 patients) and in the occurrence of multicentric lymph-node positivity (9 patients), the survival rate after 5 years was found to amount to 64%; 5 patients deceased due to relapse. Out of 19 patients without pre-operative evidence of ovarian tumor as opposed to just 1 patient suspected of pelvic recurrence, after intra-operative surgical radicalization (45%), 1 patient was diagnosed fibrosis (suspicious lesion on CT) and 1 other patient peritoneal MTS (negative CT) by means of RIGS. RIGS has made it possible: to localize primary and/or metastatic lesions; to determine tumor-free margins, loco-regional disease spread; to differentiate suspicious foci on inspection and palpation (biotopic sampling); to detect invisible and impalpable tumor foci (occult sites); to verify radical exeresis; to evaluate lymphatic drainage stations; to enable guided exeresis of liver metastases.

Colorectal surgery: short-term prophylaxis with clindamycin plus aztreonam or gentamicin.

A randomized study was conducted to compare the effectiveness of aztreonam plus clindamycin with that of gentamicin plus clindamycin for prophylaxis of infection following colorectal surgery. A total of 138 patients undergoing elective colorectal surgery were randomized to treatment with clindamycin (600 mg) plus either aztreonam (1 g) or gentamicin (80 mg) 30 minutes before and 8 and 16 hours after surgery. The study included 122 patients (88.4%) with colorectal carcinoma. Samples from the abdominal cavity and from the subcutaneous tissues were taken for bacteriologic study. All samples from the abdominal cavity yielded microorganisms; both aerobic and anaerobic bacteria were isolated. Wound infections occurred in eight patients (12.1%) in the aztreonam group and in 12 patients (16.7%) in the gentamicin group. Escherichia coli, Bacteroides species, enterococci, and staphylococci were isolated most frequently from wounds and were often isolated from bacteriologic samples from the abdominal cavity of the same patients. The incidence of septic complications reflected the extent of nutritional and immunologic impairment. No significant differences were found between groups in the rate of urinary tract or lower respiratory tract infections. Aztreonam/clindamycin appears to be a valid alternative to gentamicin/clindamycin for the prophylaxis of infections following colorectal surgery.

Aztreonam versus gentamicin for short-term prophylaxis in biliary and gastric surgery.

Short-term antibiotic prophylaxis was studied in 80 patients undergoing biliary or gastric surgery. The patients were randomized to receive 1 g of aztreonam or 80 mg of gentamicin intravenously 30 minutes before surgery and 8 and 16 hours after surgery. Of samples taken from the abdominal cavity for bacteriologic study, 53% were culture positive. Wound infections developed in two (4.5%) of 44 patients receiving aztreonam and in seven (19.4%) of 36 patients treated with gentamicin. Staphylococcus epidermidis and Enterobacter species were isolated from sites of wound infection in the aztreonam group; Escherichia coli (two isolates), Pseudomonas aeruginosa (two isolates), Enterobacter species, Klebsiella species, Enterococcus faecalis, and Aeromonas hydrophila were isolated from the gentamicin group. Our data indicate that aztreonam is safe and effective for the prevention of infections following biliary and gastric surgery.