Port site metastases

BACKGROUND

Concerns about port site metastases have limited the application of minimally invasive surgery for intra-abdominal malignancies. The purpose of this review article was to summarize the current literature regarding port site metastases.

METHODS

A Medline search identified >100 articles in English published during the last 15 years regarding the history, incidence, etiology, and prevention of port site metastases. These articles were reviewed and are summarized.

RESULTS

The incidence of port site metastases, initially thought to be as high as 21%, is now thought to be closer to the incidence of wound metastases after open surgery. Multiple etiologic factors have been studied including direct wound contamination, surgical technique, effects of carbon dioxide pneumoperitoneum, and changes in host immune response. Various preventive measures have been proposed.

CONCLUSIONS

Port site metastases are a well-documented and devastating complication after laparoscopic resection of intra-abdominal malignancies. Although the etiology is not yet understood, a number of factors are contributory. All efforts should be made to prevent port site metastases.

Laparoscopic colon resection for colon cancer

INTRODUCTION

Laparoscopic colon resection for cancer is as yet an unproven operation. This review article summarizes current data on the topic.

METHODS

A Medline review identified articles published since 1990 summarizing patients with potentially curable colon cancer who underwent a laparoscopic-assisted colon resection. Only articles that were randomized or had a control group with historical or matched open cases were used.

RESULTS

Very few prospective randomized controls exist. Several clinical trials are under way with one completed. Data thus far support some patient benefits with a laparoscopic approach. No differences in morbidity, oncologic data, or survival appear to exist.

CONCLUSIONS

The results of ongoing clinical trials are still needed to further evaluate the role of laparoscopic assisted colon resection in patients with potentially curable colon cancer.

Incidental carcinoma of the gallbladder

Incidental gallbladder carcinoma (GBC) is a difficult management issue as there are no established guidelines. Laparoscopic cholecystectomy is associated with increased dissemination of the tumour cells (both in the peritoneal cavity and port sites). Depth of tumour invasion (T stage) and positive surgical margins are the most important prognostic factors, although tumour differentiation, lymphatic, perineural and vascular invasion may also affect the outcome. Simple cholecystectomy is adequate for mucosal (T1a) lesions only. For T1b tumours port site/wound excision with second radical operation (probably extended cholecystectomy -- wedge liver excision with regional lymphadenectomy) should be advised. T2 tumours should be treated with second radical operation (extended cholecystectomy or excision of medial liver segments 4b and 5 or 4, 5 and 8 with regional lymphadenectomy with or without excision of the extra-hepatic bile duct). Few T3 tumours can be cured and in some survival time may be prolonged by a second radical operation. More extensive liver resection (segments 4b and 5 or segments 4, 5 and 8) with regional lymphadenectomy with excision of the extra-hepatic bile duct should be advised. A second radical operation may palliate some T4 tumours. In the absence of extensive nodal disease, this operation may prolong the survival time. Excision of the extra-hepatic bile duct should be undertaken whenever the tumour involves the cystic duct margin or the extra-hepatic biliary tree. Epidemiology, risk factors, aetiopathogenesis and the modes of spread of GBC are discussed in relation to appropriateness of the second radical operation. Indications, types and role of the second radical operation are discussed.

Effect of laparoscopy on immune function

BACKGROUND

Laparoscopic surgery is believed to lessen surgical trauma and so cause less disturbance of immune function. This may contribute to the rapid recovery noted after many laparoscopic operations. Preservation of both systemic and intraperitoneal immunity is particularly important in surgery for sepsis or cancer and so an understanding of the impact of laparoscopy on immune function is relevant.

METHODS

Literature on immunological changes following laparoscopy and open surgery was identified from Medline, along with cross-referencing from the reference lists of major articles on the subject.

RESULTS AND DISCUSSION

Despite a few contradictory reports, systemic immunity appears to be better preserved after laparoscopic surgery than after open surgery. However, the local intraperitoneal immune system behaves in a particular way when exposed to carbon dioxide pneumoperitoneum; suppression of intraperitoneal cell-mediated immunity has been demonstrated in a number of studies. This feature may be clinically important and should be acknowledged when considering laparoscopic surgery in patients with malignancy or sepsis.

Metabolic and immunologic consequences of laparoscopy with helium or carbon dioxide insufflation: a randomized clinical study

BACKGROUND

Previous studies using animal models have demonstrated that carbon dioxide (CO2) pneumoperitoneum during laparoscopy is associated with adverse physiological, metabolic, immunological and oncological effects, and many of these problems can be avoided by the use of helium insufflation. The present study was performed in patients to compare the effect of helium and CO2 insufflation on intraperitoneal markers of immunological and metabolic function.

METHODS

Eighteen patients undergoing elective upper gastrointestinal laparoscopic surgery were randomized to have insufflation achieved by using either helium (n = 8) or CO2 (n = 10) gas. Intraperitoneal pH was monitored continuously during surgery, and peritoneal macrophage function was determined by harvesting peritoneal macrophages at 5 min and 30 min after commencing laparoscopy, and then assessing their ability to produce tumour necrosis factor-alpha (TNF-alpha), and their phagocytic function.

RESULTS

Carbon dioxide laparoscopy was associated with a lower intraperitoneal pH at the commencement of laparoscopy, although this difference disappeared as surgery progressed. The production of TNF-alpha was better preserved by CO2 laparoscopy, but the insufflation gas used did not affect macrophage phagocytosis. Patients undergoing helium laparoscopy required less postoperative analgesia.

CONCLUSION

The choice of insufflation gas can affect intraperitoneal macrophage function in the clinical setting, and possibly acid-base balance. The present study suggested no immunological advantages for the clinical use of helium as an insufflation gas. The outcomes of the present study, however, are different to those obtained from previous laboratory studies and further research is needed to confirm this outcome.

Laparoscopic port-site metastasis of an early stage adenocarcinoma of the cervix with negative lymph nodes

BACKGROUND

Port-site metastasis (PSM) following laparoscopic surgery for cancer is being increasingly recognized as a potential problem; the majority of cases appear following laparoscopy for a pelvic mass that subsequently proved to be malignant or in the case of a disseminated intraperitoneal disease. The rare cases of PSM following laparoscopy for endometrial and cervical cancer have all been associated with the presence of regional lymph node metastasis or disseminated disease in the peritoneal cavity. We present here a case report of PSM in the absence of spread beyond the primary tumor.

CASE

A 48-year-old woman with stage IA1 adenocarcinoma of the cervix was treated with laparoscopically assisted vaginal hysterectomy, bilateral salpingo-oophorectomy, and bilateral pelvic node dissection. The pathologic study revealed an endocervical adenocarcinoma confined to the cervix with negative lymph nodes. Nine months postoperatively, a cutaneous metastasis at the port-site was diagnosed. This was treated with wide local excision of the recurrence and the port-site track. Explorative laparotomy and para-aortic node sampling showed no evidence of recurrence elsewhere.

CONCLUSION

This case emphasizes the risk for PSM in laparoscopic surgery performed for early stage disease.

The virtues and pitfalls of minimally invasive surgery for gynecological malignancies: an update

Operative laparoscopy is still jockeying for its place in the surgical management of gynecological malignancies. Its usefulness in staging these malignancies continues to be investigated, as does its ability to convert abdominal procedures to vaginal procedures. Recent articles also address the role of operative laparoscopy in less common procedures, as well as the curiosity of investigators to gain a better understanding of the 'consequences' of operative laparoscopy by using animal models. The reader is updated by a review of the reports published over the past year and a half.

Port-site metastases following laparoscopic surgery

BACKGROUND

Application of laparoscopy to the resection of malignancy has been followed by a literature describing cases of metastatic involvement at laparoscopic port sites. These include patients who underwent surgery for early stage carcinoma and instances following laparoscopic procedures during which tumours were not dissected.

METHODS

Recently published clinical and experimental studies, and case reports related to this problem are reviewed; their relevance is discussed.

RESULTS

Experimental studies incorporating bench top and large animal models have confirmed that tumour cells may be redistributed to port sites during laparoscopic surgery either directly from contaminated instruments or indirectly via the insufflation gas. Small animal models suggest that the incidence of wound metastasis is increased following conventional laparoscopic surgery, and that it may be decreased by gasless laparoscopy or helium insufflation. This evidence suggests that the development of port-site metastases depends not only on the physical redistribution of tumour cells but also on the specific insufflation gas used, possibly because of influences on local metabolic or immune factors acting at the wound site.

CONCLUSION

Further research in this area is urgent. Until the issue is better understood, patients undergoing laparoscopic surgery for malignancy should be entered into clinical trials.

Wound metastasis after laparoscopy with different insufflation gases

BACKGROUND

There is growing evidence that laparoscopy for malignancy is associated with an increased incidence of metastasis to port sites. This study investigated the effect of different insufflation gases on port-site metastasis after laparoscopy in an established animal model.

METHODS

Forty-eight Dark Agouti rats with an established adenocarcinoma in the left flank underwent laparoscopic intraperitoneal tumor laceration. The gas used for insufflation was one of the following (12 rats in each group): (1) CO2, (2) N2O, (3) helium, or (4) air. Rats were killed 7 days after the procedure, and the port sites were examined for the presence of tumor metastasis.

RESULTS

Tumor involvement of port sites was significantly less likely after helium insufflation than in the other groups (p < 0.0001). There was no significant difference between the air, CO2, and N2O groups.

CONCLUSIONS

This study suggests that the development of metastases in port sites after laparoscopy may be influenced in part by the choice of insufflation gas used to create the pneumoperitoneum. In particular, helium was associated with a reduced rate of metastases.

Laparoscopic surgery: the effects of insufflation gas on tumor-induced lethality in nude mice

OBJECTIVE

The aim of the study was to examine the effect of helium (group 2), carbon dioxide (group 3), and heated carbon dioxide (group 4) pneumoperitoneum on survival in case of intraabdominal spread of tumor cells in nude mice.

STUDY DESIGN

The pneumoperitoneum was induced by a microhysteroflator with an intraperitoneal pressure of 8 mm Hg for 30 minutes. A washed tumor solution (0.4 ml) of a mesothelioma was injected intraperitoneally.

RESULTS

The survival rate of group 3 was significantly reduced compared with the controls (group 1) and group 4. The latter groups showed similar survival rates. In groups 2 and 3 no significant differences in survival rate were observed.

CONCLUSION

Clinical observations and the results of this animal study warn against the use of standard unheated carbon dioxide pneumoperitoneum in case of malignant tumors. Heated carbon dioxide seems to be advantageous.