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Featured researches published by W. Kneist.


Diseases of The Colon & Rectum | 2003

Influence of identification and preservation of pelvic autonomic nerves in rectal cancer surgery on bladder dysfunction after total mesorectal excision.

Theodor Junginger; W. Kneist; Achim Heintz

AbstractPURPOSE: Given the improvement in oncologic outcome after the introduction of total mesorectal excision for the treatment of rectal cancer, the objective of the present study was to determine the frequency of identification and preservation of the pelvic autonomic nerves and to identify a possible link between postoperative micturition disturbances and the extent of the radical resection. METHODS: Between March 1997 and December 2001, 150 patients with adenocarcinoma of the rectum (≤16 cm from the anal verge) underwent surgery, with sphincter preservation in 112 cases (74.7 percent). Sixty-three patients (42 percent) were classified as American Society of Anesthesiologists Stage III and two (1.3 percent) as Stage IV. The number of cases with complete identification, partial identification, or nonidentification of the autonomic nerves (superior hypogastric plexus, hypogastric nerve, and inferior hypogastric plexus) was documented and correlated with micturition disturbances (need for a long-term urinary catheter). Urine volumes were measured by ultrasound before and after surgery. RESULTS: The pelvic autonomic nerves were identified completely in 108 patients (72 percent), partially in 16 (10.7 percent), and not at all in 26 (17.3 percent). After the initial phase of the study (n = 50 patients), complete identification was realized in 78 percent of cases. Multivariate analysis showed that of the predetermined parameters (learning curve for Group I vs. Groups II or III, gender, T stage, blood loss, curative surgery, and previous surgery), gender (P = 0.006), learning curve (P = 0.019), and depth of penetration of the rectal wall (T1/T2 vs. T3/T4; P = 0.028) exerted an independent influence on achievement of complete pelvic nerve identification. Sixteen patients (10.7 percent) were discharged from the hospital with a urinary catheter. Identification and preservation of the pelvic autonomic nerves was associated with low bladder dysfunction rates (4.5 vs. 38.5 percent; P < 0.001). In the evaluation of preoperative and postoperative bladder function, a urologic history and residual urine volume measurements by ultrasound were essential. The information obtained from urodynamic studies was of no relevance. CONCLUSIONS: Identification and preservation of the pelvic autonomic nerves was achieved in the majority of patients and led to the prevention of urinary dysfunction. Gender (P = 0.006), learning curve (P = 0.019), and T stage are independent parameters that influence outcome.


World Journal of Surgery | 2003

Positron Emission Tomography for Staging Esophageal Cancer: Does It Lead to a Different Therapeutic Approach?

W. Kneist; Mathias Schreckenberger; Peter Bartenstein; Frank Grünwald; Katja Oberholzer; Theodor Junginger

Accurate preoperative staging is essential for the indication and selection of the appropriate surgical procedure in patients with esophageal cancer. The present prospective study was designed to determine if the preoperative use of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) increases the accuracy of staging esophageal cancer compared with computed tomography (CT) and if it thereby leads to a different therapeutic approach. A total of 58 patients, 46 men and 12 women (mean age 61 years), with histologic proof of esophageal carcinoma underwent FDG-PET of the neck, chest, and abdomen, as well as CT of the chest and abdomen, to determine tumor stage. FDG-PET and CT data were compared with each other and with pathohistologic findings. Sensitivity, specificity, and overall accuracy for detecting histologically verified lymph node and distant metastases were calculated for FDG-PET and CT. FDG-PET showed a higher specificity, whereas CT had higher accuracy for detecting both abdominal (73% vs. 59%) and thoracic (73% vs. 63%) lymph node metastases. The accuracy of detecting blood-borne and lymphatic distant metastases was identical for CT and FDG-PET imaging (50%). FDG-PET had a higher specificity than CT (87% vs. 13%) but lower sensitivity (35% vs. 67%). FDG-PET did not provide new information on the indication for surgery, nor was it helpful for choosing the appropriate surgical procedure in patients with esophageal carcinoma. In view of the relatively high cost of FDG-PET examinations, the use of this modality is indicated primarily in patients with inconclusive CT findings or for scientific research projects. Higher sensitivity as a result of tumor-affinity radiopharmaceuticals and optimized apparatus resolution, in addition to the advantages offered by whole-body PET scanning, may lead to new indications for this staging procedure in the future.


Nature Genetics | 2014

Common variants in the HLA-DQ region confer susceptibility to idiopathic achalasia

Ines Gockel; Jessica Becker; Mira M. Wouters; Stefan Niebisch; Henning R. Gockel; Timo Hess; David Ramonet; Julian Zimmermann; Ana G. Vigo; Gosia Trynka; Antonio Ruiz de León; Julio Pérez de la Serna; Elena Urcelay; Vinod Kumar; Lude Franke; Harm-Jan Westra; Daniel Drescher; W. Kneist; Jens U. Marquardt; Peter R. Galle; Manuel Mattheisen; Vito Annese; Anna Latiano; Uberto Fumagalli; Luigi Laghi; Rosario Cuomo; Giovanni Sarnelli; Michaela Müller; Alexander J. Eckardt; Jan Tack

Idiopathic achalasia is characterized by a failure of the lower esophageal sphincter to relax due to a loss of neurons in the myenteric plexus. This ultimately leads to massive dilatation and an irreversibly impaired megaesophagus. We performed a genetic association study in 1,068 achalasia cases and 4,242 controls and fine-mapped a strong MHC association signal by imputing classical HLA haplotypes and amino acid polymorphisms. An eight-residue insertion at position 227–234 in the cytoplasmic tail of HLA-DQβ1 (encoded by HLA-DQB1*05:03 and HLA-DQB1*06:01) confers the strongest risk for achalasia (P = 1.73 × 10−19). In addition, two amino acid substitutions in the extracellular domain of HLA-DQα1 at position 41 (lysine encoded by HLA-DQA1*01:03; P = 5.60 × 10−10) and of HLA-DQβ1 at position 45 (glutamic acid encoded by HLA-DQB1*03:01 and HLA-DQB1*03:04; P = 1.20 × 10−9) independently confer achalasia risk. Our study implies that immune-mediated processes are involved in the pathophysiology of achalasia.


World Journal of Surgical Oncology | 2005

Transhiatal and transthoracic resection in adenocarcinoma of the esophagus: Does the operative approach have an influence on the long-term prognosis?

Ines Gockel; Sina Heckhoff; Claudia M Messow; W. Kneist; Theodor Junginger

BackgroundThe goal of the present analysis was to investigate the long-term prognosis for adenocarcinoma of the esophagus treated with either the transhiatal (TH) or the transthoracic (TT) operative approach.MethodsBetween September 1985 and March 2004, esophageal resection due to carcinoma was performed on a total of 424 patients. This manuscript takes into account the 150 patients suffering from adenocarcinoma of the esophagus in whom a transhiatal resection of the esophagus was performed. In the event of transmural tumor growth and a justifiable risk of surgery, the transthoracic resection was selected. An extended mediastinal lymph node dissection, however, was only carried out in the course of the transthoracic approach.ResultsThe transthoracic resection of the esophagus demonstrated a higher rate of general complications (p = 0.011) as well as a higher mortality rate (p = 0.011). The mediastinal dissection of the lymph nodes, however, revealed no prognostic influence. Considering all of the 150 patients with adenocarcinoma, as well as only those patients who had undergone curative resections (R0), the transhiatal approach was seen to demonstrate a better five-year survival rate of 32.1% versus 35.1%, with a median survival time of 24 versus 28 months, as compared with those who had undergone a transthoracic approach with a five-year survival rate of 13.6% (all patients) versus 17.7% (R0 resection) with a median survival time of 16 versus 17 months (p < 0.05).ConclusionThe prognosis in patients with adenocarcinoma of the esophagus is influenced by the depth of the tumor (pT) and the pM-category, as shown in the multivariate analysis. The present analysis did not demonstrate a relevant difference in survival for patients with N0 and N1 stages undergoing transhiatal or transthoracic esophagectomy. It is questionable, if a more extensive mediastinal lymph node dissection, in addition to the clearance of abdominal lymph nodes, offers prognostic advantages in adenocarcinoma of the esophagus. However, the morbidity and mortality associated with the transthoracic approach is higher.


British Journal of Surgery | 2005

Major urinary dysfunction after mesorectal excision for rectal carcinoma

W. Kneist; A. Heintz; Theodor Junginger

Urinary dysfunction may occur after mesorectal excision and pelvic autonomic nerve preservation (PANP) in patients with rectal carcinoma. The aim of this prospective study was to identify factors predictive of long‐term urinary catheterization.


World Journal of Surgery | 2007

Male urogenital function after confirmed nerve-sparing total mesorectal excision with dissection in front of Denonvilliers' fascia.

W. Kneist; Theodor Junginger

This prospective study addresses the rate of male genital dysfunction following total mesorectal excision (TME) for rectal carcinoma using the anterior extramesorectal plane and its correlation with early urinary function, pelvic autonomic nerve preservation (PANP), and intraoperative neurostimulation (INS). A consecutive series of 44 men operated on by the same surgical team was analyzed. After excluding 18 patients considered to be impotent preoperatively, urogenital function was evaluated in 26 patients on the basis of the International Prostatic Symptom Score and International Index of Erectile Function. PANP was assessed with INS of parasympathetic nerves. PANP was complete in 21 patients (80.8%). Deterioration of urinary function was observed in six patients (23.1%) at early follow-up. Postoperative erectile dysfunction assessed in seven patients (26.9%) was associated with micturition disturbances in four (57%). Despite dissection in front of Denonvilliers´ fascia, the incidence of erectile dysfunction was low in patients with nonanterior tumors (1/10). INS results had higher sensitivity for predicting urinary dysfunction than for predicting erectile dysfunction (67% vs. 43%). Values for specificity and accuracy were 95% and 90%, and 89% and 77%, respectively. The correlation between the findings on INS and urinary function was good (κ = 0.66) at a fair (κ = 0.36) correlation for erectile function. Nerve-sparing TME using the anterior extramesorectal plane results in a justifiable rate of postoperative impotence in patients with nonanterior tumors. Patients with negative results on INS or early urinary dysfunction are at greater risk of erectile dysfunction.


Journal of The American College of Surgeons | 2012

Total Mesorectal Excision with Intraoperative Assessment of Internal Anal Sphincter Innervation Provides New Insights into Neurogenic Incontinence

W. Kneist; Daniel W. Kauff; Ines Gockel; Sabine Huppert; Klaus Peter Koch; Klaus Peter Hoffmann; Hauke Lang

BACKGROUND The aim of this prospective study was to assess internal anal sphincter (IAS) innervation in patients undergoing total mesorectal excision (TME) by intraoperative neuromonitoring (IONM). STUDY DESIGN Fourteen patients underwent TME. IONM was carried out through pelvic splanchnic nerve stimulation under continuous electromyography of the IAS. Anorectal function was assessed with the digital rectal examination scoring system and a standardized questionnaire. RESULTS Nine of 11 patients who underwent low anterior resection had positive IONM results, with stimulation-induced increased IAS electromyographic amplitudes (median 0.23 μV (interquartile range [IQR] 0.05, 0.56) vs median 0.89 μV (IQR 0.64, 1.88), p < 0.001) after TME. The patients with the positive IONM results were continent after stoma closure. Of 2 patients with negative IONM results, 1 had fecal incontinence after closure of the defunctioning stoma and received a permanent sigmoidostomy. In the other patient the defunctioning stoma was deemed permanent due to decreased anal sphincter function. In 3 patients who underwent abdominoperineal excision, IONM assessed denervation of the IAS after performance of the abdominal part. CONCLUSIONS This study demonstrated that IONM of IAS innervation in rectal cancer patients is feasible and may predict neurogenic fecal incontinence.


International Journal of Colorectal Disease | 2007

Intraoperative electrostimulation objectifies the assessment of functional nerve preservation after mesorectal excision

W. Kneist; Theodor Junginger

BackgroundTo improve nerve-sparing surgery, intraoperative electrical stimulation of pelvic autonomic nerves (INS) has been proposed in urology, gynecology, and visceral surgery. The aim of this study was to assess the impact of INS while monitoring intravesical pressure on the accurate evaluation of pelvic autonomic nerve preservation (PANP) after mesorectal excision. It was sought to determine whether this confirmation is useful in the prediction of postoperative urinary function.MethodsSixty-two patients with mesorectal exzision for rectal cancer were examined prospectively. PANP was assessed visually by the surgeon and with INS. Bladder function was evaluated by post voiding residual volume measurement, rate of recatheterization, rate of long-term urinary catheterisation, and the international prostatic symptom score with quality of life index.ResultsINS confirmed bilateral preservation of parasympathetic nerves in 46 patients (74%), and in 10 patients (16%) in at least one side. In six patients (10%), INS failed to confirm PANP. Eleven patients (18%) developed urinary symptoms postoperatively. INS results had a higher sensitivity than visual assessment by the surgeon (82 vs 46%). Values for specificity ranged at 90 and 92%, respectively. Accuracy of INS in predicting PANP was higher (88 vs 83%). The correlation between urinary function and the findings on INS was good (kappa-value: 0.65), correlation between urinary function and visual assessment by the surgeon was fair (kappa-value: 0.40).ConclusionINS, while monitoring intravesical pressure, accurately predicts bladder function after mesorectal excision. It may provide further insight into pelvic autonomic nerve sparing techniques.


Surgical Endoscopy and Other Interventional Techniques | 2005

Endoscopic adrenalectomy: an analysis of the transperitoneal and retroperitoneal approaches and results of a prospective follow-up study

Ines Gockel; W. Kneist; A. Heintz; J. Beyer; Theodor Junginger

BackgroundEndoscopic adrenalectomy is currently performed using either a retroperitoneal or transperitoneal approach. The aim of this study was to determine which of these is the optimal surgical technique in a prospectively designed analysis of a large series of patients operated on by a single team over a 10-year period.MethodsFrom February 1994 to March 2004, 267 endoscopic adrenalectomies (retroperitoneal in 132 patients and transperitoneal in 135 patients) were performed in 245 consecutive patients. There were 102 right lateral and 121 left lateral procedures (22 patients had a bilateral procedure). The most prevalent indication was incidentaloma (35.9%), followed by pheochromocytoma and Conn’s adenoma.ResultsThe endoscopic procedure was performed in 238 of 245 patients (97.1%). The conversion rate was 1.5% for the transperitoneal approach and 3.8% for the retroperitoneal approach. No statistically significant influence was noted for the parameters of intraoperative blood loss, rate of postoperative complications, and duration of hospital stay with regard to the surgical technique. The operative time and the learning curve proved to be significantly longer for the retroperitoneal adrenalectomy. In addition, a variance analysis identified tumor size (>5 cm) as a significant factor influencing the operative time, whereas body mass index and localization (right/left lateral) did not prove significant.ConclusionIndependent of the underlying pathology, endoscopic adrenalectomy using either the trans- or retroperitoneal approach can be performed in 96-98% of all patients. Differences between the two techniques in operative time and learning curves clearly favor the transperitoneal adrenalectomy.


Digestive Diseases | 2004

Subtotal Esophageal Resection in Motility Disorders of the Esophagus

Ines Gockel; W. Kneist; Volker F. Eckardt; Katja Oberholzer; Theodor Junginger

Background: Esophagectomy for motility disorders is performed infrequently. It is indicated after failed medical therapy, pneumatic dilation, non-resecting surgical and redo procedures. Patient selection in this group is challenging and the operative risk has to be weighted carefully against the poor quality of life with persistent or recurrent dysphagia. Patients and Methods: Between September 1985 and April 2004, subtotal esophageal resections for advanced esophageal motility disorders of the esophagus not responding to previous therapy were carried out in 8 patients (6 females, 2 males). The median age of these patients was 59.5 (43–78) years. Six patients had a megaesophagus secondary to achalasia; 1 patient had a non-specific esophageal motility disorder with a stenosis of the distal esophagus, and a further patient displayed a recurrent huge epiphrenic diverticulum, which occurred in the context of a collagen disease. A transhiatal esophageal resection was performed in 6, a transthoracic procedure in 2 patients. Results: Outcome assessment was done after a follow-up of 43.5 (3–92) months in median. The resection and reconstruction of the esophagus in advanced and decompensated esophageal motility disorders led to a marked functional improvement with disappearance of dysphagia. Despite previous therapeutic failures, alimentation could be restored in all patients. Conclusion: Favourable long-term results with significant improvement of symptoms can be achieved by esophageal resection even if endoscopic therapy or non-resecting surgical measures are unsuccessful. Transhiatal esophagectomy with gastric pull-up should be the preferred procedure and can be performed with low morbidity.

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