The challenges with NOTES retroperitoneal access in humans.

BACKGROUND: Animal studies have supported natural orifice transluminal endoscopic surgery (NOTES) retroperitoneal access. NOTES also may offer unique retroperitoneal access in humans. OBJECTIVES: This study was designed to assess the feasibility of endoscopic transgastric and transrectal retroperitoneal access in a cadaver model using prone and supine positioning, and to compare NOTES retroperitoneal examination with endoscopic ultrasound. METHODS: Using a multidisciplinary team, this institutional review board-approved study evaluated transgastric and transrectal retroperitoneal examination in six cadavers (3 male, 3 female; body mass index range, 25-37 kg/m(2)). Endoscopic ultrasound retroperitoneal examination preceded NOTES access. Transgastric Access: Using a prototype dual channel endoscope, a needle knife gastrotomy was created on the preantral posterior gastric wall. Retroperitoneal examination specifically targeted the pancreas and surrounding structures with the cadaver supine and prone. Transrectal Access: Using the same endoscope, a posterior needle knife rectotomy distal to the upper valve of Houston provided extraluminal access. Retroperitoneal examination proceeded with the cadaver prone and supine. Open dissection followed procedure completion. RESULTS: Access into the retroperitoneum succeeded at all sites. Significant challenges locating identifiable landmarks were faced-mostly transrectal and improved transgastric prone. All cadavers, despite body mass index or sex, had significant retroperitoneal adipose tissue limiting the endoscopic view. CONCLUSIONS: Although porcine studies have highlighted successful NOTES retroperitoneal procedures, the abundant human retroperitoneal adipose tissue challenged the translation of porcine research to humans. Additionally, although access to the retroperitoneal space and dissection within this space were accomplished easily, the appearance of cadaveric tissue and lack of blood flow made confident landmark identification impossible. Further study should continue in this area and focus on confident landmark identification for directed dissection. In a cadaveric model, this would best be improved by pre-NOTES anatomic marking or active perfusion of vasculature along with consideration of direct entry into the retroperitoneum from a targeted intraperitoneal site in clinical patients.

Endoscopic retrograde cholangiopancreatography using a single-balloon enteroscope in patients with altered Roux-en-Y anatomy.

BACKGROUND AND STUDY AIMS: Endoscopic retrograde cholangiopancreatography (ERCP) is challenging to perform in patients with postsurgical gastrointestinal anatomy. We assessed the diagnostic and therapeutic success rates using single-balloon enteroscopy in patients with Roux-en-Y anastomosis. PATIENTS AND METHODS: Patients who underwent single-balloon ERCP between April 2008 and February 2010 were retrospectively identified using a computerized endoscopy database. Diagnostic success was defined as successful duct cannulation or securing the diagnosis, and therapeutic success was defined as the ability to successfully carry out endoscopic therapy. Complications of ERCP were defined according to standard criteria. RESULTS: A total of 50 patients (34-male, mean age 57 years, range 19 - 85 years) with Roux-en-Y anastomosis underwent ERCP using a single-balloon enteroscope on 56 occasions. Indications for ERCP were cholestasis, acute cholangitis, recurrent primary sclerosing cholangitis with strictures, and choledocholithiasis. Overall diagnostic success was achieved in 39 / 56 cases (70 %). Therapeutic success was achieved in 21/23 cases (91 %). In 16 cases therapeutic intervention was not required. Therapeutic interventions included balloon dilation of strictures (n = 14), retrieval of retained biliopancreatic stents (n = 5), biliary stone extraction (n = 2), insertion of biliopancreatic stents (n = 4), and biliary and pancreatic sphincterotomy (n = 5). No major complications occurred. Importantly, in 22 / 56 procedures (39 %) a prior attempt at ERCP failed using conventional colonoscopes; single-balloon ERCP was successful in 15 / 22 (68 %) of these cases. CONCLUSIONS: Single-balloon ERCP is feasible in patients with complex postsurgical Roux-en-Y anastomosis, allows diagnostic evaluation and therapeutic intervention in patients with pancreaticobiliary disease, and is a useful salvage technique in the majority of patients in whom ERCP using colonoscopies has failed.

The role of endoscopic ultrasound for loco-regional staging of rectal cancer.

Rectal cancer is projected to have the 10th highest incidence of cancer in the United States in 2009, with 40 870 estimated new cases this year. The prognosis for patients with rectal cancer is directly related to several factors, with the most important, based on current data, the extent of primary tumor invasion, the number of lymph nodes involved, involvement of the circumferential resection margin, and the presence of metastases. Contemporary therapy is dependent upon pre-surgical diagnostic imaging modalities, which influence the indication for neoadjuvant therapy and the decision process concerning the appropriate surgical approach. A comprehensive overview based on the currently available evidence of endoscopic ultrasound imaging in the loco-regional assessment of primary de novo rectal cancer evaluation following neoadjuvant therapy and post operative disease surveillance is presented. Relevant ano-rectal anatomy, staging systems for rectal cancer and alternative radiological staging strategies are also presented.

Risk of pancreatitis following endoscopically placed large-bore plastic biliary stents with and without biliary sphincterotomy for management of postoperative bile leaks.

BACKGROUND: Endoscopic transpapillary biliary stent placement is effective for closure of postoperative bile leaks. Large-bore stents (10 French) may transiently obstruct the adjacent pancreatic duct orifice causing acute pancreatitis. Endoscopic biliary sphincterotomy may reduce this risk, but it introduces separate risks of bleeding and perforation. The objective of this study was to compare complications after large-bore biliary stent placement (10 Fr) with and without sphincterotomy in patients with bile leaks. METHODS: The institutional endoscopy database was queried to identify patients who had undergone endoscopic retrograde cholangiopancreatogrpahy (ERCP) for bile leak between March 1996 and August 2006. Procedural reports were reviewed for evidence of biliary sphincterotomy, cholangiographic and pancreatographic findings, transpapillary stent placement, and procedural complications. Patients with prior biliary sphincterotomy, choledochoenteric anastomosis, placement of multiple biliary stents and expandable metal biliary stents, biliary stents smaller than 10 Fr, and patients in whom a stent was not placed were excluded. The chi-square test was used for categorical variables. Probability

Endoscopic ultrasound (EUS) guided access and therapy of pancreatico-biliary disorders.

Endoscopic ultrasound (EUS) has evolved from a purely diagnostic imaging modality to one that allows therapeutic intervention. It now serves as a viable alternative, and at times is preferred, to percutaneous and surgical techniques for obtaining biliary and pancreatic duct access and for providing drainage. EUS guided intervention is usually performed following failed endoscopic retrograde cholangiopancreatography (ERCP) or as an option for patients who decline surgical intervention or in poor operative candidates. Published data demonstrate overall technical success in 83% of patients with 12% experiencing a procedure related complication. New techniques and equipment must be developed to simplify and abbreviate the procedures, to limit complications, and improve outcomes. In addition, longitudinal data are needed to determine the long-term outcomes and role of EUS guided pancreaticobiliary intervention.

Endoscopic transpapillary gallbladder drainage: 10-year single center experience.

AIM: A subset of patients with acute cholecystitis is severely ill and extremely high-risk to undergo cholecystectomy. Data on the use of endoscopic transpapillary gallbladder drainage (ETGBD) in the treatment of acute cholecystitis are limited. This article reviews the 10-year experience of ETGBD at Mayo Clinic and evaluated patient and procedure characteristics. METHODS: A retrospective review of the endoscopy database from 1998-2007 was performed to identify patients who had undergone ETGBD. Clinical information and procedure details were abstracted from the electronic medical record. RESULTS: Fifty one patients underwent ETGBD for acute cholecystitis between 1998 to July 2007. The mean age was 62+/-19 years and 67% of patients were males. The median number of comorbid medical conditions was two (range 0-5) and 27% had underlying diabetes mellitus. Acute calculous cholecystitis was the predominant indication for ETGBD (78%). A gallbladder stent was used in 33 (65%) patients, nasocholecystic drain in 14 (27%) patients, and both in four patients (8%). Bleeding (4%) and sedation-related complications (4%) were the most common complications noted. Among patients who underwent cholecystectomy, the majority (76%) needed an open procedure. The median time to cholecystectomy was 15 days (range 1-352 days). Four patients (8%) succumbed to septic shock during their hospitalization. CONCLUSIONS: ETGBD is a valuable alternative therapeutic modality for the treatment of patients with acute cholecystitis who are at high-risk for early cholecystectomy, and/or those who have contraindications to percutaneous gallbladder drainage.

SOCIETY FOR ENDOCRINOLOGY CLINICAL GUIDANCE: Inpatient management of cranial diabetes insipidus.

Cranial diabetes insipidus (CDI) is a treatable chronic condition that can potentially develop into a life-threatening medical emergency. CDI is due to the relative or absolute lack of the posterior pituitary hormone vasopressin (AVP), also known as anti-diuretic hormone. AVP deficiency results in uncontrolled diuresis. Complete deficiency can lead to polyuria exceeding 10 L/24 h. Given a functioning thirst mechanism and free access to water, patients with CDI can normally maintain adequate fluid balance through increased drinking. Desmopressin (DDAVP, a synthetic AVP analogue) reduces uncontrolled water excretion in CDI and is commonly used in treatment. Critically, loss of thirst perception (through primary pathology or reduced consciousness) or limited access to water (through non-availability, disability or inter-current illness) in a patient with CDI can lead to life-threatening dehydration. This position can be further exacerbated through the omission of DDAVP. Recent data have highlighted serious adverse events (including deaths) in patients with CDI. These adverse outcomes and deaths have occurred through a combination of lack of knowledge and treatment failures by health professionals. Here, with our guideline, we recommend treatment pathways for patients with known CDI admitted to hospital. Following these guidelines is essential for the safe management of patients with CDI.

Frequency of visualization of presumed celiac ganglia by endoscopic ultrasound.

BACKGROUND AND STUDY AIMS: Celiac ganglia can be visualized by endoscopic ultrasound (EUS). It is unknown how often ganglia are visualized during EUS, and what clinical factors are associated with ganglion visualization. The aim of this study was to prospectively evaluate the frequency of visualization of presumed celiac ganglia by EUS and to identify factors that predict their visualization. PATIENTS AND METHODS: Clinical, demographic, EUS, and cytologic data were collected prospectively from 200 unselected patients who were undergoing EUS in a tertiary referral centre. When presumed celiac ganglia were visualized, their size, number, location, and echo features were noted. When presumed ganglia were aspirated, the results of cytology were recorded. RESULTS: The most common indication for EUS was investigation of a pancreatic mass or cyst (25 %). Presumed celiac ganglia were identified in 81 % of patients overall. Logistic regression analysis determined that female sex and having no prior history of gastrointestinal surgery were independently associated with ganglion visualization. Among patients whose ganglia were visualized, more ganglia were seen per patient with linear echo endoscopes (2, range 0 - 5) than with radial echo endoscopes (1, range 0 - 4) ( P = 0.001). Presumed celiac ganglia were aspirated in 10 patients; and cytologic examination revealed neural ganglia in all of these. CONCLUSIONS: Celiac ganglia can be visualized by EUS in most patients who undergo upper gastrointestinal EUS examinations, and are best seen with linear-array echo endoscopes. Ganglia can usually be differentiated from lymph nodes on the basis of their endosonographic appearance.

Pancreatic stent prophylaxis of post endoscopic retrograde cholangiopancreatography pancreatitis: spontaneous migration rates and clinical outcomes.

AIM: Pancreatic duct (PD) stents diminish the risk of post endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) in high-risk patients; 3 Fr stents are reported to spontaneously migrate at a significantly higher rate than 5 Fr stents in a cohort of mostly sphincter of Oddi (SOD) patients. We sought to assess spontaneous migration rates of 5 Fr and 7 Fr stents and effectiveness in preventing PEP in a diverse group of high risk patients. METHODS: A total of 4,332 ERCP exams performed between January 2002 and August 2005 were reviewed to identify patients undergoing PD stent placement. Follow-up was obtained from electronic medical records and contact with referring MDs. Plain abdominal radiographs were used to document stent passage. RESULTS: PD stents for PEP prophylaxis were placed in 246 exams (232 patients) undergoing: PD (major or minor) sphincterotomy (84), ampullectomy (50), SOD (46), bile duct precut (35), papillary stenosis balloon dilation (9) and difficult cannulation (8). Stents placed: 218 5-Fr (140 were 3 cm long and 78 =or> 5 cm long) and 28 7-Fr (12 were 3 cm long, 16=or> 5cm long). Follow-up was available in 197 (171 5-Fr, 26 7-Fr) of 246 placements (80%). Twenty of 171 5-Fr stents were electively removed via EGD within=or< 24 h per endoscopist preference and were not included in analysis; 128 of the remaining 151 5-Fr stents (85%) spontaneously migrated by (or within) median of 8 days and 23 failed to pass and required EGD removal. Of 26 7-Fr stents one was electively removed =or< 24 h later; of the remaining 25, 15 (60%) spontaneously migrated by median of 16 days, 10 required EGD removal. The spontaneous migration rate of 5 Fr stents was: 1) significantly higher than 7 Fr stents; 2) significantly higher than the previously reported 67% passage rate of 5 Fr stents; and 3) similar to the previously reported 86% passage rate of 3 Fr stents. PEP occurred in 15% (n=36: 24 mild, 11 moderate, 1 severe). CONCLUSION: The spontaneous dislodgement rate of 5 Fr stents in patients where the indication is primarily non-SOD is approximately 85% - significantly higher than previously reported and similar to the reported rate of spontaneous dislodgement of 3 Fr stents in SOD patients; 5 Fr stents migrate spontaneously earlier and more frequently than 7 Fr stents.

The clinical characteristics of headache in patients with pituitary tumours.

The clinical characteristics of 84 patients with pituitary tumour who had troublesome headache were investigated. The patients presented with chronic (46%) and episodic (30%) migraine, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT; 5%), cluster headache (4%), hemicrania continua (1%) and primary stabbing headache (27%). It was not possible to classify the headache according to International Headache Society diagnostic criteria in six cases (7%). Cavernous sinus invasion was present in the minority of presentations (21%), but was present in two of three patients with cluster headache. SUNCT-like headache was only seen in patients with acromegaly and prolactinoma. Hypophysectomy improved headache in 49% and exacerbated headache in 15% of cases. Somatostatin analogues improved acromegaly-associated headache in 64% of cases, although rebound headache was described in three patients. Dopamine agonists improved headache in 25% and exacerbated headache in 21% of cases. In certain cases, severe exacerbations in headache were observed with dopamine agonists. Headache appears to be a significant problem in pituitary disease and is associated with a range of headache phenotypes. The presenting phenotype is likely to be governed by a combination of factors, including tumour activity, relationship to the cavernous sinus and patient predisposition to headache. A proposed modification of the current classification of pituitary-associated headache is given.

Inhibition of nociceptive dural input in the trigeminal nucleus caudalis by somatostatin receptor blockade in the posterior hypothalamus.

Somatostatin is a neuromodulator in the central nervous system and is involved in the regulation of metabolic and neuroendocrine functions. Recent experimental and clinical findings point to a role for somatostatin in the central processing of nociception. We studied the effects of somatostatin receptor modulation in the posterior hypothalamic area (PH) of the rat on dural nociceptive input. Somatostatin (10 microg/microl) and the somatostatin antagonist cyclo-somatostatin (50 microg/microl) were microinjected into the PH and the effects on responses of neurons in the trigeminal subnucleus caudalis studied. Injection of somatostatin (n=11) did not affect A- and C-fibre responses to dural electrical stimulation, nor was spontaneous activity altered (P>0.05). Injection of cyclo-somatostatin (n=10) into the PH reduced A-(-35.5+/-5.8%) and C-fibre (-43.1+/-7.5%) responses to dural stimulation and resulted in decreased spontaneous activity (-38.1+/-7.3%, P<0.05). Responses to facial thermal stimulation were decreased by 51.2+/-5.8% (n=5). Control injections had no significant effect (n=9). Blockade of somatostatin receptors in the PH has an anti-nociceptive effect on dural and facial input, probably mediated via GABAergic mechanisms. As somatostatin is also involved in hypothalamic regulation of metabolic, neuroendocrine and autonomic functions, somatostatin receptor mechanisms in the PH may play a role in the pathophysiology of primary headache disorders, such as migraine or cluster headache.