Comparison between two warm ischemic models in experimental liver transplantation in pigs

BACKGROUND

Experimental models of warm ischemia in liver transplantation have been employed to study the mechanisms and treatment of ischemia reperfusion injury.

METHODS

We compared a control group without (group A, n = 10) versus two models of warm ischemia of liver transplants in pigs: namely, occlusion of the hepatic artery and portal vein for 30 minutes (group B, n = 23) and extraction of the liver 60 minutes after cardiac arrest (group C, n = 5). Liver function tests, coagulation studies, and liver biopsies were performed during the first 24 hours post-liver transplant.

RESULTS

Clamping of the hepatic vasculature in group B produced a significant liver injury compared with the control group: elevation of the ALT and an abnormal 1-hour post-revascularization biopsy similar to that observed in the cardiac arrest group C. The transaminase levels were lower among group A animals (P <.05). But the hepatic synthetic functions as reflected in the protrombin time (PT) were not affected in group B versus group A. The alteration in PT with respect to the initial value was similar among group A and group B animals, which were significantly less than that in group C (P <.05).

CONCLUSIONS

Occlusion of the hepatic artery and portal vein, a simple surgical maneuver, causes moderate damage to a liver graft but less alteration of hepatic synthetic function. Clamping of the hepatic vasculture obtains more long-term survivors after OLT than cardiac arrest.

[Role of surgery in the treatment of primary gastric lymphoma]

Primary gastric lymphoma's optimum management remains controversial. We reviewed our series of 23 patients with primary gastric lymphoma treated in our hospital between 1976 and 1998 with surgery as main therapy. Ten patients underwent surgical resection alone, whereas 13 also received postoperative adjuvant therapy, depending on the oncologist-haematologist's recommendations. No differences were found between treatments regarding mortality and morbidity. Clinical-histological features and patients, follow-up are analyzed. No patient died because of lymphoma and there wasn't either local or distant recurrence. We consider that surgery remains a valid option for the primary gastric lymphoma treatment. The introduction of combined modalities of radiation therapy and chemotherapy will depend on the final stage, the tumor histological features, and the feasibility of getting a radical resection.

Repair of ventral hernias with expanded polytetrafluoroethylene patch

BACKGROUND

Operations for large and recurrent abdominal hernias have a high associated recurrence rate, although it is lower when prosthetic material is used. Expanded polytetrafluoroethylene (ePTFE) seems to be the best tolerated prosthetic material in surgery.

METHODS

A series of 45 ventral hernias repaired using ePTFE for closure or reinforcement of the herniorrhaphy has been evaluated prospectively. Thirty-six were midline incisional hernias and nine were transverse or pararectal ventral hernias. There were 13 recurrent ventral hernias and three defects were operated as an emergency procedure. The patch was sutured to the anterior aponeurosis with a running non-absorbable suture. Some other kind of intra-abdominal procedure was undertaken in 12 cases.

RESULTS

ePTFE was well tolerated. Complications occurred in five patients. Major complications were found in three patients: cutaneous necrosis requiring a myocutaneous flap; and infection of the prosthesis (primary, and secondary to enterocutaneous fistula due to diverticulitis, both requiring removal of the patch). Mean follow-up was 39 months and hernia recurrence occurred in only one patient.

CONCLUSION

This clinical experience shows that ePTFE is a very reliable prosthetic material for the repair of abdominal wall hernias.

[Follow-up of breast cancer: review of 750 cases after 5 years]

Recurrence of breast cancer can present in very small tumors even 20 years after initial treatment. Periodic revision of all the operated population during a long time will be necessary to detect all the recurrences. For this the cost-benefit relation of follow-up in breast cancer is a controversial topic. We present our results in 750 cases of breast cancer operated from 1980 and submitted to a follow-up protocol during five years. We analyzed the value of follow-up for the discovery of metastases, local recurrence after conservative treatment and after mastectomy. Finally we considered the usefulness of early diagnosis of familial breast cancer and cancer in the contralateral breast. Metastases was discovered in asymptomatic patients in 68%, which could improve the survival. Recurrence after mastectomy was seen in 1.3% of the patient and a half of these after treatment presented survival superior to 3 years. Follow-up favours early diagnosis and could have influence on survival.

[Breast cancer: value of various examinations in the diagnosis of the primary lesion]

Breast physical examination which is enormous help in clinical diagnosis of cancer of the breast is not useful in the diagnosis of early lesions. We analized in this study different complementary examinations we do for the diagnosis of the cancer of the breast. Mammography, though maintaining a 5-7% false negative results is the examination of choice of the breast. Not with standing its simplicity, its contribution with respect to breast and neoplastic biology makes it a useful investigation. The diagnosis obtained through mammography in non palpable tumors permit the use of conservative therapeutic techniques at the same time allowing improvement in curation and survival rates when we deal preferently with Stage I cancer. It is still necessary in our means an information-sensibilization of the female population about breast autoexamination and the need for early specialized medical consultation. Any abnormal breast sign should alert us that more than 2.5 months delay would suppose a difference from a T1 to a T2 tumor.

[Role of extended type R2 lymphadenectomy in the surgical treatment of resectable gastric cancer]

The extended lymphadenectomy has been proposed as routine procedure in the surgical treatment of gastric cancer, although some controversies have been published. We present a retrospective analysis on the impact of extended lymph node dissection after total gastrectomy, in terms of post-operative course and histopathologic findings, in a group of 30 patients with R2 lymphadenectomy and in 16 patients with R1 lymphadenectomy. There were no significant differences in duration of operation, amount of blood transfusion and length of hospital stay between the 2 groups. The only significant difference was found in the greater amount of drainage output after R2 lymphadenectomy as compared with R1. There were no mortalities in either group and morbidity rate was similar for both [43% in R1 and 40% in R2) mostly in the form of abdominal infections (18% in R1 and 16% in R2]). A significantly greater number of lymph nodes was identified after R2 gastrectomy. Fifty-three per cent of patients has positive lymph nodes, 12% of them being from the N2 echelon of nodes (including one case of early gastric cancer). Careful lymph node dissection in gastric cancer surgery allows a more precise staging of the tumor with no increase in postoperative morbidity.

[Technique and function of an experimental multiorgan transplant model in pigs]

En bloc transplantation of the liver, duodenum and pancreas has been successful in humans for the treatment of tumors requiring exenteration of the upper abdomen. We have developed an experimental model in 40 pigs of en bloc transplantation of the liver, duodenum and pancreas. The surgical technique for organ harvesting and preservation has been correct as the early graft function was excellent. We describe in detail the surgical technique in the recipient animal, the anesthetic model and the autopsy findings. Liver function was excellent and endocrine pancreatic function was normal within 8 hours after transplantation. Absorption and insulin-secreting response was normal in a few animals studied with an oral glucose overdose and with the intravenous glucagon test.

[Cancer of the esophagus (I): its epidemiological, clinical and diagnostic assessment according to histological type]

From 1975 to 1991, sixty-eight patients were treated with surgery for esophageal cancer at the Clínica Universitaria de Navarra. This study involves an analysis of epidemiologic and predisposing risk factors in relation with the histologic type of tumor: epidermoid carcinoma vs. adenocarcinoma. The difference in mean age of males (60.5 yrs.) as compared with that of females (48.7 yrs.) was statistically significant (p < 0.05). Likewise, the mean age of patients with epidermoid carcinoma (57.8 yrs.) was significant lower (p < 0.01) as compared with that of those with adenocarcinoma (66.3 yrs.). Smoking and alcoholism were common in the group of patients with epidermoid carcinoma, while Barrett's esophagus and hiatal hernia were frequently seen in patients with adenocarcinoma. Dysphagia was the most frequent symptom both at the start of disease (75%) and with the diagnosis established (96.7%). There was no significant difference in the symptomatology of patients with one type of tumor or the other. The efficacy of ancillary diagnostic procedures such as barium swallow, esophagoscopy, computerized tomography and biopsy were likewise assessed. The most frequent site of tumor was at the middle third, with majority of patients being at clinical stage 1-2 of disease at the time of diagnosis.