SAMCEP Society consensus on the treatment of upper facial lines with botulinum neurotoxin type A: A tailored approach.

BACKGROUND: The safety and efficacy of botulinum neurotoxin type A (BoNTA) treatments are well established, but injection techniques, target muscles, and toxin doses continue to evolve, with each refinement producing improvements in treatment outcomes. The recommendations in this consensus move away from standard templates and illustrate how to tailor treatments to individual patterns and strengths of muscle activity, and patient preferences. METHODS: Seventeen experts in the fields of plastic surgery, dermatology, ophthalmology, otorhinolaryngology, and neurology convened in 2022 to develop consensus-based recommendations for the use of botulinum toxin A for the treatment of horizontal forehead lines, glabellar frown lines, and crow's feet lines that reflect current clinical practice. The focus was on how to tailor injections to individual patients to optimize treatment outcomes. RESULTS: For each upper face indication, consensus members describe how to perform a dynamic assessment to optimize the dose and injection technique for each patient. A tailored treatment protocol is presented for commonly observed patterns of dynamic lines. Units of Inco are defined and the precise location of injection points, illustrated with the use of anatomical images. CONCLUSION: This consensus provides up-to-date recommendations on the tailored treatment of upper facial lines based on the latest research and collective clinical experience of the expert injectors. Optimal outcomes require thorough patient evaluation, both at rest and during animation, using both visual and tactile cues; detailed understanding of facial muscular anatomy and how opposing muscles interact; and use of a BoNTA with high precision to target identified zones of excess muscle activity.

Esophagojejunostomy after total gastrectomy for caustic injuries.

The objective of the study was to compare outcomes of emergency esophagogastrectomy (EGT) and total gastrectomy with immediate esophagojejunostomy (EJ) in patients with full-thickness caustic necrosis of the stomach and mild esophageal injuries. After caustic ingestion, optimal management of the esophageal remnant following removal of the necrotic stomach remains a matter of debate. Between 1987 and 2012, 26 patients (men 38%, median age 44 years) with isolated transmural gastric necrosis underwent EGT (n = 14) or EJ (n = 12). Early and long-term outcomes of both groups were compared. The groups were similar regarding age (P = 0.66), gender (0.24), and severity of esophageal involvement. Functional success was defined as nutritional autonomy after removal of the jejunostomy and tracheotomy tubes. Emergency morbidity (67% vs. 64%, P = 0.80), mortality (17% vs. 7%, P = 0.58), and reoperation rates (25% vs.14%, P = 0.63) were similar after EJ and EGT. One patient (8%) experienced EJ leakage. One patient in the EJ group and 13 patients in the EGT group underwent esophageal reconstruction (P < 0.0001). Aggregate in hospital length of stay was significantly longer in patients who underwent EGT (median 83 [33-201] vs. 36 [10-82] days, P = 0.001). Functional success after EJ and EGT was similar (90% vs.69%, P = 0.34). Immediate EJ can be safely performed after total gastrectomy for caustic injuries and reduces the need of further esophageal reconstruction.

Functional disorders and quality of life after esophagectomy and gastric tube reconstruction for cancer.

Functional disorders such as delayed gastric emptying, dumping syndrome or duodeno-gastro-esophageal reflux occur in half of the patients who undergo esophagectomy and gastric tube reconstruction for cancer. The potential role for pyloroplasty in the prevention of functional disorders is still debated. Antireflux fundoplication during esophagectomy can apparently reduce the reflux but at the cost of increasing the complexity of the operation; it is not widely used. The treatment of functional disorders arising after esophagectomy and gastroplasty for cancer is based mainly on dietary measures. Proton pump inhibitors have well documented efficiency and should be given routinely to prevent reflux complications. Erythromycin may prevent delayed gastric emptying, but it should be used with caution in patients with cardiovascular disorders. In the event of anastomotic stricture, endoscopic dilatation is usually efficient. Problems related to gastrointestinal functional disorders after esophageal resection and gastric tube reconstruction do not significantly impair long-term quality of life, which is mainly influenced by tumor recurrence.

Oesophagogastrectomy and pancreatoduodenectomy for caustic injury.

BACKGROUND: The justification for pancreatoduodenectomy (PD) for extended duodenal and pancreatic caustic necrosis is still a matter of debate. METHODS: This was a retrospective evaluation of patients who underwent PD in association with oesophagogastrectomy from a large single-centre cohort of patients with caustic injuries. Morbidity, mortality and long-term outcome were assessed. RESULTS: PD was performed in 18 (6·6 per cent) of 273 patients who underwent emergency surgery for caustic injuries. Biliary and pancreatic duct reconstruction during PD was performed in ten and six patients respectively. Seven patients died and 17 experienced operative complications after PD for caustic injuries. Twelve patients required at least one reoperation. Specific PD-related complications occurred in 13 patients. Initial (P = 0·038) or secondary (P < 0·001) extension of necrosis to adjacent organs were independent predictors of operative death. After a median follow-up of 24 months following reconstruction, three patients had recovered nutritional autonomy. In an intention-to-treat analysis, functional success was recorded in three patients and the 5-year survival rate was 39 per cent after PD for caustic injury. CONCLUSION: PD can save the lives of patients with caustic injuries extending beyond the pylorus, but has poor functional outcome. Immediate pancreatic duct reconstruction should be preferred to duct occlusion to decrease the rate of pancreatic complications.

Esophageal perforations.

The incidence of esophageal perforation (EP) has risen with the increasing use of endoscopic procedures, which are currently the most frequent causes of EP. Despite decades of clinical experience, innovations in surgical technique and advances in intensive care management, EP still represents a diagnostic and therapeutic challenge. EP is a devastating event and mortality hovers close to 20%. Ambiguous presentations leading to misdiagnosis and delayed treatment and the difficulties in management are responsible for the high morbidity and mortality rates. A high variety of treatment options are available ranging from observational medical therapy to radical esophagectomy. The potential role of interventional endoscopy and the use of stents for the treatment of EP seem interesting but remain to be evaluated. Surgical primary repair, with or without reinforcement, is the preferred approach in patients with EP. Prognosis is mainly determined by the cause, the location of the injury and the delay between perforation and initiation of therapy.

[Colonic interposition for esophageal replacement after caustic ingestion]. / Reconstruction oesophagienne pour séquelles de brûlure caustique: coloplasties, mode d'emploi.

Retrosternal coloplasty is the gold standard for esophageal reconstruction after caustic injury of the digestive tract. Complete preoperative otolaryngology evaluation and the control of the psychiatric disease are key factors for success. In the absence of controlled studies, the choice between the right and the left colon graft relies on the anatomy of the blood supply to the colon and on the individual surgeon's preference. Treatment of associated pharyngeal and laryngeal injuries is mandatory at the time of esophageal reconstruction. In experienced hands mortality rates are less than 5% but specific postoperative complications (graft necrosis, leakage, anastomotic stricture) are high. The low risk of cancer development in the by-passed esophagus does not justify routine esophagectomy at the time of reconstruction. Sixty to eighty percent of patients would finally retrieve nutritional autonomy after coloplasty for caustic injury. Late acquired dysfunctions of the coloplasty (anastomotic strictures, graft redundancy) requiring revision surgery occur frequently and might jeopardize an already fragile functional result. Timely diagnosis and treatment of such complications and the necessity of continuous psychological surveillance justify the need for long term follow up in these patients.

[Colonic lipoma: case report and literature review]. / Lipome colique : cas clinique et revue de la littérature.

Colonic lipoma is a rare benign tumor infrequently met in clinical practice. We report a case of symptomatic lipoma of the ascending colon in a 61-year-old woman. Diagnosis was suspected on CT scan. Colotomy with lipectomy was performed. The diagnosis was confirmed by histological examination. Reviewing the literature and combining with our experience, we discuss the clinical features, diagnosis and treatment of this uncommon disease.

[Laparoscopic partial splenectomy using the Harmonic Scalpel. Two case reports]. / Splénectomie partielle par laparoscopie et ultracision. A propos de deux cas.

For the extirpation of a benign splenic cyst, partial splenectomy is an appropriate approach, since there is significant long-term morbidity following total splenectomy. We report two cases of laparoscopic partial splenectomy for benign splenic cyst. The use of the harmonic scalpel along with segmental ligation of the splenic pedicle allowed the completion of these interventions with minimal blood loss.

A very high incidence of low 25 hydroxy-vitamin D serum concentration in a French population of patients with primary hyperparathyroidism.

Since the demonstration that vitamin D status might influence the clinical and biological expression of primary hyperparathyroidism (PHPT), a serum 25-hydroxy vitamin D (25-OHD) concentration of 50 nmol/l has been considered by an expert panel as the minimum level to be maintained in asymptomatic PHPT patients. Two yr after this recommendation, we aimed to evaluate the frequency of serum 25-OHD concentrations below this threshold in PHPT patients. In the present study, serum 25-OHD, second- and third-generation PTH, calcium, phosphate, magnesium, albumin and creatinine were measured in 72 out 145 consecutive PHPT patients operated on in our Endocrine Surgery Department, in whom blood samples were available before as well as two days after surgical intervention. Before surgery, the frequency of serum 25-OHD levels <50 nmol/l ranged from 91.5 to 100% whatever the classification used to identify patients: whole group, symptomatic vs asymptomatic, patients with calcium levels >3 vs <3 mmol/l. 25-OHD concentrations correlated negatively with the weight of adenoma, PTH levels, and total calcium concentrations measured before surgery. Pre-operative PTH levels, whatever the assay used, and total calcium concentrations were positively and significantly correlated. Two days post-surgery, 13 patients were moderately hypocalcemic. Neither pre-surgery 25-OHD nor PTH, calcium or phosphorus level or adenoma weight were predictive of post-operative hypocalcemia. The dramatic frequency of low 25-OHD concentrations in our PHPT patients demonstrates that the above-mentioned recommendation is far from being applied in France despite evidence of worsening expression of PHPT with decreasing 25-OHD serum levels.

[Minimally invasive esophagectomy: prospective evaluation of laparoscopic gastric mobilization]. / Oesophagectomie mini-invasive: évaluation prospective de la gastrolyse coelioscopique.

OBJECTIVE: Esophagectomy carries high morbidity, mainly due to respiratory complications. In digestive surgery, postoperative outcome is generally improved by minimally invasive surgery. A prospective study was conducted to evaluate feasibility and postoperative outcome of minimally invasive esophagectomy (MIE). METHODS: From July 2001 to June 2004, 20 patients underwent esophagectomy with laparoscopic gastric mobilization (LGM) for squamous cell carcinoma (N=11), adenocarcinoma (N=7), Barrett's esophagus with high-grade dysplasia (N=1), and long peptic stricture (N=1). Tumours (N=19) were located on the cardia (N=5), on the lower third of the oesophagus (N=10), on the median third (N=3), and on the upper third (N=1). Following LGM, transthoracic (N=19) or transhiatal (N=1) oesophagectomy was performed. RESULTS: Complete LGM was achieved in all cases. Mean operative time for LGM was 197+/-48 minutes. In the 19 patients operated for tumours, 18 underwent R0 resection. Eleven patients (55%) developed postoperative complications, mainly (30%) respiratory. Intrathoracic anastomotic leakage occurred in 2 patients, with favourable outcome. Pylorospasm (N=1) was the only intraabdominal complication. One patient died (5%). CONCLUSION: Esophagectomy with LGM is feasible with few specific complications. However, no decrease in morbidity could be observed with this technique. Further studies are required to evaluate if thoracoscopy could improve the postoperative course after LGM and to validate oncologic safety of MIE.

[Gastrinomas in multiple endocrine neoplasia type-1. A 127-case cohort study from the endocrine tumor group (ETG)]. / Les gastrinomes dans les néoplasies endocriniennes multiples de type 1. Une étude de cohorte de 127 cas du groupe des tumeurs endocrines (GTE).

UNLABELLED: On July 2000, 127 gastrinomas (31.1%) were studied by the Endocrine Tumour Group (GTE) using a 408-patient cohort of Multiple Endocrine Neoplasia Type 1 patients. The aim of this study was to assess clinical, biological, surgical data as well as their trends over three periods (<1980-1980/1989->1990). A Zollinger-Ellison syndrome (SZE) was present in 96% of the cases. Mean age at the onset of the disease was 39.4 years. There were 55.9% of men. Synchronous liver metastasis was present in 7.1%. Taken independently, the positivity of the four main diagnosis tests decreased over the time. The diagnosis of oesophagitis increased (4.5-29.7%), as well as the size of the resected tumours (9.9-16.8 mm). There was an increase in the familial background diagnosis (73.1-80%), an increasing use of Octreoscan scintigraphy and transduodenal ultrasound with positive detection of metastasis and tumours in 81.3% and 92.3%, respectively after 1991. Patients were operated on less frequently (96-52.5%), less frequently from the pancreas (87.5-37.5%), and from the gastro-intestinal tract (70.8-30%). The relative percentage of major pancreatic resections increased (with at least removal of the duodenum and the pancreatic head) (10-26.7%). The operative mortality disappeared. Six out of the seven patients (85.7%) who benefited from major pancreatic resections normalized their gastrine level postoperatively versus 15% in less radical techniques. Overall 5 years survival was 90 +/- 4.4%. Survival increased after 1985 (85 +/- 4.8% versus 95 +/- 3.6, P = 0.1). CONCLUSION: SZE in NEM1 were diagnosed at an earlier stage and were less frequently operated on. Nevertheless, the incidence of synchronous metastasis did not change significantly. Patients were mainly operated on for gastric emergencies and pancreatic tumours in order to prevent metastasis without mortality after 1991.

[Multiple endocrine neoplasia type I or Werner syndrome. What is important to know about surgery of a rate disease]. / La néoplasie endocrinienne multiple de type 1 ou syndrome de Wermer. Ce qu'il faut savoir en chirurgie d'une maladie rare.

Multiple endocrine neoplasia type 1 (MEN1) is a rare but misleading disease. The diagnosis is evocated when two main lesions are present (parathyroid, endocrine pancreas, pituary gland) but also when a family tree shows recurrent lesions. Other lesions must be taken into account (adrenal glands, neuroendocrine thymic or bronchic lesions, cutaneous lesions, lipomas, nervous central system tumors). Any surgical cure without knowing the MEN1 background leads to failure. Specific treatment of each lesion is reviewed. Genetic diagnosis is possible but the mutation is not found in all cases. Nevertheless, when the mutation is known in a family, a negative genetic test allows to exclude the disease. Prognosis is related to hepatic metastases and to thymic neuroendocrine tumors which are rare (2.1%) but aggressive. As a general rule, any apparently isolated endocrine lesion such hyperparathyroidism must prompt the surgeon to look for another endocrine lesion and to look for an abnormal family tree with recurent monoglandular or pluriglandular lesions.

Bradykinin-induced neuropeptide Y release by human pheochromocytoma tissue.

Neuropeptide Y (NPY) and noradrenaline (NA) are frequently co-localized and co-released in the sympathetic nervous system. Since bradykinin (BK) is known to stimulate neurotransmitter release as NA in adrenal glands, we therefore hypothesized that BK might also be involved in the release of NPY. The effect of BK(1-9) on immunoreactive NPY (Ir-NPY) release was investigated in superfused human pheochromocytoma tissue. BK(1-9) (10(-7)-10(-5) M) was shown to induce a rapid Ir-NPY release in a concentration-dependent manner. This effect of BK(1-9) (10(-6) M) was mimicked by the B2 agonist [Phe(8)(CH(2)NH)Arg(9)]-bradykinin (10(-5) M) and blocked by the selective B2-receptor antagonist HOE140 (10(-5) M). Increasing Ir-NPY release was probably not mediated by nitric oxide (NO) since the outflow of Ir-NPY was not influenced by the NO synthase inhibitor N-omega-nitro-L-arginine methyl ester (L-NAME) (10(-4) M). In presence of bapta-AM (10(-5) M), a chelator of cytosolic calcium, W7 (10(-5) M), a calmodulin inhibitor, TMB-8 (10(-5) M), a blocker of intracellular calcium mobilization and ryanodine (10(-5) M), a selective inhibitor of the Ca(2+)-induced release mechanism, the NPY release by BK(1-9) was significantly inhibited by 126%, 98%, 91%, and 94%, respectively. These results indicate that BK increased the release of NPY by the tumor acting through the interaction with the BK-B2 receptor and request intracellular calcium mobilization independently of a NO mechanism.

Fate of the rectum in patients undergoing total colectomy for Crohn's disease.

BACKGROUND: This study aimed to analyse disease recurrence and fate of the rectum in patients who had a total colectomy for Crohn's disease. METHODS: One hundred and forty-four patients who had a total colectomy for Crohn's colitis were reviewed retrospectively. Ileorectal anastomosis (IRA) was performed in 118 patients, while 26 never had an IRA after colectomy because of severe anorectal lesions. Factors associated with recurrence and rectal preservation failure were studied. RESULTS: The probability of clinical recurrence after IRA was 58 and 83 per cent at 5 and 10 years respectively. The probability of rectal preservation at 5 and 10 years was 70 and 63 per cent after colectomy, and 86 and 86 per cent after IRA, respectively. Patients with extraintestinal manifestation had a higher risk of recurrence and of rectal preservation failure. Previous ileal involvement was associated with a higher rate of ileal recurrence after IRA. After IRA, prophylactic treatment with 5-aminosalicylic acid was associated with a lower rate of recurrence and of failure to preserve the rectum. CONCLUSION: Overall, 63 per cent of patients had a functioning IRA 10 years after total colectomy. Absence of extraintestinal manifestation and prophylactic treatment with 5-aminosalicylates after IRA were the main factors associated with long-term rectal preservation.

Impact on survival of surgery after concomitant chemoradiotherapy for locally advanced cancers of the esophagus.

BACKGROUND: To evaluate the results of chemoradiotherapy with or without surgery in locally-advanced esophageal carcinomas (T3 and/or nodal involvement). METHODS: One hundred twelve patients with locally-advanced carcinoma of the esophagus without histologically proven invasion of the tracheobronchial tree or distant visceral metastases were treated with concomitant chemoradiotherapy followed by re-evaluation; surgery was performed or chemoradiotherapy continued, based on tumor regression and the patient's general status. Chemoradiotherapy consisted of concomitant 5-fluorouracil (5FU)(1 g/m(2) day 1-3), cisplatinum (50 mg/m(2) day 1 and 2), and external beam irradiation up to a dose of 40 or 43.2 Gy. After a 4-week rest period, radical esophagectomy or a new cycle of chemoradiotherapy (up to a total dose of 65 Gy) was performed. RESULTS: A complete clinical response was obtained in 25.7% of the patients and a partial response in 45.9%. Fifty patients underwent surgery, but only 38 patients had an esophagectomy. Post-esophagectomy mortality was 5.3%. A complete histologic response rate of 23.7% was obtained. Two- and 5-year survival rates were, respectively, 41.5% and 28.6% for the whole population. According to multivariate analysis, prognostic factors for survival were Karnofsky index, esophagectomy, and response to chemoradiotherapy. Five-year survival for patients who experienced a partial response to radiation and chemotherapy was 49.1% for those who had surgery and 23.5% for those treated without surgery (p = 0.003). There was no obvious benefit for the small number of patients treated surgically after complete response to radiation and chemotherapy. Toxicity, essentially hematologic, was moderate. CONCLUSION: For locally-advanced esophageal carcinomas, esophagectomy, after concomitant chemoradiotherapy, could improve the survival rate, especially for patients who responded partially to the latter.

[Insulinomas in multiple endocrine neoplasia type 1. Report of a series of 44 cases by the multiple endocrine neoplasia study group]. / Les insulinomes dans les néoplasies endocriniennes multiples de type 1 (NEM1). A propos d'une série de 44 cas du groupe d'étude des néoplasies endocriniennes multiples (GENEM).

STUDY AIM: The aim of this retrospective study conducted by the "Groupe d'étude des néoplasies endocriniennes multiples type 1" (GENEM) was to report a series of insulinomas associated with multiple endocrine neoplasias type 1 (NEM 1) and to determine the most appropriate strategy for the topographical exploration and surgical management. PATIENTS AND METHODS: From 1960 to 1996, 44 patients were included, 16 men and 28 women (mean age: 36.4 +/- 13.9 years). This study concerned morphological investigations, tumoral features, modalities and results of the treatment. RESULTS: Insulinomas were associated with other functional islet tumors in 15 patients: ZE syndrome (n = 8), glucagonoma (n = 6), vipoma (n = 1). Malignant lesions were present in 6 patients: isolated insulinomas (n = 2), insulinomas associated with ZE syndrome (n = 2) and vipoma (n = 1). The sensitivity of the preoperative imaging procedures was less than 70%. Fourty-one patients were operated on: subtotal pancreatectomy (n = 26 including cephalic enucleations in 8), enucleations (n = 8), total pancreatectomy (n = 3), pancreaticoduodenectomy with caudal enucleations (n = 1), and for 3 patients, no details were available. There was no postoperative mortality. Hyperinsulinism disappeared in 27 patients (including 2 after reoperation) with a mean follow-up of 9 years. Among 6 patients with malignant lesions, 3 were alive with a 3, 4 and 10 year-follow-up. CONCLUSION: Subtotal pancreatectomy with splenic conservation and enucleation of cephalic lesions is suggested as the procedure of choice in this group of patients. This procedure allows simplification of preoperative imaging investigations because lesions of the pancreatic head have only to be detected. Preoperative endoscopic ultrasonography and intraoperative ultrasonography are the best investigations.

Reoperation for secondary uremic hyperparathyroidism: are technical difficulties influenced by initial surgical procedure?

BACKGROUND: Parathyroid surgery in patients with uremia and secondary hyperparathyroidism is performed either by subtotal parathyroidectomy or total parathyroidectomy with immediate reimplantation. The aim of this study was to compare the results of reoperation for persistent or recurrent hyperparathyroidism after parathyroidectomy according to which initial operative procedure was used. PATIENTS AND METHODS: Eighty-nine patients had reoperation for persistent (28 patients) or recurrent (61 patients) hyperparathyroidism after 53 subtotal parathyroidectomies and 36 total parathyroidectomies with immediate reimplantation. Results of the reoperation were assessed in terms of success rate, morbidity, and operative findings. RESULTS: The success rate of reoperation in patients with persistent hyperparathyroidism was 89% and was independent of the initial type of surgery. Success rates of reoperation for recurrent hyperparathyroidism after initial subtotal parathyroidectomy and total parathyroidectomy with immediate reimplantation were 87% and 70%, respectively (P = .02). Hypertrophy of the parathyroid remnant was the main cause of recurrence after subtotal parathyroidectomy. After total parathyroidectomy with immediate reimplantation, recurrence was located in the graft in half the patients, while hyperplastic tissue was found in the neck or the mediastinum in the other half. CONCLUSIONS: Subtotal parathyroidectomy provides the best conditions for successful reoperation in case of recurrent hyperparathyroidism and should become the surgical treatment of choice for secondary hyperparathyroidism.

Extensive abdominal surgery after caustic ingestion.

OBJECTIVE: To report the authors' experience in extensive abdominal surgery after caustic ingestion, and to clarify its indications. SUMMARY BACKGROUND DATA: After caustic ingestion, extension of corrosive injuries beyond the esophagus and stomach to the duodenum, jejunum, or adjacent abdominal organs is an uncommon but severe complication. The limit to which resection of the damaged organs can be reasonably performed is not clearly defined. METHODS: From 1988 to 1997, nine patients underwent esophagogastrectomy extended to the colon (n = 2), the small bowel (n = 2), the duodenopancreas (n = 4), the tail of the pancreas (n = 1), or the spleen (n = 1). Outcome was evaluated in terms of complications, death, and function after esophageal reconstruction. RESULTS: Five patients required reintervention in the postoperative period for extension of the caustic lesions. There were two postoperative deaths. Seven patients had secondary esophageal reconstruction 4 to 8 months (median 6 months) after initial resection. Three additional patients died 8, 24, and 32 months after the initial resection. Three survivors eat normally, and one has unexplained dysphagia. CONCLUSIONS: An aggressive surgical approach allows successful initial treatment of extended caustic injuries. Early surgical treatment is essential to improve the prognosis in these patients.

Release of neuropeptide Y and hemodynamic changes during surgical removal of human pheochromocytomas.

This study investigates the release of Neuropeptide Y from eight human pheochromocytomas. Profil immunoreactive Neuropeptide Y (Ir-NPY) levels during the management of surgery were compared with these of norepinephrine (NE) while hemodynamics were monitored. Plasma IrNPY and NE levels increased during tumor manipulation and returned to near normal one hour after operation. However, Ir-NPY levels remained high just after tumor resection while NE levels were significantly decreased. At tumor manipulation and just after tumor resection, plasma Ir-NPY levels were correlated with the systemic vascular resistances (SVR) (r = 0.74; P<0.04 and r = 0.86; P<0.006 respectively). No correlation was found either between plasma Ir-NPY and NE levels or between plasma NE levels and SVR. The release of Ir-NPY from tumor tissue, studied by a superfusion method, exhibited a significant correlation with the plasma Ir-NPY concentrations at the time of corresponding tumor resection (r = 0.95; P<0.007). Chromatographic analysis showed that Ir-NPY in plasma and outflow migrate as human NPY (1-36). These results confirmed that in pheochromocytoma, plasma NPY mainly originates from the tumor and argue for an important role of NPY in pheochromocytoma hypertension as indicated by the correlation between the Ir-NPY levels and the SVR.