Comparative Histopathological Analysis of Nasal Osteotomy Techniques in a Rabbit Model.

Objective: Nasal osteotomy is a crucial step in rhinoplasty, explicitly addressing the open roof deformity in nasal bones. This study aimed to assess and compare the recovery patterns associated with 4 distinct osteotomy techniques in a rabbit model. Materials and Methods: Twenty white New Zealand rabbits weighing 2.5 to 3.0 kg were included in the study. Median osteotomies were performed on the left side using piezosurgery and on the right side using an oscillating micro-saw. Additionally, internal osteotomy was executed on the right side and external osteotomy on the left side, both performed with a chisel across all rabbits. Ten rabbits were sacrificed on the 7th day, while the remaining 10 were sacrificed on the 15th day for subsequent histological examination. The granulation tissue formation (GTF), vascularization, inflammation, collagen fibril content, osteotomy gap width, and new bone formation were evaluated in hematoxylin and eosin and Masson's trichrome-stained sections. Results: On the 7th day, piezosurgery demonstrated statistically-significant advantages in terms of GTF, neovascularization, and collagen fibril quantity when compared to the oscillating micro-saw (P < .05). Furthermore, a statistically-significant difference was observed among the groups concerning the distribution of connective tissue organization between the 7th and 15th days (P < .05). Conclusions: This study's findings unequivocally establish that bone healing after osteotomy with piezosurgery surpasses that achieved with an oscillating micro-saw in this rabbit model.

The Tricellufuse Technique for Closing Nasal Septal Perforations.

Objective: Nasal septal perforation (NSP) is a structural anomaly that affects the mucosa, cartilage, and bone of the nasal septum, often stemming from septoplasty as the primary cause. Spontaneous healing of a perforated septum is rare, and typically the healing process is observed until it is determined that the condition is stable and no longer deteriorating, at which point surgical intervention is considered. Numerous surgical techniques have been proposed for NSP repair. This study introduces a novel approach incorporating a fascia lata graft with fat tissue and diced septal cartilage to reconstruct medium-sized NSP. Methods: The researchers conducted a retrospective analysis involving 22 patients who underwent repair for NSP from January 2021 to January 2023. Grafts were obtained, and the perforation was addressed using an open rhinoplasty technique, followed by the insertion and suturing of the graft. Results: The mean size of the septal perforations was 12 mm horizontally and 13 mm vertically. All patients with NSPs were chosen as medium size (within 0.5-2 cm). The mean follow-up period was 12 months. Complete closure of NSP was achieved in 19 out of 22 patients (86.3%). Among the cases, 15 were male (68%), and the ages ranged from 25 to 45 years with a mean of 35. Eight cases (36%) were smokers. After 12 months postoperatively, closure was not achieved in 3 medium-sized NSPs due to smoking. . The analysis revealed that the failure rate in the smoker group was statistically significant (P = .036). Conclusion: The TriCelluFuse technique, combining fascia lata, fat tissue, and diced septal cartilage, is a secure and reliable method for closing NSPs. It has a significant success rate and should be considered a viable option for individuals with NSPs.

Innovative Repair Method for Septal Perforation Repair: The Fascia Lata and Platelet-Rich Plasma Fusion Technique.

BACKGROUND: Nasal septal perforation (NSP) is a structural flaw that affects the mucosa, cartilage, and bone of the nasal septum, often stemming from septoplasty as the most frequent cause. The natural healing of a perforated septum is uncommon; on the contrary, it tends to deteriorate progressively. Various surgical methods have been outlined for the repair of NSP. In this research, the authors introduce an innovative approach utilizing fascia lata graft with PRP for the restoration of NSP across diverse sizes. METHODS: The researchers conducted a retrospective analysis involving 25 patients who underwent repair for nasal septal perforation (NSP) from January 2021 to January 2023. Grafts were obtained, and the perforation was addressed using an open rhinoplasty technique, followed by the insertion and suturing of the graft. RESULTS: The mean size of the septal perforations was 17 mm horizontally and 18 mm vertically. The mean follow-up period was 12 months. Complete closure of NSP was achieved in 23 out of 25 patients (92%). Among the cases, 17 were male (68%), and the age ranged from 25 to 45 years with a mean of 38.7. Eight cases (32%) were smokers. At 12 months postoperatively, three large-sized NSPs were closed successfully, while two medium-sized NSPs did not achieve closure due to smoking. CONCLUSION: The Fascia Lata and Platelet-Rich plasma fusion technique for the closure of nasal septal perforations is a secure and dependable method, demonstrating a notable success rate. This approach should be regarded as a viable option for individuals dealing with nasal septal perforation. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the table of contents or the online instructions to authors www.springer.com/00266 .

Fascia Lata-Fat Island Graft in Septal Perforation Repair.

Objective: To measure the success of the fascia lata-fat island graft technique in septal perforation repair as measured by nasal endoscopic examination. Background: This study presents the results of using fascia lata-fat island, a different graft technique, for the repair of septal perforations, offering an alternative to this challenging procedure. Methods: This retrospective study assesses nasal septal perforation repair using the fascia lata-fat island graft technique performed by a single surgeon. Inclusion criteria involved completing 12-month follow-ups within a 3-year review period. Success rates were calculated and evaluated alongside patient characteristics. Results: The median (range) age of the 25 patients included in the study was 34 (25-45) years and 72.0% were men. The septal perforation size of all patients was >2 cm and the etiological cause in all of them was previous septal surgery. All patients were followed for 12 months. The perforation was completely closed in 23 of 25 patients (92%). Conclusion: Using a different graft with an open rhinoplasty approach, we achieved a high success rate in patients with large septal perforations, followed for 1 month with nasal stenting and an average follow-up duration of 12 months.

A Novel Technique for Septal Perforation Repair: Fascia Lata Graft.

BACKGROUND: Nasal septal perforation (NSP) is an anatomical defect involving the mucosa, cartilage/bone of the nasal septum, most commonly caused by septoplasty. Spontaneous healing of a perforated septum is rare; instead, it tends to worsen over time. Several surgical approaches have been described for NSP repair. In this study, the authors present a novel technique using only fascia lata graft for repairing NSP of various sizes. METHODS: The authors conducted a retrospective study, including 23 patients who underwent NSP repair between January 2020 and January 2022. Grafts were harvested, and the perforation was accessed through an open rhinoplasty approach, followed by insertion and suturing of the graft. RESULTS: The mean size of the septal perforations was 2.13 mm horizontally and 2.14 mm vertically. The mean follow-up period was 12 months. Complete closure of NSP was achieved in 21 out of 23 patients (91.30%). Among the cases, 17 were males (11.76%), and the age ranged from 20 to 43 years with a mean of 36.5. Eight cases (50%) were smokers. At 12 months postoperatively, 3 medium-sized NSPs were closed successfully, whereas 2 large NSPs did not achieve closure due to smoking. CONCLUSION: The fascia lata technique for NSP closure is a safe and reliable approach with a high success rate, which should be considered for patients with NSP.

Retrospective Evaluation of a Novel Nasal Tip Suture Technique.

Nasal tip surgery is a crucial aspect of rhinoplasty in which suture techniques play a significant role. Early suturing techniques focused primarily on repositioning alar cartilage remnants after they had undergone significant resection. The size, contour, and orientation of the medial and lateral crura are primary factors in creating a tip shape. In this review, we retrospectively evaluated obliquely oriented dome sutures with triangular dome resection that was performed in 540 rhinoplasty cases at Yunus Emre Hospital between 2015 and 2020. Dome-defining sutures were placed, and a triangular cartilage resection was performed. Subsequently, oblique sutures were placed to achieve the desired lateral cartilage position. Objective assessment of postoperative results (Objective Rhinoplasty Outcome Score), patient satisfaction assessments, and nasal examinations were conducted. The objective assessments of the esthetic results showed a significant improvement, with a mean score of 3.6, which represents a good to excellent outcome. Most patients were subjectively satisfied with the surgical outcomes of rhinoplasty. No serious complications, such as infection, recurrence of deviation, nasal obstruction, or esthetic problems such as dorsal irregularities, were observed after surgery. Overall, suturing techniques play an important role in determining the nasal tip shape. Our technique is beneficial for maintaining a favorable lateral crural position, leading to improved patient satisfaction.

Towards fully automated detection of epileptic disorders: a novel CNSVM approach with Clough-Tocher interpolation.

Epilepsy is a neurological disorder requiring specialists to scrutinize medical data at diagnosis. Diagnosis stage is both time consuming and challenging, requiring expertise in detection of epileptic seizures from multi-channel noisy EEG data. It is crucial that EEG signals be automatically classified in order to help experts detect epileptic seizures correctly. In this study, a novel hybrid deep learning and SVM technique is employed on a restructured EEG data. EEG signals were transformed into a two-dimensional image sequence. Clough-Tocher technique is employed for interpolation of the values obtained from the electrodes placed on the skull during EEG measurements in order to estimate the signal strength in the missing places over the picture. After the parameters in the deep learning architecture were optimized on the validation data, it is observed that the proposed technique's performance for classifying epilepsy moments over EEG signals demonstrated unmatched performance. This study fills a gap in the literature in terms of demonstrating a superior performance in automatic detection of epileptic episodes on a benchmark EEG data set and takes a substantial leap towards fully automated detection of epileptic disorders.

The Hemostatic Efficacy of Hydrogen Peroxide Irrigation to Control Intraoperative Bleeding in Adenoidectomy.

OBJECTIVE: Although adenoidectomy is generally accepted as a safe procedure, intraoperative hemorrhage is still the most common and potentially life-threating complication, especially in pediatric patients. We evaluated the clinical effect of intraoperative hydrogen peroxide irrigation with respect to hemostasis and operation times in pediatric adenoidectomy. METHODS: This was a prospective, randomized, double-blind study to investigate hydrogen peroxide solution in hemostasis in pediatric patients undergoing adenoidectomy. The patient, the surgeon, and the study nurse were blinded to the surgical technique used. RESULTS: One hundred seventeen (56 males and 61 females) consecutive pediatric patients with a mean age of 5.46±1.19 years were included in the study. There were 58 patients in the hydrogen peroxide group (median age: 6 years, mean age: 5.62±1.28 years) and 59 patients in the control group (median age: 5 years, mean age: 5.31±1.07 years). No significant difference was observed between the two groups with respect to age (p=0.151), gender (p=0.646), or adenoid size (p=0.767). On the other hand, the difference between the groups with respect to operation and hemostasis times was found to be statistically significant (p<0.001 for both). The average operation times were 8.67±0.48 min in the hydrogen peroxide group and 12.30±0.69 min in the control group. The average hemostasis times were 3.67±0.27 min in the hydrogen peroxide group and 5.73±0.31 min in the control group. CONCLUSION: Hydrogen peroxide solution can be effectively used in adenoidectomy for reducing intraoperative blood loss and for economic benefits.

Cinnamaldehyde is an effective anti-inflammatory agent for treatment of allergic rhinitis in a rat model.

OBJECTIVES: The effect of cinnamaldehyde on the treatment of allergic rhinitis (AR) was investigated in rat model. METHODS: Twenty-eight female Wistar albino rats were randomly divided into four groups: Group 1 (control) (C), Group 2 (AR with no treatment) (AR+NoTr), Group 3 (AR+Azelastine HCl) (AR+Aze), and Group 4 (AR+cinnamaldehyde) (AR+Cin). At day 21, AR+Aze rats were given an Azelastine HCl drop, and AR+Cin rats were given cinnamaldehyde intranasally. In all groups, allergic symptoms histopathological results were evaluated. RESULTS: The AR+NoTr group showed the worst allergic symptoms, cilia loss and greater inflammation. In the AR+Aze and AR+Cin groups, allergic symptom scores were higher than those in the control group. However, between AR+Aze and AR+Cin groups, there were no significant differences in the allergic symptom scores Histopathological analysis revealed vascular congestion and an increase in goblet cell numbers in the AR+Cin group. However, AR+Cin rat nasal mucosa had less plasma cell infiltration compared with the AR+NoTr group. In rats from the AR+Aze group, analysis of the nasal mucosa revealed less eosinophil infiltration than that seen in the AR+NoTr group. A lower score for mast cell (MC) infiltration was observed in the nasal mucosa of rats treated with Azelastine HCl compared with cinnamaldehyde. CONCLUSIONS: In this study we observed that both Azelastine HCl and cinnamaldehyde reduced allergic symptoms in an AR rat model. Cinnamaldehyde decreased vascular congestion as well as plasma cell, eosinophil, and inflammatory cell infiltration into the lamina propria.

Improved Gustatory Sensitivity in Morbidly Obese Patients After Laparoscopic Sleeve Gastrectomy.

INTRODUCTION: The reduction in the preferences for sweet and fat containing tastes in obese patients who underwent bariatric surgery was relatively well shown; however, there are only limited data on the changes in the sensitivity of other tastes like sour, salty, and bitter. METHODS: We investigated the changes in gustatory sensitivity of 52 morbidly obese patients (M/F, 22/30; age range, 19-60 years; BMI range, 32.5-63.0 kg/m(2)) after laparoscopic sleeve gastrectomy. The surgery was performed by the same surgeon using 5 ports technique. Gustatory sensitivity was tested preoperatively and 1 and 3 months after the surgery using standardized Taste Strips test. RESULTS: There was a statistically significant improvement in the taste acuity to sweet, sour, salty, and bitter tastants in morbidly obese patients after the laparoscopic sleeve gastrectomy during the follow-up period of 3 months. Median whole test scores of the patients were increased from 11.5 preoperatively to 14 in the first and third months. CONCLUSION: In this study, we were able to show the significant improvement in gustatory sensitivity of morbidly obese patients after laparoscopic sleeve gastrectomy for the first time in literature.

Hunger state affects both olfactory abilities and gustatory sensitivity.

Chemical senses such as odor, taste and appearance are directly related with appetite. Understanding the relation between appetite and flavor is getting more important due to increasing number of obese patients worldwide. The literature on the studies investigating the change in olfactory abilities and gustatory sensitivity mostly performed using food-related odors and tastes rather than standardized tests were developed to study olfaction and gustation. Therefore, results are inconsistent and the relationship between olfactory and gustatory sensitivity with respect to the actual state of human satiety is still not completely understood. Here, for the first time in literature, we investigated the change in both olfactory abilities and gustatory sensitivity in hunger and in satiety using 123 subjects (37 men, 86 women; mean age 31.4 years, age range 21-41 years). The standardized Sniffin' Sticks Extended Test and Taste Strips were used for olfactory testing and gustatory sensitivity, respectively. TDI score (range 1-48) was calculated as the collective scores of odor threshold (T), odor discrimination (D) and odor identification (I). The evaluation was performed in two successive days where the hunger state of test subjects was confirmed by blood glucose test strips (mean blood glucose level 90.0 ± 5.6 mg/dl in hunger and 131.4 ± 8.1 mg/dl in satiety). The results indicated statistically significant decrease in olfaction in satiety compared to hunger (mean TDI 39.3 ± 1.1 in hunger, 37.4 ± 1.1 in satiety, p < 0.001). The comparison of gustatory sensitivity indicated significantly higher sensitivity to sweet, sour and salty in hunger (p < 0.001), but significantly higher sensitivity to bitter tastant in satiety (p < 0.001). With this prospective study, we were able to show that both olfactory abilities and gustatory sensitivity were affected by hunger state.

Laparoscopic Sleeve Gastrectomy Improves Olfaction Sensitivity in Morbidly Obese Patients.

BACKGROUND: Olfactory abilities of the patients are known to be altered by eating and metabolic disorders, including obesity. There are only a number of studies investigating the effect of obesity on olfaction, and there is limited data on the changes in olfactory abilities of morbidly obese patients after surgical treatment. Here we investigated the changes in olfactory abilities of 54 morbidly obese patients (M/F, 22/32; age range 19-57 years; body mass index (BMI) range 30.5-63.0 kg/m(2)) after laparoscopic sleeve gastrectomy. METHOD: A laparoscopic sleeve gastrectomy was performed by the same surgeon using five-port technique. Olfactory abilities were tested preoperatively and 1, 3, and 6 months after the surgery using a standardized Sniffin' Sticks Extended Test kit. RESULTS: Analyses of variance indicated statistically significant improvement in T, D, and I scores of morbidly obese patients within time factors (preoperative vs. 1, 3, and 6 months; 1 vs. 3 and 6 months; and 3 vs. 6 months; p < 0.001 for all). There was a statistically significant improvement in overall TDI scores with an increase from 25 to 41 during the 6 months follow-up period (p < 0.001 for all). CONCLUSIONS: Here, for the first time in literature, we were able to show the significant improvement in olfactory abilities of morbidly obese patients after laparoscopic sleeve gastrectomy.

Prevalence of benign paroxysmal positional vertigo among motocross racers: a case-control study.

OBJECTIVES: This study aims to investigate the prevalence of benign paroxysmal positional vertigo (BPPV) among motocross racers after cross-country up and downhill activities. PATIENTS AND METHODS: This case-control study included 40 motocross racers (39 males, 1 female; mean age 26 years; range 21 to 43 years) and 40 healthy controls (30 males, 10 females; mean age 28 years; range 22 to 43 years) who had no hearing or balance problems. The Dix-Hallpike maneuver was applied to confirm the diagnosis of BPPV. Patients with BPPV were administered the Epley maneuver every week for one month and followed-up for treatment response assessment. RESULTS: Motocross and control groups were similar in terms of demographic and laboratory parameters. While BPPV was detected in four motocross racers (10%) according to Dix-Hallpike maneuver outcome and clinical findings, there was no BPPV in the control group. Of the motocross racers with BPPV, three had unilateral, one had bilateral disease. Of these patients, Epley maneuver was applied two times in two patients and three times in the other two patients. There was no vertigo or nystagmus in any of the patients with BPPV in one month. CONCLUSION: Intensive motocross activity is a cause of post-traumatic BPPV developing without head trauma. Large-scale, randomized controlled studies are needed to establish the post-traumatic etiology of BPPV in motocross racers.

Olfaction improvement after nasal septal perforation repair with the "cross-stealing" technique.

BACKGROUND: The surgical treatment of nasal septal perforation is known to improve nasal respiratory airflow and, thereby, should be beneficial to the patient's olfactory abilities. However, there are only limited data on the effect of nasal septal perforation repair (NSPR) on olfaction, and most studies reported contradictory results. OBJECTIVE: The aim of this prospective study was to investigate the change in the olfactory abilities of 42 patients with a primary concern of nasal septal perforation. METHODS: NSPR was performed with the "cross-stealing" technique. The inferior-based mucoperichondrial flap in one side and the superior-based mucoperichondrial flap from the other side of the nasal septum were passed to the opposite sides through the perforation. Surgery was completed by placing an interpositional graft between the flaps before suturing. The interpositional grafts were residual cartilage. The olfactory performance of the patients before and at 1, 3, and 6 months after the closure of the nasal septal perforation was measured by using an olfaction test kit. RESULTS: The success rate with complete closure of nasal septal perforation with the "cross-stealing" technique was 92.8%. Analysis of the data indicated statistically significant improvement in olfactory function scored as odor threshold (T), odor discrimination (D), odor identification (I) and TDI at 1, 3, and 6 months after NSPR (p < 0.001 for all). The mean TDI score evaluated 6 months after NSPR was improved by 64%. Analyses of variance indicated statistically significant improvement in olfactory scores within time factors were calculated as preoperative versus 1, 3, and 6 months; 1 versus 3 and 6 months; and 3 versus 6 months (p < 0.001 for all). Analysis of the present data indicates a beneficial effect of NSPR on olfactory abilities of patients with perforation. CONCLUSION: Our data on the short- and long-term olfactory abilities of 42 patients with nasal septal perforation after NSPR when using an olfaction test kit indicated statistically significant improvement in olfactory function.

Effectiveness of hyaluronic acid in post-tonsillectomy pain relief and wound healing: a prospective, double-blind, controlled clinical study.

OBJECTIVES: To find the effectiveness of hyaluronic acid in post-tonsillectomy pain relief and wound healing. METHODS: Fifty patients were included in this prospective, double-blind, controlled clinical study (20 males, 30 females mean age of 13.56 years). Hyaluronic acid was applied to one side and the other side was used as a control during tonsillectomy. Therefore, the same patient evaluated and scored the post-tonsillectomy pain, excluding individual bias. RESULTS: Results indicated that patients had significantly lower pain scores for hyaluronic acid treated side (p<0.001). At the end of two weeks follow-up period, the wound in the hyaluronic acid side was almost completely healed, indicating that the healing was faster with hyaluronic acid compared to control side (p<0.001). CONCLUSION: Hyaluronic acid could be recommended as an effective treatment for the management of post-tonsillectomy pain and wound healing.

Repair of nasal septal perforation using middle turbinate flap (monopedicled superiory based bone included conchal flap): a new unilateral middle turbinate mucosal flap technique.

UNLABELLED: The purpose of this study is to present a new approach for treatment of nasal septal perforation using middle turbinate flap. A consecutive study with follow-up of 31 patients with nasal septal perforation treated using middle turbinate flap. All patients underwent an endoscopic repair of nasal septal perforation using middle turbinate flap. All patients were followed for 18-24 months. Complete closure of the perforation was achieved in 29 of the 31 patients. Complete failure of the repair was observed in two patients. All patients showed nasal crusting in varying degrees for a period of 2-4 weeks. None of the patients showed nasal obstruction or atrophic rhinitis symptoms (stuffy nose, purulent postnasal drip, nasal crusting, epistaxis and anosmia) in postoperative follow-up. This technique provides a new method with many advantages compared to other techniques for closure of septal perforations. LEVEL OF EVIDENCE: IV.

Chorda tympani nerve analysis with electron microscopy in chronic suppurative otitis media.

CONCLUSION: Chronic suppurative otitis media causes some disturbance to the chorda tympani nerve (CTN), which may affect the facial nerve. It is not possible to perform a biopsy of the main truncus of the facial nerve, therefore studies of the CTN might show possible pathologic or physiologic changes of the facial nerve in the future. OBJECTIVES: The specific aim of this study was to investigate the effects of chronic suppurative otitis media on the CTN. METHODS: The tympanic segments of CTNs were collected for ultrastructural investigations in patients with chronic suppurative otitis media who underwent canal wall-down tympanoplasty. The study population comprised 10 patients, 7 males, 3 females; the age range was 16-66 years, and the mean age was 38. Qualitative and semiquantitative evaluations were performed on the specimens of CTN by electron microscopy. RESULTS: Our histopathologic examinations showed that there were changes of varying severity in all the CTNs such as scarcity of unmyelinated nerve fibers, Schwann cell nucleus condensation, scarcity of Schwann cell cytoplasm, adaxonal vacuolation and edema, myelin sheath disintegration, shrunken electron-dense axoplasm, increased collagen fibers, adaxonal circular lamellar complex, interstitial edema, and vacuolation of Schwann cell cytoplasm.

[Endoscopic approach in patients with choanal polyps]. / Koanal polipli olgularda endoskopik yaklasim.

OBJECTIVES: We evaluated the results of endoscopic treatment for choanal polyps. PATIENTS AND METHODS: Twelve patients (5 females, 7 males; mean age 25 years; range 10 to 49 years) underwent endoscopic surgery for choanal polyps. Preoperatively, all the patients were evaluated with endoscopic nasal cavity and nasopharyngeal examination and computed tomography of the paranasal sinuses. In addition, serum total and specific IgE levels were measured and prick test was performed. There were seven antrochoanal (58%), two ethmochoanal (17%), two sphenochoanal polyps, and one patient (8%) had a chonchachoanal polyp. Anterior ethmoidectomy and intranasal polypectomy were performed for ethmochoanal and sphenochoanal polyps, respectively. Two patients in whom antral part of the mucosa could not be clearly determined underwent transcanine sinoscopy. In all the patients, the mucosa giving rise to polyps was removed. Evaluations were made at one and six months and at the end of a year. RESULTS: The most common symptoms were nasal obstruction (70%) and nasal discharge (52%). Allergic tests were positive in two patients with antrochoanal polyps. The only complication was mild bleeding in two patients. No recurrences were encountered within a year follow-up. CONCLUSION: Endoscopic approach for choanal polyps can be applied at all ages and it is associated with low morbidity.

[Ectopic molar tooth in the maxillary sinus]. / Maksiller sinüste ektopik molar dis

The development of intranasal ectopic teeth is rare. Although they are more commonly seen in the palate and maxillary sinus, they can also be found in the mandibular condyle, coronoid process, and nasal cavity. A 30-year-old male patient presented with a complaint of headache. Computed tomography of the paranasal sinuses showed a bony mass in the right maxillary sinus wall, 1 cm in size. He did not have any history of maxillofacial trauma or operation. The mass was removed via a Caldwell-Luc procedure. It looked like a tooth. Histopathologic diagnosis was made as ectopic molar tooth. The patient was asymptomatic two weeks after the operation.