how to Update multiple Image in registration plugin?

I try to update multiple image upload in my plugin. I hook my code in admin profile part. I get image from usermeta table. My insert multiple image is work but update is not working. I create code for update multiple images as below:

   <?php

  /*
   * Admin Registration profile.
   *
   */

     add_action( 'show_user_profile', 'extra_user_profile_fields' );
     add_action( 'edit_user_profile', 'extra_user_profile_fields' );
    function extra_user_profile_fields( $user ) { ?>
    <h3><?php _e("Extra profile information", "blank"); ?></h3>

    <table class="form-table">
      <tr>       
           <th><label><?php _e("User Profile:"); ?></label></th>
            <td><input type="file" name="user_upload[]" id="user_upload" multiple="true"  /></td>
      </tr>
      <tr>
         <th></th>
        <td>
           <?php $images = get_the_author_meta( 'Images', $user->ID );
           //echo $images; //output is '279,280,281'.
           $image = explode(',',$images);
           foreach($image as $img)
            {
             ?>
              <img src="<?=wp_get_attachment_url( $img );?>" width="100" height="100" />
             <input type="checkbox" name="usergallery[]" value="<?=$img?>" />
                // check image for delete

            <?php } ?>


             </td>
          </tr>        

      </table>


     <?php
     }
      add_action( 'personal_options_update', 'save_extra_user_profile_fields' );
      add_action( 'edit_user_profile_update', 'save_extra_user_profile_fields' );

      function save_extra_user_profile_fields( $user_id ) {


        $attaches='';

        if ( ! function_exists( 'wp_handle_upload' ) ) {
            require_once( ABSPATH . 'wp-admin/includes/file.php' );
        }

        $upload_overrides = array( 'test_form' => false );
        $attach_array=array();

         $files=$_FILES['user_upload'];
        print_r($files);
        if(count($files['name'])>0)
        {
        foreach ($files['name'] as $key => $value) {
        if ($files['name'][$key]) {
            $file = array(
                'name'     => $files['name'][$key],
                'type'     => $files['type'][$key],
                'tmp_name' => $files['tmp_name'][$key],
                'error'    => $files['error'][$key],
                'size'     => $files['size'][$key]
              );
            $movefile=wp_handle_upload($file, $upload_overrides);
            $attach_array[]=$movefile['file'];
            }
        }
        $attach_id_array=array();
        require_once( ABSPATH . 'wp-admin/includes/image.php' );
        foreach($attach_array as $aa)
        {
            $filename = $aa;
            $filetype = wp_check_filetype( basename( $filename ), null );
            $wp_upload_dir = wp_upload_dir();
            $attachment = array(
                  'guid'           => $wp_upload_dir['url'] . '/' . basename( $filename ), 
                  'post_mime_type' => $filetype['type'],
                  'post_title'     => preg_replace( '/\.[^.]+$/', '', basename( $filename ) ),
                  'post_content'   => '',
                  'post_status'    => 'inherit'
              );
              $attach_id = wp_insert_attachment( $attachment, $filename,0 );
              $attach_data = wp_generate_attachment_metadata( $attach_id, $filename );
              wp_update_attachment_metadata( $attach_id, $attach_data );
              $attach_id_array[] = $attach_id;
        }
        $attaches=implode(',',$attach_id_array);
        }

        $existimages=get_the_author_meta( 'Images', $user_id );


        $existimages=explode(',',$existimages);
        $removeimages=$_POST['usergallery'];
        if(count($removeimages)>0)
        {
        $subset = array_diff($existimages,$removeimages);
        if(count($subset)>0)
        {
            $existimages = $subset;
        }
        else
        {
            $existimages='';
        }
        }
        $existimages=implode(',',$existimages);
        foreach($removeimages as $ri)
        {
            wp_delete_attachment( $ri,true); 
        }
        if($attaches!='')
        {
            $attaches = $attaches.','.$existimages;
        }
        else
        {
            $attaches = $existimages;
        }
       if ( !current_user_can( 'edit_user', $user_id ) ) { return false; }

       update_user_meta( $user_id, 'Images', $attaches);
         }

       ?>

This code is work at front end but not work in admin part. my other field is update successfully and work proper in admin part. So, please guide me.