Varicocele and left renal vein compression

Advanced upper urinary tract urothelial carcinoma is indistinguishable from renal infection by imaging: A case report

RATIONALE

The current diagnostic approach for urinary tract urothelial carcinoma (UTUC) relies on symptoms and imaging. Nevertheless, the diagnosis can be challenging in advanced cases presenting with atypical imaging and symptoms. This article presents an unreported case with atypical imaging and symptoms to provide some experience in diagnosing advanced UTUC.

PATIENT CONCERNS

A 55-year-old male patient was admitted to the hospital with a 2-month history of persistent left scrotal pain and intermittent left lower back pain.

DIAGNOSES

Computed tomography and magnetic resonance imaging revealed a left kidney infection. Paradoxically, the patient did not present with a fever, and the white blood cell count was within normal limits. To further clarify the diagnosis, urine cytology was performed. Surprisingly, malignant tumor cells were discovered. The diagnosis of UTUC was considered.

INTERVENTIONS

The patient underwent radical tumor resection.

OUTCOMES

The surgery was successfully performed. The patient received regular chemotherapy after surgery. No recurrence was found during the follow-up.

LESSONS

This case is a rare and enlightening clinical scenario. When imaging reveals renal infection accompanied by varicocele or renal vein embolism, it is crucial to consider the possibility of advanced UTUC.

Varicocele complicating an anterior lumbar interbody fusion: a case report

Anterior lumbar interbody fusion (ALIF) is performed for the surgical management of lumbar degenerative disc disease with excellent results, particularly for discogenic low back pain. Commonly reported complications associated with this approach include vessel injury, retrograde ejaculation, and ureteral and viscus organ injury. The development of a varicocele after ALIF has not been previously described in the literature. We report a case of varicocele in a 35-year-old patient who underwent ALIF via a left retroperitoneal approach. No intraoperative complications were identified. The postoperative course was uneventful. He was discharged from the hospital on the 5th postoperative day. Three months after surgery, he complained of discomfort and scrotal pain. Examination revealed a grade 3 varicocele according to the Dubin and Amelar classification. Scrotal Doppler US demonstrated dilatation of the veins of the pampiniform plexus. A lumbar CT scan revealed a bulky left spermatic vein closed to the ureter. The patient was treated with platelet anti-aggregation. He was seen at control intervals of 1, 3 and 5 months. Progress was seen as we had a regression of clinical signs. Varicocele appears as an uncommon complication of ALIF. After reviewing the literature, we describe the occurrence of a varicocele following ALIF, its pathophysiology, and its treatment options.

Association Between Left Renal Vein Entrapment and Varicocele Recurrence: A Cohort Study in 3042 Patients

The recurrence rates after varicocelectomy vary from 0.9% to 32.2%, especially for patients with the left renal vein entrapment (LRVE). This study aims to study the association between LRVE and varicocele recurrence, and to find the risk factors of LRVE. With the design of a cohort study, we included 3042 varicocele patients who would undergo modified inguinal microscope-assisted varicocelectomy (MHMV). 858 (28.21%) patients with LRVE were as the study group, and 2184 (71.79%) patients without LRVE were as the control group. Compared with the control group, BMI was lower (p < 0.001) in study group. Totally, 18 patients had recurrence after surgery, so the recurrence rate was 0.59%. Seventeen patients (1.98%) in study group and 1 patients (0.05%) in control group had recurrence, and significant statistical difference was found between the two groups (p < 0.001). The risk ratio of LRVE for varicocele recurrence is 43.27. In conclusion, the recurrence rate of our MHMV is the lowest (0.59%). There is association between LRVE and varicocele recurrence, and varicocele patients with LRVE have higher probability of recurrence rate after varicocelectomy. BMI could be a risk factor of LRVE. Thus, for varicocele patients, especially those with lower BMI, attentions should be payed to LRVE.

Perspectives in Pediatric Pathology, Chapter 20. Adolescent Varicocele

Varicocele is characterized by elongation, dilatation, and tortuosity of the veins draining the testis and its covers, causing circulatory reflux along the inner spermatic vein [ 1 ]. Varicocele results in progressive testicular lesions and, if untreated, can lead to testicular atrophy [ 2 ]. Varicocele is considered the most frequently identified cause of male infertility [ 3 ]. The mechanisms involved in varicocele formation are not well known and probably are multiple, differing from one patient to another.

Chronic constipation: Facilitator factor for development of varicocele

AIM: To evaluate the possible relationship between varicocele and chronic constipation.

METHODS: Between April 2009 and May 2010, a total of 135 patients with varicocele or constipation and 120 healthy controls were evaluated. Patients were divided into two groups. In both groups detailed medical history was taken and all patients were examined physically by the same urologist and gastroenterologist. All of them were evaluated by color Doppler ultrasonography. All patients with constipation, except for the healthy controls of the second group, underwent a colonoscopy to identify the etiology of the constipation. In the first group, we determined the rate of chronic constipation in patients with varicocele and in the second group, the rate of varicocele in patients with chronic constipation. In both groups, the rate of the disease was compared with age-matched healthy controls. In the second group, the results of colonoscopies in the patients with chronic constipations were also evaluated.

RESULTS: In the first group, mean age of the study and control groups were 22.9 ± 4.47 and 21.8 ± 7.21 years, respectively (P < 0.05). In the second group, mean age of the study and control groups were 52.8 ± 33.3 and 51.7 ± 54.3 years, respectively (P < 0.05). In the first group, chronic constipation was observed in 8 of the 69 patients with varicocele (11.6%) and 3 out of 60 in healthy controls (5%), respectively. In this regard, there was no statistical significance between varicocele patients and the healthy control (P = 0.37). In the second group, varicocele was observed in 16 of the 66 patients with chronic constipation (24.24%) and 12 out of 60 in healthy controls (20%) respectively. Similarly, there was no statistical significance between chronic constipation and healthy controls (P = 0.72). Internal/external hemorrhoids were detected in 4 of the 16 patients with chronic constipation and varicocele, in the second group. In the remaining 50 patients with chronic constipation 9 had internal/external hemorrhoids. In this regard, there was no statistical significance between chronic constipation and healthy controls (P = 0.80).

CONCLUSION: Chronic constipation may not be a major predictive factor for the development of varicocele, but it may be a facilitator factor for varicocele.

The comparison of two experimental rat varicocele models and their effect on sperm quality

OBJECTIVE

To develop a modified rat varicocele model.

METHODS

300 male Sprague-Dawley rats were selected. In 82 rats (classic group, CG), this was achieved by dissecting the left renal vein and ligating it using a 0.8-mm metal clip and 3-0 silk suture proximal to the inferior vena cava, followed by removal of the bar. In 118 rats (modified group, MG), in addition to the partial ligation of the left renal vein, the communicating branch was fully ligated. In 100 rats (sham operation group, SG), the left renal vein and communicating branches were dissected, but not ligated. The seminal fluid was aspirated and the diameters of the left spermatic veins were analyzed. Three months later, the examination was performed again.

RESULTS

The diameters were 0.16 ± 0.1 mm and 1.88 ± 0.1 mm before and after operation, respectively, in the CG (p < 0.01), and 0.15 ± 0.05 mm and 2.0 ± 0.1 mm in the MG (p < 0.01). Postsurgical diameters in the CG and MG were 1.88 ± 0.1 mm and 2.0 ± 0.1 mm (p > 0.5), and 0.16 ± 0.1 mm and 0.16 ± 0.11 mm in the SG (p > 0.5). Semen parameters in the CG had significant differences before and after the operation (p < 0.01), were significantly lower in the MG (p < 0.01), and had no significant differences in the SG (p > 0.5).

CONCLUSION

Simple partial ligation of the renal vein combined with ligation of the communicating branch leads to acceptable models for varicocele.

Nutcracker phenomenon and nutcracker syndrome

Nutcracker phenomenon refers to compression of the left renal vein, most commonly between the aorta and the superior mesenteric artery, with impaired blood outflow often accompanied by distention of the distal portion of the vein. The nutcracker syndrome (NCS) is the clinical equivalent of nutcracker phenomenon characterized by a complex of symptoms with substantial variations. Depending on specific manifestations, NCS may be encountered by different medical specialists. Although it may be associated with substantial morbidity, the diagnosis of NCS is often difficult and is commonly delayed. Diagnostic and treatment criteria are not well established, and the natural history of NCS is not well understood. We performed an initial review of the literature through MEDLINE, searching from 1950 to date and using the keywords nutcracker syndrome, nutcracker phenomenon, and renal vein entrapment. We performed additional reviews based on the literature citations of the identified articles. We attempted to elucidate clinical relevance of these conditions and their prominent features and to summarize professional experience.

Is varicocele associated with underlying venous abnormalities? Varicocele and the prostatic venous plexus

PURPOSE

We examined the pampiniform plexus and prostatic venous plexus using color Doppler ultrasonography and evaluated the relationship between varicocele and the prostatic venous plexus.

MATERIALS AND METHODS

This study included 209 men with a mean age of 35.3 years, of whom 68 had no varicoceles, 94 had a unilateral varicocele and 47 had bilateral varicoceles based on scrotal color Doppler ultrasonography. The diameter of the pampiniform plexus and prostatic venous plexus was measured using scrotal and transperineal ultrasonography, respectively. Peak retrograde and antegrade flow velocity of the prostatic venous plexus was measured by transperineal color Doppler ultrasonography.

RESULTS

Mean diameter, and peak and antegrade flow velocity of the prostatic venous plexus were greater in men with bilateral varicoceles than in those with a unilateral varicocele and in those without a varicocele (p <0.01). Moreover, men with a unilateral varicocele had a greater mean peak antegrade flow velocity than those without a varicocele (p <0.05). However, mean diameter and peak retrograde flow velocity were not different in men with a unilateral varicocele and those without a varicocele. In 10 men with a left clinical varicocele mean diameter, and peak retrograde and antegrade flow velocity of the prostatic venous plexus did not differ before vs after varicocele repair. In all men the diameter of the prostatic venous plexus positively correlated with the diameter of the right and left pampiniform plexus (p <0.0001).

CONCLUSIONS

Varicocele, especially bilateral varicoceles, may be associated with underlying venous abnormalities.

Anatomic and hemodynamic evaluation of renal venous flow in varicocele formation using color Doppler sonography with emphasis on renal vein entrapment syndrome

OBJECTIVE

To investigate the anatomic and hemodynamic properties of testicular venous drainage and its effects on varicocele formation and reflux using color Doppler ultrasound (US) with emphasis on renal vein entrapment syndrome.

MATERIAL AND METHODS

Upper abdominal and scrotal US examinations of 35 varicocele patients and 35 healthy male subjects were performed in the supine position during rest, during a Valsalva maneuver and in the erect position. The aortomesenteric angle and distance (AMA and AMD, respectively), peak mean velocities (PVs) and diameters of different segments of renal veins, testicular vein diameters and duration of flow inversion were measured.

RESULTS

In the varicocele group, the lateral segment of the left renal vein (LRV) had a larger diameter and slower PV, and the medial segment of the LRV had a smaller diameter and faster PV. The diameter of the dominant draining vein correlated with the PV of the medial and lateral segments of the LRV, whereas there was no correlation between the diameter of the dominant draining vein and the diameters of the right renal vein (RRV) and the lateral segment of the LRV or the PV of the RRV. The duration of flow inversion correlated with the diameter and PV of the medial segment of the LRV. No correlation between the diameters and PVs of the RRV and the lateral segment of the LRV was detected.

CONCLUSIONS

The decreases in the AMA, AMD, diameter of the medial segment of the LRV and PV of the lateral segment of the LRV, and the increases in the PV of the medial segment of the LRV and the diameter of the lateral segment of the LRV in varicocele patients in all positions suggest the entrapment or impingement of the left renal vein between the aorta and the superior mesenteric artery. This has been defined as the "nutcracker phenomenon", which is known to affect varicocele formation.

Hemodynamic investigation of the left renal vein in pediatric varicocele: Doppler US, venography, and pressure measurements

PURPOSE

To evaluate prospectively the hemodynamic state of the left renal vein with Doppler ultrasonography (US) and venography in pediatric patients with varicocele to assess the "nutcracker phenomenon."

MATERIALS AND METHODS

The institutional review board considered this study ethically sound, and parental informed consent was obtained for all subjects. Doppler US of the left renal vein was performed in 27 consecutive boys with varicocele (age range, 7-15 years; mean, 11.9 years) and in 20 boys without varicocele as control subjects (age range, 7-17 years; mean, 11.4 years). Doppler US was used to evaluate left renal vein diameters and peak velocities in the proximal left renal vein near the renal hilum and in the left renal vein between the aorta and superior mesenteric artery (aortomesenteric portion). The diameter ratios and peak velocity ratios between two sites were obtained. For statistical comparison of results, the t test was used. Left renal venography and renocaval pressure measurement were performed in 13 patients with varicocele. The Fisher exact test was used to evaluate the associations between the nutcracker phenomenon (renocaval pressure gradient >/=3 mm Hg) and the development of collateral veins.

RESULTS

The diameters of the proximal left renal vein and the peak velocities in the aortomesenteric portion of the left renal vein were significantly different between the varicocele group and the control group (P < .001). The diameter ratios (5.7 +/- 1.8 [standard deviation]) and peak velocity ratios (5.2 +/- 2.6) in patients with varicocele were significantly higher than those in control subjects (3.5 +/- 1.0 and 3.1 +/- 0.8, respectively) (P < .005). According to findings at left renal venography (n = 13), 10 patients (77%) met the criteria for the nutcracker phenomenon. The nutcracker phenomenon was significantly associated with the development of collateral veins (P = .035).

CONCLUSION

Doppler US and venography of the left renal vein can show hemodynamic changes of the left renal vein and depict the presence of the nutcracker phenomenon in pediatric varicocele.

Incidence of retro-aortic left renal vein and its relationship with varicocele

The retro-aortic left renal vein (RLRV) is a malformation characterized by the presence of a vessel that drains the left renal blood up to the inferior vena cava crossing behind the aortic artery. Varicocele is defined as venous dilation of the pampiniform plexus, and the left side is the most commonly affected. Several theories concerning the possible aetiology of varicocele are reviewed in the literature, but RLRV was not mentioned as an aetiologic factor of varicocele. in this study we investigated the percentage of RLRVs and their relation with varicocele. A total of 1,125 contrast-enhanced abdominal CT scans was examined to identify RLRVs. RLRVs were found in nine women (1.6%) and ten men (1.7%). We performed scrotal Doppler ultrasonography (US) for all affected men except one. Varicocele of varying degrees was found in seven of the nine male patients with RLRV (77%). RLRV could be one of the aetiological factors in the development of varicocele, and the cases with RLRV should be examined by scrotal Doppler US for the presence of varicocele.

The influence of left renal vein entrapment on outcome after surgical varicocele repair: a color Doppler sonographic demonstration

OBJECTIVE

To evaluate the impact of left renal vein entrapment on outcome after surgical varicocele repair using color Doppler sonography.

METHODS

Eighty-four men had varicoceles on color Doppler sonography (2 right sided, 74 left sided, and 8 bilateral), which were diagnosed on the basis of a venous diameter of 3 mm or greater and venous retrograde flow in the pampiniform plexus of veins during the Valsalva maneuver or when changing from a supine to an upright position. Diagnosis of the left renal vein entrapment was based on the following criteria: antero-posterior diameter of greater than 1 cm and peak velocity of less than 15 cm/s for the left renal vein at the mid portion and anteroposterior diameter of less than 0.2 cm and peak velocity of greater than 110 cm/s (or, alternatively, a diameter ratio and peak velocity ratio of >5) for the left renal vein between the aorta and superior mesenteric artery. All patients underwent surgical varicocele repair. In postoperative follow-up, we compared the presence of left renal vein entrapment with the frequency of varicocele recurrence.

RESULTS

Sixteen (19%) of 84 patients had left renal vein entrapment with a left-sided varicocele. Postoperatively (mean follow-up +/- SD, 19.3 +/- 11.7 months), 27 (32.2%) of 84 had varicocele recurrence, including all 16 patients with left renal vein entrapment and 11 (20.1%) of 68 patients without left renal vein entrapment. The varicocele recurrence rate was significantly greater in patients with left renal vein entrapment (P < .001, Fisher exact test).

CONCLUSIONS

The presence of left renal vein entrapment resulted in a significantly higher varicocele recurrence rate. Patients with varicoceles should routinely be evaluated for the presence of left renal vein entrapment before surgical repair.

Varicocele scintigraphy: a simplified screening method for the detection of spermatic vein reflux

Forty-three men underwent varicocele scintigraphy to exclude underlying varicocele as a possible cause of decreased semen quality. The total acquisition time for each study amounted to as little as 200 seconds. In four cases retrograde blood flow was seen in the left internal spermatic vein, with subsequent clear visualization of the pampiniform plexus. In three of four of these patients, pregnancy ensued after therapeutic intervention. Seven patients showed only increased scrotal activity locally, in the absence of retrograde blood flow. The remaining 32 patients showed a normal blood flow pattern. The existence of spermatic vein reflux in varicocele-related infertility is thought to be a major factor in proper patient selection for therapeutic ligation or embolization of the internal spermatic vein. It is suggested that this simplified scintigraphic method may be useful in the detection of retrograde blood flow in patients with varicocele, especially in small or subclinical varicocele.

Laparoscopic varicocele ligation

Varicocele, an abnormal dilatation of the pampiniform plexus, frequently contributes to male factor infertility. We performed laparoscopic varicocelectomy in 20 patients with varicoceles and abnormal seminal findings. The spermatic artery was identified and preserved in 13 patients and was clipped along with the veins in 7 patients including 1 patient with bilateral varicocele. The time required for the artery-ligating surgery ranged from 90 to 120 minutes with an average of 113.2 minutes, while the time needed for the artery-preserving technique ranged from 90 to 250 minutes with an average of 158.0 minutes. Some analgesics were administered to 11 patients, while the other 9 patients needed no analgesics. All patients were able to walk within 24 hours of the operation. The mean hospitalization period after the operation was 5.9 days. Sperm concentrations significantly improved postoperatively (p < 0.05). No difference in postoperative improvement of seminal findings was observed between artery-ligating and artery-preserving groups. A slight scrotal emphysema developed during the operation in 1 patient. Abdominal pain was experienced in 1 patient, but subsided within a few days. No serious complications were observed. The laparoscopic technique may replace routine open high ligation as the surgical treatment of choice, especially in patients with bilateral varicocele.

Percutaneous venography and embolization of the internal spermatic vein by spring coil for treatment of the left varicocele in children

The treatment of varicocele is controversial in boys and it is a contributing factor to male infertility. Recently it has been proposed that early therapy of a varicocele during childhood or adolescence may improve the prognosis of fertility. The authors review their experience with the diagnosis and management of left varicocele in 20 pediatric patients 6 to 15 years old. All were managed under local anesthesia by spermatic venography and percutaneous transcatheter embolization of the internal spermatic vein with spring coils. All achieved satisfactory occlusion, and during the follow-up, from 13 years to 9 months, there was only one recurrence, noted in a patient 6 months after the procedure. Complications were phlebitis of the pampiniform plexus, leading to swelling and erythema of the left scrotum, and mild flank pain; these symptoms resolved without sequelae. This is a safe and effective nonsurgical method of obliterating varicoceles in children, with a low morbidity rate and a short hospital stay.

The venous anatomy of experimental left varicocele: comparison with naturally occurring left varicocele in the human

OBJECTIVE

To determine the effect of experimental left varicocele on the anatomy of the veins serving the rat testis and to compare that anatomy to known patterns of vascular drainage from the human testis with and without varicocele.

DESIGN

Vascular maps were made of the effluent vessels from the rat testis in control animals and those with a 30-day experimental left varicocele. Consensus maps were arrived at and these were compared to published reports of the pertinent venous anatomy in humans with and without varicocele.

SETTING

Research laboratory.

RESULTS

The major route of blood leaving the rat testis was confirmed to be the spermatic vein, but nine common collaterals were also found to exist. Four of these collaterals became more pronounced with experimental varicocele as did several dilated perineal veins. These latter vessels all led to the iliac vein. The vasculature of the rat experimental varicocele model shares some important anatomical features with human varicocele anatomy.

CONCLUSIONS

Varicocele in humans and in the rat model causes a redistribution of blood flow from a route primarily out the spermatic vein to routes leading to the iliac vein. The redistribution is similar but not identical.

Laparoscopic procedure for varicocelectomy

OBJECTIVE

To report the results of laparoscopic varicocelectomy, a new surgical technique which presents minimal risks and provides an effective management of clinical varicoceles.

PATIENTS AND METHODS

Between July 1991 and November 1992, 45 laparoscopic varicocelectomies were performed in 44 patients whose ages ranged from 11 to 41 years. Endoscopic ligation, carried out according to the technique described by Palomo, was performed in 14 patients. In the remaining 30 patients ligation of 31 spermatic veins was performed according to Bernardi's procedure.

RESULTS

On post-operative follow-up symptoms disappeared in all the patients treated. Two of the patients showed persistent venous reflux on colour Doppler ultrasound examination.

CONCLUSIONS

The excellent identification of the anatomical structures, the minimal surgical trauma, the decrease in post-operative morbidity and the quick convalescence of the patients have made this new technique a viable alternative to routine open high ligation.

Efficacy of varicocele embolization versus ligation of the left internal spermatic vein for improvement of sperm quality

Efficacy of surgical varicocelectomy versus embolization of the spermatic vein was studied in 137 men diagnosed as suffering from left varicocele. The men were divided randomly into three groups according to the methods of treatment: A--embolization of the internal spermatic vein (51 men); B--Ivanissevich technique of high ligation of the spermatic veins (43 men); and C--Bernardi technique of high ligation (43 men). The groups were similar in terms of age, duration of infertility and possessed semen characterized as oligoteratoasthenozoospermia. The fertility of the female partners was evaluated carefully and they were found to be potentially fertile. Varicocele was diagnosed by at least two of the following methods: physical palpation during valsalva manoeuvre, venography, or scrotal scanning using the technetium pertechnetate radioactive method. Semen quality was assessed before treatment and at 3, 6 and 9 months post-treatment. Fecundity was followed-up for 18 months. The major results were: (i) Shrinkage of the varicocele was found in all three groups studied. The same rate of recurrence was recorded in the three groups (24%, 37% and 35% in groups A, B and C, respectively). (ii) Improvement of sperm quality was significant in groups A and B, with better results in group B. (iii) The pregnancy rate was significantly higher in group B, compared with A (38.2% vs. 20.6%; P less than 0.05). Thus, high ligation of the internal spermatic vein yields better results than low ligation or embolization as far as semen quality and pregnancy is concerned.

Laparoscopic varicocelectomy: preliminary report of a new technique

The use of varicocelectomy for the treatment of subfertility seems to be incontrovertible. However, there is a difference of opinion as to the proper surgical method of varicocele ablation. The inguinal and high retroperitoneal approaches are the most commonly accepted methods to date. However, significant postoperative morbidity is common and return to normal activity often is prolonged. Also, bilateral operations are being performed more commonly. These considerations have prompted many to search for alternative techniques. We developed a laparoscopic procedure that is as simple and effective as more traditional methods. In addition, it offers lower morbidity, allows for microscopic dissection with preservation of the spermatic artery and is amenable to bilateral ligation without a second incision. Ten patients 16 to 54 years old underwent laparoscopic ligation of the spermatic veins at the internal inguinal ring. The diagnosis was based on physical examination. Indications for the operation were infertility with a stress sperm pattern in 5 patients, testicular atrophy in 4 and scrotal pain in 1. Four patients underwent bilateral ligation. Preliminary followup showed resolution of the varicocele in all patients and disappearance of pain in the patient treated for this symptom. No morbidity related to this procedure has been encountered and all patients resumed normal activity within 2 days. We believe that this new method is a viable alternative for varicocelectomy.

Varicocele in children: "to treat or not to treat"--venographic and manometric studies

The management of varicocele is still controversial in spite of its high incidence (15%) in prepubertal boys and young adults and although it is believed to represent a major contributing factor to male subfertility. Fifty boys between 6 and 14 years of age were operated on for left varicocele, and a long segment of the left internal spermatic vein was excised. Thirty-four of them underwent preoperative retrograde left renal venography and pressure readings in both renal veins and inferior vena cava. In all 50 patients, intraoperative antegrade (via internal spermatic vein) left renal venography was performed. This examination revealed impaired renal venous drainage in 38 patients (group A) and normal venous return through the left renal vein in 12 patients (group B). In all 34 patients (from both groups) on whom retrograde venography was performed, there was marked renospermatic reflux. The pressure readings in the left renal vein were significantly increased in group A only. Our data strongly suggest that left varicocele is caused by renospermatic venous reflux and that this condition is probably irreversible. The reflux in group A is explained by the impaired venous drainage through the left renal vein. In group B, it is our impression that the reflux is a result of a congenitally valveless left internal spermatic vein. If varicocele is indeed a major cause for infertility, then our data logically point toward surgery.