Does Laparoscopic Gastric Banding Demand Sophisticated Measurement Devices?

Background: One of the most frequently discussed issues in gastric banding is the problem of intraoperative upper gastric pouch volume assessment and the calibration of the connecting stoma diameter. Having experience with more than 200 adjustable and non-adjustable laparoscopic gastric bandings in last 3 years, we started to study whether it is possible to assess the pouch volume and stoma diameter by relying on anatomical landmarks and simple bougie calibration, rather than on sophisticated measuring devices. Methods: We compared results of postoperative pouch volume control measurements in a group of patients in whom a balloon method of pouch volume measurement was performed during the gastric banding with a group of patients where no intraoperative measurements of the upper gastric pouch were done. In the latter group the pouch volume was assessed according to the anatomical landmarks during the dissection: the cardia at the lesser curvature and the avascular area of gastrophrenic ligament at the greater curvature. In both groups endoscopic study 2 weeks following surgery was performed. Concerning stoma diameter we started with a prospective randomized study of two groups. In the first group, we intraoperatively measured by monometry the insidestoma pressure. In the second group, a simple bougie calibration was used, and a space was left for the tip ofthe Endo-Babcock instrument between the stomach wall and the band. Postoperatively, the stoma diameters were compared, using the ‘balloon catheter pulled through the stoma’ method. Results: Pouch volume: in the group operated according to surgeon's assessment of the anatomical landmarks, 96% of the patients' pouch volume did not exceed 60 ml at 2 weeks postoperative check-up. The results were no different from the group of patients where intraoperative volume measurements were performed. The stoma diameter: a group of patients where intraoperative stoma pressure measurements were performed and a second group where a simple calibration bougie was used and a free space for the tip of the Endo-Babcock instrument was left between stomach wall and band were compared prospectively. There was no statistical difference between the two groups in stoma diameter measured 2 weeks after operation by the ‘balloon pull through’ method. Conclusions: It is possible to rely on anatomical landmarks in constructing the upper gastric pouch. Postoperative volume measurements did not show any statistical difference between the group in whom intraoperative pouch volume measurements were performed and the group where anatomical landmarks were used. There was no statistical difference in postoperative stoma diameter measurements between the group where intraoperative stoma pressure measurements were performed before closing the band and the group where just a calibration bougie was used and a free space for the tip of an endoscopic instrument was left between stomach wall and band. These measurements were made with the non-adjustable band. With the adjustable band, the stoma diameter measurements would be even less important.     

Early short segment left colon interposition for esophageal atresia

Colon Interposition is frequently used for correction of esophageal atresia. The use of both retrosternal right colon^1–5 and transthoracic left or transverse colon^2,6–10 has been recommended. Retrosternal right colon interposition may be complicated by break downs and/or stricture of the anastomosis between cervical pharyngo-esophagus and the proximal interposed colon;^3–5,9 by vascular compromise and ischemia of the colon segment;^2,5 and by peptic ulceration of the distal interposed colon where it is anastomosed to the stomach.¹¹ Long-segment transthoracic left colon interposition may be attended by the first two complications as well;¹⁰ utilization of the esophageal stump for the distal colo-esophageal anastomosis in this technique may prevent gastroesophgeal reflux.^8–10,12Because of these problems, other methods of treatment have been suggested. The use of a gastric tube as esophageal replacement has been recommended;^13–15 however, peptic ulceration of the gastric esophagus may result.¹⁶ Elongation of the upper and, sometimes, the lower esophageal pouch with delayed primary anastomosis has been advocated.^17–19 Anastomotic leaks and/or stricture frequently accompany this procedure.Short-segment transthoracic left colon interpositions for esophageal stricture or varices have been attended by relatively fewer complications.^6–8 Therefore, a modified procedure was adopted for wide-gap esophageal atresia in 1968. A short segment of left colon was interposed transthoracically between the distal esophageal stump and proximal esophageal pouch in two infants after several weeks of bougienage had stretched the proximal pouch well below the aortic arch, so that a colo-esophageal anastomosis could be accomplished within the thorax without difficulty.     

Laparoscopic anterior gastroplasty

Background: The treatment of the morbidly obese patient is difficult because compliance with dietary regimens is poor. As a result, most weight reduction programs fail very quickly. Surgical treatment, on the other hand, provides a reliable method for sustained weight reduction. The most frequently performed procedure has been the vertical banded gastroplasty. Adaptation of the standard open procedure to laparoscopic techniques has been technically difficult and imprecise. We have developed, in the laboratory, an anterior wall banded gastroplasty that can be performed precisely and reproducibly using laparoscopic techniques. Methods: Five Yorkshire pigs were used in attempt to laparoscopically perform the standard vertical banded gastroplasty. The procedure was difficult and was associated with a risk of staple line leak and with bleeding along the lesser curvature of the stomach. Furthermore, a reproducible pouch of proper dimension could not be created reliably. Fifteen animals were then used to develop a new technique using a small gastric pouch based on the anterior gastric wall. Results: A reproducible pouch, 4 cm in length, was created over an 18-Fr nasogastric tube. A standard polyproylene band of 5.2 cm in length was utilized at the gastric pouch outlet. Conclusions: This operation can be reproduced accurately and has not demonstrated any leaks on postmortem examination. Received: 14 July 1997/Accepted: 4 February 1998     

The Technical Approach in Banding to Avoid Pouch Dilation

Background: Adjustable gastric banding results in good weight loss. Nevertheless, some complications may occur, including slipping of the stomach through the band with pouch dilatation. Initially, the Belachew and Cadière technique was done with the Lap-band^?. Afterwards, to minimize proximal gastric pouch dilatation (GPD), we performed the operation using the Swedish route with the same band (Inamed). Methods: In a retrospective study,139 consecutive adjustable gastric bands were placed laparoscopically between December 1994 and March 2000. Mean age was 37 years. 10.3% were male. Mean BMI was 39.7. Until April 1999 (Group I, n=104), the band was introduced according to Belachew's and Cadière's technique (intragastric balloon calibration technique). Starting May 1999 (Group II, n=35), the Lap-band^? was introduced using the Swedish route.This technique consists of localizing the right and left crus posteriorly. A tunnel is created behind the cardia and right above the crus after transsection of the gastrophrenic ligament. The Lap-band^? is introduced as well as an anterior intragastric calibrating balloon with an air chamber at its distal end, making a pouch 5 to 10 cc. Results: In group I, 15.4% had GPD needing rehospitalization. Of these, 75% required a re-operation. In group II, no slipping nor pouch dilatation has been reported so far. Conclusion: The Swedish route appears to be the key to avoiding GPD. By introducing an intragastric calibrating balloon with a pouch of 5 to 10 cc anteriorly,the band is placed just below the cardia, and no pouch dilatation has been found. The important factor may not be the type of band but rather the technical approach.     

Virtual Gastroduodenoscopy: A New Look at the Bypassed Stomach and Duodenum After Laparoscopic Roux-en-Y Gastric Bypass for Morbid Obesity

Background: After open or laparoscopic Roux-en-Y gastric bypass (RYGBP) for morbid obesity, the bypassed stomach and duodenum are not readily available for radiological and endoscopic evaluation. Furthermore, little is known about the long-term physiologic and histologic changes that occur in the bypassed GI segments following these procedures. Many alternative radiological and endoscopic techniques have been described to access the distal gastric pouch and the duodenum after RYGBP. Apart from percutaneous gastrografin? studies, all these techniques require the insertion of a gastrostomy tube in the distal stomach. Methods: a new diagnostic method to access the bypassed segments by virtual CT gastroscopy (VG) was used in 5 morbidly obese patients who underwent laparoscopic RYGBP (LRYGBP). Results: All patients tolerated the procedure well, which appears safe and suitable for an outpatient setting.The virtual images offered an excellent intraluminal view of the stomach and duodenum. Conclusions: VG holds promise as the method of choice in the follow-up of LRYGB patients, having the potential to detect inflammatory changes and cancer in the excluded segments early.     

Gastric Emptying Rate Measurement after Vertical Banded Gastroplasty

Background: In vertical banded gastroplasty (VBG), a small proximal gastric pouch is created, which is believed to fill rapidly and to empty slowly. Methods: In 13 patients who underwent VBG, gastric emptying rate was measured. A radiolabelled solid test meal was used before and 2 weeks after operation. From a region of interest above the whole stomach, the proximal pouch and the distal stomach, half emptying time as well as retention percentage were derived. Results: All patients experienced early satiety and gastric fullness after ingestion of a small test meal. The proximal pouch emptied rapidly.The evacuation of the test meal from the whole gastric region as well as the distal stomach were not altered significantly by the operation. Conclusion: VBG is a safe operation which reduced weight significantly. Early satiety, however, induced by this technique, cannot be explained alone by slow emptying of the proximal pouch. The nature of the outlet of the pouch as well as the behavior of its wall must be considered.     

Transesophageal gastrostomy

For gastrostomy after thoracic esophagus extirpation its distal stump was used. It is confirmed, that transesophageal gastrostomy has a number of advantages. Pezzer's catheter can be used as gastrostomic tube which self-fixes in given position and secures reliable gastrostoma sealing. Suturing of the stomach to parietal peritoneum around gastrostoma is not more necessary. Deformation and reduction of the stomach size are excluded and stomach is kept ready for subsequent plastic replacement of the oesophagus. The operation gets oncologically more radical as a result of removal of paraesophageal cellular fat and potentially metastatic lymph nodes during mobilization of the oesophagus and cardia distal stump. The routine technique of transesophageal gastrostomy is described. This technique is applied in 17 patients. Complications were not registered.     

Management of Anastomotic Leaks After Laparoscopic Roux-en-Y Gastric Bypass

Background Anastomotic leaks after bariatric surgery carry high morbidity and mortality. We aimed to describe our experience of the diagnosis and management of gastrointestinal anastomotic leaks in patients undergoing laparoscopic gastric bypass in a single institution. Methods Of 1,200 patients who underwent laparoscopic Roux-en-Y gastric bypass with manual gastrojejunal anastomosis for morbid obesity from January 2002 to January 2007, we retrospectively analyzed 59 patients with anastomotic leak. The location of the leak, day of diagnosis, diagnostic methods, clinical manifestations, treatment modalities, associated complications, and length of hospital stay were analyzed. Results Leaks were located as follows: 67.8% in the gastrojejunostomy, 10.2% in the gastric pouch, 3.4% in the excluded stomach, 5.1% in the jejunojejunal anastomosis, 3.4% in the gastrojejunostomy plus pouch, 3.4% in the pouch plus excluded stomach, and 6.8% in undetermined sites. Routine upper gastrointestinal series revealed contrast extravasation in nine patients (15.3%). Leaks were asymptomatic at diagnosis in 29 patients (49.2%). Surgical reintervention was carried out in 23 patients, and conservative treatment was provided in the remaining 36. Transfer to the intensive care unit was required in 11 patients, with five deaths (0.4%). Conclusion In our experience, most anastomotic leaks can be managed with conservative measures alone. In many patients, abdominal drains are effective in the management of leaks, obviating the need for reintervention. Nasoenteral nutrition was effective in the non-operative management of gastrojejunal leaks in patients without signs of systemic toxicity.     

Safe Intestinal Decompression in Fresh Postoperative Gastric Bypass

Background: Dilatation of the Roux-limb is sometimes found following Roux-en-Y gastric bypass (RYGBP) procedures. This could be the result of a transient episode due to ileus, or a partial or complete obstruction. The risk of this complication is an increase in intraluminal pressure with the potential for leak. Blind insertion of a nasogastric tube for decompression could be risky due to possible perforation at the stapled or sutured edges. Methods and Results: The diagnosis was made with routine extended upper gastrointestinal x-rays 24 hours after surgery. To determine the relationship of the intestinal dilatation, increase in intraluminal pressures and leaks, measurements were taken in porcine models duplicating a RYGBP. Pressures obtained at the anastomoses were higher than pressures in the jejunum between the anastomoses, and related directly to the production of leaks. Elevations of intraluminal intestinal pressures have also been observed in patients who required decompression. The angles of a freshly constructed pouch and the recent stapled or sutured edges may be easily perforated with a nasogastric tube, especially a hard one. We use a soft flexible tube. An angled-end 0.035" wire is introduced into the intestines with fluoroscopic assistance. The tube tip is perforated with a needle, and through this opening, the wire is passed into the tube. The tube is then fed over the wire for safe decompression. Conclusion: Decreasing the intestinal pressure by safe decompression may avoid one of the causes of leaks.     

New simplified intestinal decompression tube

Since it has been demonstrated that mercury in a balloon tipped tube will carry the tube down the gastrointestinal tract, there is no longer the need for a double lumen tube. We have presented twenty-two cases of severe intestinal distention which were treated by a single lumen intestinal tube and in which the results were far better than our expectations. In all cases, the tube was carried far down the ileum or into the colon by the mercury. The caliber of the lumen in the tube used is considerably larger than in the currently used tubes and the number of holes were increased to sixteen. These sixteen holes are spread over an area of twenty-four inches. The size of the holes are also much larger than in any of the currently used tubes and the shape of the holes, we believe, contributes immeasurably to the excellent results obtained as plugging with particulate matter did not occur. Only one word of caution must be uttered at this time; that is, after the last hole has been inserted into the nose, do not insert more than six inches of tube until the balloon has passed through the pylorus and into the duodenum. It takes one to two hours for the balloon to pass into the duodenum, then the tube is advanced six inches every two hours. If too much tube is inserted into the stomach before the balloon has passed into the duodenum, coiling of the tube will occur with the resultant danger of knot formation.     

Technical Alternatives Laparoscopic Distal Gastric Bypass for Morbid Obesity in a Porcine Model

Background: Laparoscopic gastric bypass and vertical banded gastroplasty are two procedures used in the treatment of morbid obesity. The authors describe alternative techniques of laparoscopic distal gastric bypass as a modification of the Scopinaro procedure, which were used experimentally in a porcine model. Methods: Five pigs were used. The laparoscopic procedure was performed with the pigs under general anesthesia after pneumoperitoneum had been achieved. Five or six trocars were used. One port was converted from 12 to 33 mm, and all the other ports were 10-11 mm. The initial surgical technique was similar to that used by others for laparoscopic gastrectomy, except that atraumatic ultracision was used for all the dissection. The stomach was stapled with a linear cutter stapler (Endopath, 31 mm) to create a 50-ml pouch. The ileum was divided with a linear cutter-stapler (Endopath, 31 mm) or ultracision cautery. A long length of ileum was positioned between the stomach pouch and the jejunoileostomy. Only 50-70 cm of terminal ileum was preserved as a common channel. In three animals, the circular stapler (ILS, 21 mm) was used to produce an end-to-side anastomosis. In one animal, two purse-string sutures were handsewn in the ileum and jejunum stumps, and in another two animals, two endoloops were used for the anvil. In two animals, the linear stapler was used to form a side-to-side pouch stomach-ileum and jejunoileostomy anastomosis. In other animals, the two types of anastomosis have been combined. All animals were killed after surgery so that the anastomoses could be evaluated for size and integrity. Results: In all animals, with the circular and linear stapler, both 21 and 13-15 mm anastomoses were intact. Conclusion: Distal gastric bypass is feasible laparoscopically, with intact anastomoses.     

Evaluation of cuffed tracheal tube size predicted using the Khine formula in children

BACKGROUND: The correct size of cuffed endotracheal tube (CET) limits the risk of postintubation tracheal damage. The aim of this study was to compare the size of the CET used in children with the size predicted by the Khine formula [age (years)/4 + 3]. METHODS: After ethical committee approval, 204 children aged 1 day-15 years were included prospectively in the study. The choice of the size of the CET was made at the discretion of the attending anesthesiologist. The main criterion of judgment was the comparison of the leak before and after inflating the cuff at a pressure of 20 cm.H(2)O. Demographic data, tracheal tube size used and that predicted by Khine's formulae and side-effects were recorded. RESULTS: Overall, 21% of the CET were in accordance with the size predicted by the Khine formula. In the remaining patients, 72% were oversized and 7% undersized. In 12 cases, the size of CET chosen initially was modified: for a larger size in eight children and for a smaller size in four others. Six children (2.9%) presented with minor postoperative complications. CONCLUSIONS: Our data suggest that Khine's formula for predicting the appropriate tracheal tube size underestimates optimal size by 0.5 mm. We therefore recommend the use of the following formula: internal diameter of the CET = [age/4 + 3.5] in children >1 year of age which may be applied without increased risk of complications. The rate of tracheal reintubation as well as the detected leaks supports these recommendations.     

The Micropouch Gastric Bypass: Technical Considerations in Primary and Revisionary Operations

Background: Roux-en-Y gastric bypass is an effective procedure for the long-term control of morbid obesity. An eventual revisionary operation, however, is necessary for some patients (0.8-29%). Redo procedures are required for pouch enlargement, stapleline dehiscence, or marginal ulceration. In 1994, the micropouch gastric bypass (MBG) was developed to eliminate the need for a repeat operation. Its design was based on two anatomical principles: 1) The fundus is elastic, aperistaltic, and may significantly dilate over time; 2) The proximal magenstrasse contains a high concentration of parietal cells, which potentiates the risk for marginal ulceration or gastroesophageal reflux after vertical pouch restriction. Construction of a micropouch limited to the gastric cardia avoids using the fundus and proximal lesser curvature, but requires a greater mobilization of the stomach and its peritoneal attachments. Methods: Between February 1994 and February 2000, 1,120 patients underwent the MGB as a primary or revisionary operation.The fundus was mobilized completely, including transection of the left phreno-esophageal and gastrophrenic ligaments. The transected pouch was limited to the gastric cardia with 1 cm of fundus incorporated into the gastrojejunostomy stoma (GJS). Results: There were 10 anastomotic leaks at the GJS (0.9%). All leaks sealed following surgical drainage or parenteral nutrition. One patient required re-operation (0.09%) for a dilated pouch and marginal ulceration. An additional patient (0.09%) developed a gastrogastric fistula secondary to a pharmacobezoar and stomal stenosis. Conclusion: With an appreciation for the finer anatomy of the proximal stomach and intra-abdominal esophagus, the micropouch can be constructed safely in both primary and redo procedures. The MGB, now in its seventh year, is durable and has, with rare exception, eliminated pouch enlargement, staple-line separation, reflux esophagitis, and marginal ulceration.     

Reconstruction after Distal Gastrectomy by Interposition of a Double-jejunal Pouch Using a Triangulating Stapling Technique

Abstract Sustaining good nutrition and preventing postgastrectomy syndrome are important for increasing the quality of life after distal gastrectomy. Many surgeons have proposed surgical methods designed to enhance long-term patient quality of life. An immediate, safe method based on current physiologic reconstructive principles shown to reduce postoperative patient complaints is presented. A reconstructive method using a modified interpositioned double-jejunal pouch after distal gastrectomy in 18 cancer patients was reviewed. This method uses a triangulating stapling technique with wide end-to-side anastomosis between the residual stomach and the pouch. In all patients, the anastomosis site was without leakage or stenosis, and there were no episodes of severe reflux esophagitis, residual gastritis, or dumping syndrome. The mean pooling rate was 44.2%, and emptying half-time was 73.0 minutes. After 2 years the body weight was 91.3% of the preoperative weight, the food volume was 89.2% of normal intake, and meal frequency was 3.0 per day. This method of reconstruction is useful for immediate and safe creation of a wide anastomosis between the residual stomach and the double-jejunal pouch after distal gastrectomy and in the prevention of esophagitis and residual gastritis.     

Gastric dissociation for the treatment of congenital microgastria with paraesophageal hiatal hernia

Microgastria is a rare but well-described congenital anomaly of the alimentary tract that presents in the neonatal period with vomiting, aspiration, and failure to thrive. Based on a relatively small number of case reports, gastric augmentation with a double-barrel loop of jejunum, known as a Hunt-Lawrence pouch, has been advocated as the reconstructive procedure of choice in affected children who fail nonoperative management. In this report, we present a novel method of foregut reconstruction in an infant with congenital microgastria and a paraesophageal hiatal hernia. In this procedure, the stomach was transected 1 cm below the gastroesophageal junction with construction of a straight Roux-en-Y jejunal anastomosis to the gastric fundic cuff. A feeding gastrostomy tube was placed into the distal remnant stomach for enteral access. The patient did well and eventually transitioned to full oral feeds by 3 years of age.     

Laparoscopic gastric bypass complicated by gastric pouch necrosis: considerations in gastroesophageal reconstruction

Gastric pouch necrosis and intraabdominal sepsis is an uncommon complication following laparoscopic gastric bypass. The intraoperative management of this complication centers on resection of the necrotic pouch, esophageal diversion, drainage, and enteral access for nutrition. Reestablishing gastrointestinal continuity at a later surgery following this complication can be challenging. We present a case in which the colon was found to be unacceptable for use in reconstruction; the remaining stomach was used as the conduit for a transhiatal reconstruction of gastrointestinal continuity instead.     

Pouch operation for rectal cancer

Many retrospective studies have found that the functional outcome after a low anterior resection for rectal cancer is better with colonic J-pouch reconstruction than with conventional straight anastomosis. This advantage was demonstrated in prospective, randomized trials and meta-analyses. However, despite its increasing popularity there are several areas of controversy about the use of the colonic J-pouch reconstruction. These issues include anastomotic leaks, the part of the colon used for the pouch, the pouch size, causes of difficulty in evacuation, indications (the optimum level of anastomosis), appropriateness for the elderly, and long-term (2 years or more after surgery) functional outcome. All relevant articles identified from MEDLINE databases were reviewed. The incidence of anastomotic leaks is apparently reduced by colonic J-pouch reconstruction. A 5-cm colonic J-pouch using the sigmoid colon increases the reservoir function without compromising evacuation, and provides better functional outcome than straight anastomosis, even 2 years or more after surgery, in patients whose anastomosis is less than 8 cm from the anal verge. Patients with ultralow anastomoses, less than 4 cm from the verge, appear to benefit the most. At a time when the indications for abdominoperineal excision appear to be reduced for low rectal cancer, the demand for colonic J-pouch reconstruction (the best technique in pouch operations) is therefore likely to increase.     

The right approach to carcinoma of the cardia and lower oesophagus.

Successful surgical palliation for carcinoma of the cardia and lower oesophagus is often compromised by anastomotic failure or local recurrence. These complications follow technical difficulty in achieving adequate resection and a safe anastomosis through inappropriate surgical exposure, often via the left chest. A technique of oesophagogastrectomy is described employing a simultaneous right abdominothoracic approach without division of either costal margin or diaphragm. Synchronous laparotomy and thoractomy facilitates both resection and anastomosis, and obviates the necessity to turn the patient over and redrape halfway through the operation. Closure of the distal stomach and the gastro-oesophageal anastomosis are performed using staplers. No anastomotic leaks were detected in the 15 patients described.     

Intraoperative Endoscopic Test Resulting in No Postoperative Leaks from the Gastric Pouch and Gastrojejunal Anastomosis in 366 Laparoscopic Roux-en-Y Gastric Bypasses

Background: Postoperative leak from the gastric pouch and the anastomosis are leading causes of morbidity and mortality after gastric bypass. Many modalities have been emerging to prevent this complication. 326 consecutive laparoscopic Roux-en-Y gastric bypasses (LRYGBP) were analyzed in a two-surgeon practice and found no incidence of leaks from the gastric pouch (GP) and the gastrojejunal anastomosis (GJA) with intraoperative endoscopic testing. Methods: 328 consecutive RYGBP performed in antecolic fashion from March 2003 to January 2004 were analyzed. 326 (99%) were performed laparoscopically. After creating a 15 to 25 cc gastric pouch, integrity of the GP and GJA was tested for leak under saline submersion with endoscopic insufflation and placement of a bowel clamp on the intestinal limb distal to the GJA. Suture repair of apparent leak was performed if needed. Results: Of 326 consecutive LRYGBP utilizing the endoscopic leak test, there was no incidence of leak from the GP or GJA. There was one leak from the jejuno-jejunosotmy which was repaired laparoscopically on postoperative day #1. There was no incidence of leaks in the 2 open RYGBPs. Conclusions: Many "leak prophylaxis" measures have been emerging to prevent this potentially devastating complication. However, checking the GP and GJA with a simple endoscopic test can minimize the incidence of leaks after LRYGBP.     

A new Idea for a Protective Balloon System During Carotid Stenting

Summary  Percutaneous transluminal angioplasty with stenting for high-grade carotid stenosis has been recently come into use. However, distal embolic events remain a problem with this procedure compared to results with established carotid endarterectomy. To counteract such problems, various blocking balloon system such as a simple distal blocking balloon system or a thrombi catching system have been used in some instances. This time, a double-balloon system was used as a proximal blocking system during predilation, and an existing distal blocking system was used during practical carotid stenting. These systems were applied to six cases. In addition, we used a modified conventional blood transfusion system for filtration and retrieval of the aspirated blood. Compared with the simple distal blocking balloon system, occurrence of distal emboli could be reduced with our new combined method although the number of cases is too small to reach any definite conclusions.