Intra-operative parathyroid hormone monitoring in patients with parathyroid cancer

BACKGROUND

Intra-operative parathyroid hormone (PTH) monitoring (IPM) is 97% accurate in predicting postoperative eucalcemia in sporadic primary hyperparathyroidism (SPHPT). However, its usefulness in parathyroid cancer has not been demonstrated. This study reports IPM accuracy during surgical resections for parathyroid cancer.

METHODS

Eight of 556 consecutive patients with SPHPT underwent parathyroidectomy using IPM and had parathyroid cancer. Operative success was defined as eucalcemia > six months and operative failure/persistent cancer as hypercalcemia within six months of parathyroidectomy. The IPM criterion for operative success was defined as a >50% decrease of peripheral PTH levels from the highest either pre-incision or pre-excision values, 10 minutes after resection.

RESULTS

In eight patients, 11 operations were performed. Ten operations (91%) resulted in >50% intra-operative PTH decrease. However, in only seven (70%) of these resections, eucalcemia was achieved for >6 months with five of these seven (71%) procedures being initial en bloc resections. The remaining 3/10 (30%) operations with >50% intra-operative PTH decrease resulted in operative failures. In the last operation, intraoperative parathormone monitoring (IPM) correctly predicted operative failure. IPM sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy in predicting outcome were 100, 40, 70, 100, and 75%, respectively.

CONCLUSIONS

IPM with the criterion of >50% PTH drop from the highest level is less accurate in predicting operative success in parathyroid cancer when compared to SPHPT. A >50% intra-operative PTH level decrease in patients with parathyroid cancer, particularly in reoperative cases, is less predictive of complete resection. The initial recognition of this disease followed by proper resection remains essential in the treatment of parathyroid cancer.

Preoperative esophageal manometry and outcome of laparoscopic adjustable silicone gastric banding

BACKGROUND

Laparoscopic adjustable silicone gastric banding (LASGB) for morbid obesity has been reported to provide long-term weight loss with a low risk of operative complications. Nevertheless, esophageal dilation leading to achalasia-like and reflux symptoms is a feared complication of LASGB. This study evaluates the clinical benefit of routine preoperative esophageal manometry in predicting outcome after LASGB in morbidly obese patients.

METHOD

A review of prospectively collected data on 77 patients who underwent routine esophageal manometry prior to LASGB for morbid obesity from February 2001 to September 2003 was performed. Aberrant motility, abnormal lower esophageal sphincter (LES) pressures, and other nonspecific esophageal motility disorders noted on preoperative esophageal manometry defined patients of the abnormal manometry group. Outcome differences in weight loss, emesis, band complications, and gastroesophageal reflux disease (GERD) resolution or improvement were compared between patients of the abnormal and normal manometry groups after LASGB. Analysis of variance (ANOVA) and chi-square tests were performed to determine the significance of these outcomes.

RESULTS

Of the patients tested, 14 had abnormal esophageal manometry results, whereas 63 had normal manometry results before LASGB. There was no significant difference in percent excess weight loss (%EWL) at 6 and 12 months between the groups after gastric banding. Severe postoperative emesis occurred more frequently in patients with abnormal manometry results than in those with normal manometry results. There were two band-related complications, both of which occurred in patients of the normal manometry group.

CONCLUSIONS

Preoperative esophageal manometry does not predict weight loss or GERD outcomes after LASGB in morbidly obese patients. Postoperative emesis was more common in patients with abnormal manometry findings, but such symptoms were manageable and did not lead to poor weight loss or to band removal or increased band-related complications.

Construct validity for the LAPSIM laparoscopic surgical simulator

BACKGROUND

The skills required for laparoscopic surgery are amenable to simulator-based training. Several computerized devices are now available. We hypothesized that the LAPSIM simulator can be shown to distinguish novice from experienced laparoscopic surgeons, thus establishing construct validity.

METHODS

We tested residents of all levels and attending laparoscopic surgeons. The subjects were tested on eight software modules. Pass/fail (P/F), time (T), maximum level achieved (MLA), tissue damage (TD), motion, and error scores were compared using the t-test and analysis of variance.

RESULTS

A total of 54 subjects were tested. The most significant difference was found when we compared the most (seven attending surgeons) and least experienced (10 interns) subjects. Grasping showed significance at P/F and MLA (p < 0.03). Clip applying was significant for P/F, MLA, motion, and errors (p < 0.02). Laparoscopic suturing was significant for P/F, MLA, T, TD, as was knot error (p < 0.05). This finding held for novice, intermediate, and expert subjects (p < 0.05) and for suturing time between attending surgeons and residents (postgraduate year [PGY] 1-4) (p < 0.05).

CONCLUSIONS

LAPSIM has construct validity to distinguish between expert and novice laparoscopists. Suture simulation can be used to discriminate between individuals at different levels of residency and expert surgeons.

Complete 5-year follow-up of a prospective phase II trial of preoperative chemoradiotherapy for esophageal cancer

BACKGROUND

Conclusive evidence supporting the routine use of multimodality therapy in esophageal cancer is lacking. However, since long-term survival after esophagectomy alone is unusual, clinical trials designed to identify effective therapeutic regimens are essential. We report here the 5-year results of a phase II induction chemoradiotherapy trial.

METHODS

From August 1991 to January 1995, 44 patients with esophageal or gastroesophageal junction carcinoma were treated with a combination of 5-fluorouracil, cisplatin, and interferon-alpha with concurrent external beam radiotherapy.

RESULTS

Forty-one (93%) patients completed chemoradiotherapy, with most toxic events recorded as grade I or II. Curative resection (all gross tumor removed) was achieved in 36 of 37 surgical explorations, with 10 tumors demonstrating complete pathologic response and 23 showing partial pathologic response. Median follow-up for survivors was 75 months (range, 60-100 months). Five-year survival for all patients was 32%, with a median survival of 28 months. Five-year disease-free survival in patients with curative resection was 36% (median, 26 months) and overall survival was 39% (median, 34 months). Five-year survival for patients with curative resection whose disease responded to chemoradiotherapy was 42% (median overall survival, 36 months). Local-regional recurrence alone occurred in 3 patients, distant failure alone in 12 patients, and combined local-regional and distant failure in 2 patients. A Cox proportional hazards model identified both pathologic tumor and nodal stage as independent predictors of disease-free survival. Fourteen patients (32%) were 5-year survivors; 1 of these patients later experienced disease recurrence and died.

CONCLUSIONS

Preoperative chemoradiotherapy can result in a long-term and durable disease-free state. Only large, multi-institutional phase III trials can determine whether combined modality therapy is superior to resection alone.

Long-term survival following induction chemoradiotherapy and esophagectomy for esophageal carcinoma

HYPOTHESIS

Long-term survival is rare in patients treated for esophageal carcinoma. Several clinical trials suggest the possibility of prolonged survival in patients who undergo induction chemoradiotherapy plus esophagectomy.

DESIGN

Prospective uncontrolled study.

SETTING

University hospital.

PATIENTS AND METHODS

Forty-four patients with carcinoma of the esophagus or gastroesophageal junction were prospectively entered into a phase II trial of preoperative 5-fluorouracil, cisplatin, and interferon alfa with concurrent external beam radiotherapy before esophagectomy. Curative resection was performed on 36 of 41 patients who completed the induction chemoradiotherapy.

RESULTS

Of the 44 patients, 17 are alive at a median follow-up of 50 months. Of these 17 patients, 15 show no evidence of recurrent disease. Of the 14 patients with long-term survival (> or =3 years), 1 patient died of disease, and another patient is alive with disease. The remaining 12 patients are alive and disease-free (median follow-up, 54 months). Six patients have survived longer than 4 years and 3 patients longer than 5 years. Subsequent primary tumors have developed in 2 patients. One patient had a recurrence at 11 months following initiation of treatment and remains disease-free 43 months postresection of a single brain metastasis. Standard clinicopathologic parameters (age, sex, histologic findings, chemoradiotherapy regimen, and clinical and pathologic stages) were not significantly associated with a survival time of 3 years or longer (Fisher exact test, 2-tailed). Although not significant, p 53 mutational status suggested long-term survival. In 11 of 14 patients who are alive with no history of recurrence, p53 genotyping demonstrated no point mutations in 10 patients. Median survival time for the long-term survivors has not been reached.

CONCLUSIONS

Long-term survival can be achieved in patients with esophageal carcinoma who undergo induction chemoradiotherapy and esophagectomy. Recurrence is unlikely in patients who survive for 3 years or longer after undergoing this multimodality treatment.