Laparoscopic pelvic lymphadenectomy versus traditional surgery in pigs
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British Journal of Obstetrics and Gynaecology October 1994, Vol. 101, pp. 901-902 SHORT COMMUNICATIONS Laparoscopic pelvic lymphadenectomy versus traditional surgery in pigs *NICHOLAS JOHNSON Senior Lecturer, **VALERIE JOHNSON Biological Scientist, ?GREG MCKIE Produci Speciahi, ??SIMON KNOWLES Head of Pathology * University of Leeds, UK and King Edward Hospital, Perth, Western Australia; ** Cottesloe, Western Australia; t Ethicon Endosurgery, West Perth, Austrulia; tt King Edward Memorial Hospital$or Women, Subiuco, Perth, Western Australia Pelvic lymphadenectomy for early cervical cancer is thought to be therapeutic, and gynaecological cancer surgeons are now performing this endoscopically (Garry 1992; Nezhat e? al. 1992, 1993; Dargent 1993; Querleu 1993). However, traditionalists have condemned the modern approach, believing that the harvest must be inferior compared with surgery through an abdominal incision. We tested this controversy by comparing the success of a laparoscopic and conventional lymph node harvest in an animal model. Subjects and methods The study protocol was reviewed and approved by the institution’s research board and animal licence guardians. The surgeon was trained in laparoscopic and radical surgery but had little experience of veterinary work. Knowledge of pig surgical anatomy was gained by performing a bilateral pelvic lymphadenectomy in a separate animal before the study. Six female pigs, aged between 15 and 26 weeks and weighing between 24 and 77 kg, were studied under general anaesthesia. The animal was in the Trendelenberg position, the surgical field was raised by lateral rotation, and a 4-port laparoscopy established. The field was prepared by a laparoscopic hysterectomy, oophorectomy, and laparoscopic exposure of one pelvic side wall. Each pig had a laparoscopic pelvic lymphadenectomy on one side, followed by midline laparotomy and clearance of the nodes from the other side. The side allocated for laparoscopic surgery was determined by a block (of 6) random code. After surgery, the vessels (lower aorta to femoral) were stripped from the posterior and, lower abdominal wall to assess if any nodes had escaped the harvest. All tissue was examined histopathologically. The node harvest and the unharvested nodes were counted by a pathologist who was unaware of the origin of each sample. The laparoscopic and conventionally obtained lymph node harvest was compared with nested ANOVA. Correspondence: Dr N. Johnson, Department of Obstetrics and Gynaecology, Leeds University, Leeds LS2 9NS, UK. Results The surgical approach made no detectable difference in the number of nodes removed from a pig’s pelvis. A total of 58 nodes were retrieved laparoscopically, compared with 48 through an incision (95 % CI for mean difference -2.3 to 4.6). A total of two nodes were left behind by laparoscopic surgery, compared with seven following open lymph- adenectomy. It is possible to clear the pelvis of lymph nodes endoscopically in a pig. The number of nodes removed from each animal and the number left behind is shown in Table 1. Three animals had a laparoscopic approach on the right and three on the left. The total number of nodes harvested from the left side of six pigs was 53, the same as on the right. The first bilateral laparoscopic operation was a training procedure and took five-and-three-quarter hours. It took an hour and a half, after establishing anaesthesia, to position the subject, set-up the instruments and ports, realise a urinary catheter was unnecessary, remove the uterus, and learn the anatomy. Subsequent unilateral laparoscopic lymphadenectomy took between one and a half and three hours, compared with less than one hour for conventional surgery. Discussion This study examines the assumption that laparoscopic lymphadenectomy generates an inadequate harvest com- pared with conventional surgery. These data show that this is not necessarily true. The pelvis can be cleared of lymph nodes and a comparable harvest can be achieved without opening the abdomen. However, this does not mean that gynaecological oncologists should abandon their scalpels and abdominal wall retractors. Surgery performed on pigs is comparable to surgery on humans, but there are gross anatomical differences. Not all units can be expected to have developed proficient laparoscopic skills or have the additional operative time or equipment at their disposal. There are problems with laparoscopic pelvic lymphadenectomy, but at least this study suggests that an inferior therapeutic clearance is not necessarily one of them. 90 1
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Transcript of Laparoscopic pelvic lymphadenectomy versus traditional surgery in pigs
British Journal of Obstetrics and Gynaecology October 1994, Vol. 101, pp. 901-902
SHORT COMMUNICATIONS
Laparoscopic pelvic lymphadenectomy versus traditional surgery in pigs * N I C H O L A S JOHNSON Senior Lecturer, * * V A L E R I E JOHNSON Biological Scientist, ? G R E G M C K I E Produci Spec iahi , ??SIMON KNOWLES Head of Pathology * University of Leeds, UK and King Edward Hospital, Perth, Western Australia; ** Cottesloe, Western Australia; t Ethicon Endosurgery, West Perth, Austrulia; tt King Edward Memorial Hospital$or Women, Subiuco, Perth, Western Australia
Pelvic lymphadenectomy for early cervical cancer is thought to be therapeutic, and gynaecological cancer surgeons are now performing this endoscopically (Garry 1992; Nezhat e? al. 1992, 1993; Dargent 1993; Querleu 1993). However, traditionalists have condemned the modern approach, believing that the harvest must be inferior compared with surgery through an abdominal incision. We tested this controversy by comparing the success of a laparoscopic and conventional lymph node harvest in an animal model.
Subjects and methods The study protocol was reviewed and approved by the institution’s research board and animal licence guardians. The surgeon was trained in laparoscopic and radical surgery but had little experience of veterinary work. Knowledge of pig surgical anatomy was gained by performing a bilateral pelvic lymphadenectomy in a separate animal before the study.
Six female pigs, aged between 15 and 26 weeks and weighing between 24 and 77 kg, were studied under general anaesthesia. The animal was in the Trendelenberg position, the surgical field was raised by lateral rotation, and a 4-port laparoscopy established. The field was prepared by a laparoscopic hysterectomy, oophorectomy, and laparoscopic exposure of one pelvic side wall. Each pig had a laparoscopic pelvic lymphadenectomy on one side, followed by midline laparotomy and clearance of the nodes from the other side. The side allocated for laparoscopic surgery was determined by a block (of 6) random code. After surgery, the vessels (lower aorta to femoral) were stripped from the posterior and, lower abdominal wall to assess if any nodes had escaped the harvest. All tissue was examined histopathologically. The node harvest and the unharvested nodes were counted by a pathologist who was unaware of the origin of each sample. The laparoscopic and conventionally obtained lymph node harvest was compared with nested ANOVA.
Correspondence: Dr N. Johnson, Department of Obstetrics and Gynaecology, Leeds University, Leeds LS2 9NS, UK.
Results The surgical approach made no detectable difference in the number of nodes removed from a pig’s pelvis. A total of 58 nodes were retrieved laparoscopically, compared with 48 through an incision (95 % CI for mean difference -2.3 to 4.6). A total of two nodes were left behind by laparoscopic surgery, compared with seven following open lymph- adenectomy. It is possible to clear the pelvis of lymph nodes endoscopically in a pig. The number of nodes removed from each animal and the number left behind is shown in Table 1.
Three animals had a laparoscopic approach on the right and three on the left. The total number of nodes harvested from the left side of six pigs was 53, the same as on the right. The first bilateral laparoscopic operation was a training procedure and took five-and-three-quarter hours. It took an hour and a half, after establishing anaesthesia, to position the subject, set-up the instruments and ports, realise a urinary catheter was unnecessary, remove the uterus, and learn the anatomy. Subsequent unilateral laparoscopic lymphadenectomy took between one and a half and three hours, compared with less than one hour for conventional surgery.
Discussion This study examines the assumption that laparoscopic lymphadenectomy generates an inadequate harvest com- pared with conventional surgery. These data show that this is not necessarily true. The pelvis can be cleared of lymph nodes and a comparable harvest can be achieved without opening the abdomen. However, this does not mean that gynaecological oncologists should abandon their scalpels and abdominal wall retractors. Surgery performed on pigs is comparable to surgery on humans, but there are gross anatomical differences. Not all units can be expected to have developed proficient laparoscopic skills or have the additional operative time or equipment at their disposal. There are problems with laparoscopic pelvic lymphadenectomy, but at least this study suggests that an inferior therapeutic clearance is not necessarily one of them.
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902 SHORT COMMUNICATIONS
Table 1. A comparison of the lymph node harvest obtained laparoscopically and through an abdominal incision. Each animal acted as its own control and had a laparoscopic and contralateral open lymphadenectomy in a single blind matched paired study using block random allocation.
Laparoscopic lymphadenectomy Lymphadenectorny through an abdominal incision
Approximate site Approximate site
Subject External Internal Common TOTAL External Internal Common
A 2 2 6 10 0 6 3 B 2 5 2 9 4 6 0 C 3 2 1 6 1 2 5 D 1 1 1 9 3 0 2 E 2 4 8 14 1 3 1 F 0 2 8 10 0 0 5
Total No. left behind l(PigF) 0 1 (PigB) 2 S(PigD&E) 0 2(PigB)
TOTAL
9 10 8 5
11 5 7
Acknowledgments We are grateful to Ethicon Endo-surgery, Australia and New Zealand, for supporting laparoscopic lympha- denectomy training in the Royal Perth Hospital Animal Research and Laboratory, and to the Royal College of Obstetricians and Gynaecologists for a travel scholarship.
References Dargent D. (1993) Laparoscopic surgery and gynaecologic cancer.
Garry R. (1992) Laparoscopic alternatives to laparotomy : a new Curr Opin Obstet Gynecol5, 294300.
approach to gynaecological surgery. Br J Obstet Gynaecol 99, 629-633.
Nezhat C. R., Burrell M. 0.. Nezhat F. R., Benign0 B. B. & Welander C. E. (1992) Laparoscopic radical hysterectomy with para-aortic and pelvic node dissection. Am J Obstet Gynecol. 166, 864865.
Nezhat C. R., Nezhat F. R. & Burrell M. 0. (1993) Laparoscopic radical hysterectomy and laparoscopic assisted vaginal radical hysterectomy with pelvic and para-aortic node dissection. JGynecol Surg 9, 105-120.
Querleu D. (1993) Laparoscopic para-aortic node sampling in gynaecological oncology : a preliminary experience. Gynecol Oncol 49, 24-29.
Received I3 April I994 Accepted 26 M a y 1994
British Journal of Obstetrics and Gynaecology October 1994, Vol. 101, pp. 902-904
Laparoscopic versus conventional pelvic lymphadenectomy for gynaecological malignancy in humans NICHOLAS JOHNSON Senior Lecturer & * Gynaecological Oncology Fellow Institute of Epidemiology, University of Leeh, UK and * King Edward Hospital, Perth, Western Australia
It is technically possible to perform laparoscopically a Subjects and methods Pelvic lymphadenectomy in Western Australia is per- formed as part of the treatment for early (Stage 1 and 2a) cervical cancer and for Stage 1 G3, M3 endometrial
during cervical or uterine cancer surgery in the Western Australian State Gynaecological Oncology Service was
complete pelvic lymphadenectomy. In the previous article, appearing on page 901 of this issue, laboratory animal experiments suggest that minimal access surgery is as good
was tested in clinical practice in a prospective observational study ‘Omparing the lymph node harvest from lapa-
as (Johnson ef 1994)* This carcinoma. The number of nodes harvested from women
roscopic bmphadenectomies and surgery’ recorded during a 12-month Deriod, from A ~ r i l 1993 to April 1994. A node was couited if it was palpated by a pathologist and confirmed on haematoxylin and eosin histology. Cases were contributed by three consultant surgeons, two of whom were experienced in oncology and
Correspondence: Dr N. Johnson, Department of Obstetrics and Gynaecology, ‘ D’ Floor, Clarendon Wing, Leeds Infirmary, Belmont Grove, Leeds LS2 9NS, UK.
